Regenerate the amalgamated headers

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Move the dump tests of this branch to unit-json_view_dump.cpp
2026-10-28 12:30:52 +00:00 · 2026-10-18 10:51:27 +02:00 · 2026-10-18 10:51:26 +02:00 · 2026-10-18 10:51:25 +02:00 · 2026-10-18 10:51:24 +02:00 · 2026-10-18 10:51:23 +02:00
123 changed files with 3426 additions and 464615 deletions
@@ -108,16 +108,9 @@ The tests are located in [`tests/src/unit-*.cpp`](https://github.com/nlohmann/js
 are structured along the features of the library or the nature of the tests. Usually, it should be clear from the
 context which existing file needs to be extended, and only very few cases require creating new test files.

-When fixing a bug, edit `unit-regression3.cpp` and add a section referencing the fixed issue. Tests that need C++17 or
-C++20 go into `unit-regression3-cpp17.cpp` or `unit-regression3-cpp20.cpp` instead, so the large file is not rebuilt
-for every C++ standard. `unit-regression2.cpp` holds the older tests; the two files exist because a single one grew
-large enough for the MinGW linker to fail relocating it, so please keep adding to the smaller file rather than growing
-the larger one.
-
-To keep compile times down, several test files are compiled together as one translation unit. This sets a few rules
-for test files, such as giving file-scope helpers file-specific names. See the README in the
-[`tests`](https://github.com/nlohmann/json/tree/develop/tests) folder for how the tests are built and what to keep in
-mind when adding them.
+When fixing a bug, edit `unit-regression3.cpp` and add a section referencing the fixed issue.
+`unit-regression2.cpp` holds the older tests; the two files exist because a single one grew large enough for the
+MinGW linker to fail relocating it, so please keep adding to the smaller file rather than growing the larger one.

 #### Exceptions

@@ -37,7 +37,7 @@ jobs:
          path: pr/

  check:
-    runs-on: ubuntu-26.04
+    runs-on: ubuntu-latest
    env:
      MAIN_DIR: ${{ github.workspace }}/main
      INCLUDE_DIR: ${{ github.workspace }}/main/single_include/nlohmann
@@ -77,12 +77,13 @@ jobs:
          cd $MAIN_DIR

          # Built from this PR's own tools/macro_builder/main.cpp, not a
-          # develop checkout: unlike amalgamate.py, this tool has no other
-          # source of truth to check against (its own README documents that
-          # it must reproduce macro_scope.hpp byte for byte), so there is
-          # nothing to gain from checking out a separate copy, and doing so
-          # would make this step fail on a PR that adds support for a new
-          # dispatch table until that PR itself merges to develop.
+          # develop checkout: unlike amalgamate.py and generate_natvis.py,
+          # this tool has no other source of truth to check against (its
+          # own README documents that it must reproduce macro_scope.hpp
+          # byte for byte), so there is nothing to gain from checking out a
+          # separate copy, and doing so would make this step fail on a PR
+          # that adds support for a new dispatch table until that PR itself
+          # merges to develop.
          TMPDIR=$(mktemp -d ./macro_builder_check.XXXXXX)
          c++ -std=c++11 tools/macro_builder/main.cpp -o "$TMPDIR/macro_builder"
          "$TMPDIR/macro_builder" > "$TMPDIR/paste.hpp"
@@ -145,14 +146,14 @@ jobs:
      - name: Regenerate nlohmann_json.natvis
        run: |
          cd $MAIN_DIR
-          # The generator and its template are what this check verifies the
-          # committed natvis file against (which namespaces it lists, and
-          # what each entry looks like), so run this PR's copy rather than
-          # the develop checkout's: with develop's, a PR that changes either
-          # could never pass. generate_natvis.py loads the template from its
-          # own directory. Like the macro_builder step above, this only runs
-          # PR content in a job without credentials.
-          python3 tools/generate_natvis/generate_natvis.py $MAIN_DIR
+          # The template is what this check verifies the committed natvis
+          # file against, so take it from this PR rather than from the
+          # develop checkout: generate_natvis.py loads the template from its
+          # own directory, and with develop's copy a PR that changes the
+          # template could never pass. Like the macro_builder step above,
+          # this only renders PR content in a job without credentials.
+          cp tools/generate_natvis/nlohmann_json.natvis.j2 $NATVIS_TOOL_DIR/
+          python3 $NATVIS_TOOL_DIR/generate_natvis.py $MAIN_DIR

      - name: Build patch and check for differences
        id: diff
@@ -21,7 +21,7 @@ permissions:
 jobs:
  CodeQL-Build:

-    runs-on: ubuntu-26.04
+    runs-on: ubuntu-latest
    permissions:
      security-events: write

@@ -50,7 +50,7 @@ jobs:
          persist-credentials: false

      - name: "Run analysis"
-        uses: ossf/scorecard-action@fa7117db83c52d787ae5a89f350999701505d78e # v2.5.0
+        uses: ossf/scorecard-action@2d1146689b8cda280b9bc96326124645441f03bc # v2.4.4
        with:
          results_file: results.sarif
          results_format: sarif
@@ -33,7 +33,7 @@ jobs:
      security-events: write # for github/codeql-action/upload-sarif to upload SARIF results
      actions: read # only required for a private repository by github/codeql-action/upload-sarif to get the Action run status
    name: Scan
-    runs-on: ubuntu-26.04
+    runs-on: ubuntu-latest
    steps:
      - name: Harden Runner
        uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
@@ -32,7 +32,7 @@ jobs:
        run: cmake --build build --target ci_test_gcc

  ci_meson_install:
-    runs-on: ubuntu-26.04
+    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
        with:
@@ -77,7 +77,7 @@ jobs:
          cmake --build build-import-split

  ci_infer:
-    runs-on: ubuntu-26.04
+    runs-on: ubuntu-latest
    steps:
      - name: Harden Runner
        uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
@@ -106,7 +106,7 @@ jobs:
          if-no-files-found: ignore

  ci_static_analysis_ubuntu:
-    runs-on: ubuntu-26.04
+    runs-on: ubuntu-latest
    strategy:
      matrix:
        target: [ci_test_single_header, ci_cppcheck, ci_cpplint, ci_reproducible_tests, ci_non_git_tests, ci_offline_testdata, ci_reuse_compliance, ci_test_valgrind]
@@ -175,7 +175,7 @@ jobs:
        run: cmake --build build --target ${{ matrix.target }}

  ci_test_coverage:
-    runs-on: ubuntu-26.04
+    runs-on: ubuntu-latest
    steps:
      - name: Harden Runner
        uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
@@ -430,7 +430,7 @@ jobs:
        run: cmake --build build --target ci_nvhpc

  ci_emscripten:
-    runs-on: ubuntu-26.04
+    runs-on: ubuntu-latest
    steps:
      - name: Harden Runner
        uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
@@ -450,7 +450,7 @@ jobs:
        run: cmake --build build

  ci_test_documentation:
-    runs-on: ubuntu-26.04
+    runs-on: ubuntu-latest
    strategy:
      matrix:
        target: [ci_test_examples, ci_test_build_documentation, ci_test_documentation_mermaid]
@@ -361,10 +361,10 @@ add_custom_target(ci_test_coverage
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_coverage32
    COMMAND cd ${PROJECT_BINARY_DIR}/build_coverage32 && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure

-    COMMAND ${LCOV_TOOL} --directory . --capture --output-file json.info --rc branch_coverage=1 --rc geninfo_unexecuted_blocks=1 --ignore-errors mismatch --ignore-errors unused --ignore-errors inconsistent
-    COMMAND ${LCOV_TOOL} -e json.info ${SRC_FILES} --output-file json.info.filtered --rc branch_coverage=1 --ignore-errors unused --ignore-errors inconsistent
+    COMMAND ${LCOV_TOOL} --directory . --capture --output-file json.info --rc branch_coverage=1 --rc geninfo_unexecuted_blocks=1 --ignore-errors mismatch --ignore-errors unused
+    COMMAND ${LCOV_TOOL} -e json.info ${SRC_FILES} --output-file json.info.filtered --rc branch_coverage=1 --ignore-errors unused
    COMMAND ${CMAKE_SOURCE_DIR}/tests/thirdparty/imapdl/filterbr.py json.info.filtered > json.info.filtered.noexcept
-    COMMAND ${GENHTML_TOOL} --title "JSON for Modern C++" --legend --demangle-cpp --output-directory html --show-details --branch-coverage --ignore-errors inconsistent json.info.filtered.noexcept
+    COMMAND ${GENHTML_TOOL} --title "JSON for Modern C++" --legend --demangle-cpp --output-directory html --show-details --branch-coverage json.info.filtered.noexcept

    COMMENT "Compile and test with coverage"
 )
@@ -890,11 +890,11 @@ add_custom_target(ci_icpx
 # The following tests are excluded as they trigger known nvc++ 25.5 defects (not
 # library bugs); see https://github.com/nlohmann/json for tracking. Only the
 # affected language-standard variants are excluded so coverage is otherwise kept:
-#   - test-comparison-cpp20_cpp20, test-comparison_legacy-cpp20_cpp20
+#   - test-comparison_cpp20, test-comparison_legacy_cpp20
 #         miscompiles cross-type/<=> comparison (e.g. `-17 <= null`)
 #   - test-constructor1_cpp11
 #         std::initializer_list lifetime bug -> SIGSEGV
-#   - test-deserialization-cpp20_cpp20
+#   - test-deserialization_cpp20
 #         mangles the UTF-8 u8"" string literal in the char8_t (C++20) section
 add_custom_target(ci_nvhpc
    COMMAND ${CMAKE_COMMAND}
@@ -906,7 +906,7 @@ add_custom_target(ci_nvhpc
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_nvhpc
    # the pipes are escaped so the surrounding shell passes them to ctest verbatim
    # instead of treating them as shell pipe operators
-    COMMAND cd ${PROJECT_BINARY_DIR}/build_nvhpc && ${CMAKE_CTEST_COMMAND} --parallel ${N} --exclude-regex "test-comparison-cpp20_cpp20\\|test-comparison_legacy-cpp20_cpp20\\|test-constructor1_cpp11\\|test-deserialization-cpp20_cpp20" --output-on-failure
+    COMMAND cd ${PROJECT_BINARY_DIR}/build_nvhpc && ${CMAKE_CTEST_COMMAND} --parallel ${N} --exclude-regex "test-comparison_cpp20\\|test-comparison_legacy_cpp20\\|test-constructor1_cpp11\\|test-deserialization_cpp20" --output-on-failure
    COMMENT "Compile and test with NVIDIA HPC SDK (nvc++)"
 )

@@ -1 +1 @@
-cppcheck==1.5.3
+cppcheck==1.5.2
@@ -109,55 +109,6 @@ function(_json_test_apply_test_properties test_target properties_target)
    endif()
 endfunction()

-# for internal use by _json_test_add_test() and _json_test_add_unity_batch():
-# registers the CTest test <test_name>_cpp<cxx_standard> (plus its Valgrind
-# variant), which runs the executable target <test_target> with the arguments
-# in ARGN, and applies the test properties of the test- and standard-specific
-# interface targets
-function(_json_test_register_test test_name test_target cxx_standard)
-    set(ctest_name ${test_name}_cpp${cxx_standard})
-
-    if (JSON_FastTests)
-        add_test(NAME ${ctest_name}
-            COMMAND ${test_target} ${DOCTEST_TEST_FILTER} ${ARGN}
-            WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
-        )
-    else()
-        add_test(NAME ${ctest_name}
-            COMMAND ${test_target} ${DOCTEST_TEST_FILTER} ${ARGN} --no-skip
-            WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
-        )
-    endif()
-    set_tests_properties(${ctest_name} PROPERTIES LABELS "all" FIXTURES_REQUIRED TEST_DATA)
-
-    # apply standard-specific test properties
-    if(TARGET _json_test_interface__cpp_${cxx_standard})
-        _json_test_apply_test_properties(${ctest_name} _json_test_interface__cpp_${cxx_standard})
-    endif()
-
-    # apply test-specific test properties
-    if(TARGET _json_test_interface_${test_name})
-        _json_test_apply_test_properties(${ctest_name} _json_test_interface_${test_name})
-    endif()
-
-    # apply test- and standard-specific test properties
-    if(TARGET _json_test_interface_${test_name}_cpp_${cxx_standard})
-        _json_test_apply_test_properties(${ctest_name}
-            _json_test_interface_${test_name}_cpp_${cxx_standard}
-        )
-    endif()
-
-    if(JSON_Valgrind)
-        add_test(NAME ${ctest_name}_valgrind
-            COMMAND ${memcheck_command} $<TARGET_FILE:${test_target}> ${DOCTEST_TEST_FILTER} ${ARGN}
-            WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
-        )
-        set_tests_properties(${ctest_name}_valgrind PROPERTIES
-            LABELS "valgrind" FIXTURES_REQUIRED TEST_DATA
-        )
-    endif()
-endfunction()
-
 # for internal use by json_test_add_test_for()
 function(_json_test_add_test test_name file main cxx_standard)
    set(test_target ${test_name}_cpp${cxx_standard})
@@ -192,7 +143,45 @@ function(_json_test_add_test test_name file main cxx_standard)
        )
    endif()

-    _json_test_register_test(${test_name} ${test_target} ${cxx_standard})
+    if (JSON_FastTests)
+        add_test(NAME ${test_target}
+            COMMAND ${test_target} ${DOCTEST_TEST_FILTER}
+            WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+        )
+    else()
+        add_test(NAME ${test_target}
+            COMMAND ${test_target} ${DOCTEST_TEST_FILTER} --no-skip
+            WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+        )
+    endif()
+    set_tests_properties(${test_target} PROPERTIES LABELS "all" FIXTURES_REQUIRED TEST_DATA)
+
+    # apply standard-specific test properties
+    if(TARGET _json_test_interface__cpp_${cxx_standard})
+        _json_test_apply_test_properties(${test_target} _json_test_interface__cpp_${cxx_standard})
+    endif()
+
+    # apply test-specific test properties
+    if(TARGET _json_test_interface_${test_name})
+        _json_test_apply_test_properties(${test_target} _json_test_interface_${test_name})
+    endif()
+
+    # apply test- and standard-specific test properties
+    if(TARGET _json_test_interface_${test_name}_cpp_${cxx_standard})
+        _json_test_apply_test_properties(${test_target}
+            _json_test_interface_${test_name}_cpp_${cxx_standard}
+        )
+    endif()
+
+    if(JSON_Valgrind)
+        add_test(NAME ${test_target}_valgrind
+            COMMAND ${memcheck_command} $<TARGET_FILE:${test_target}> ${DOCTEST_TEST_FILTER}
+            WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+        )
+        set_tests_properties(${test_target}_valgrind PROPERTIES
+            LABELS "valgrind" FIXTURES_REQUIRED TEST_DATA
+        )
+    endif()
 endfunction()

 #############################################################################
@@ -211,14 +200,6 @@ endfunction()
 # Use NAME <name> to override the filename-derived test name.
 # Use FORCE to create the test regardless of the file containing
 # JSON_HAS_CPP_<version_number>.
-#
-# Tests that depend on the C++ standard (e.g., because they use the macros
-# JSON_HAS_FILESYSTEM, JSON_HAS_RANGES, or JSON_HAS_THREE_WAY_COMPARISON)
-# should not make the whole of a large unit-foo.cpp be rebuilt for every
-# standard. Put them into a separate file unit-foo-cpp<NN>.cpp (see, e.g.,
-# unit-items-cpp17.cpp) which wraps its content in #ifdef JSON_HAS_CPP_<NN>.
-# Then, unit-foo.cpp itself contains no JSON_HAS_CPP_<NN> and is only built for
-# C++11.
 # Test targets are linked against <main>.
 # CXX_STANDARDS defaults to "11".
 #############################################################################
@@ -262,314 +243,6 @@ function(json_test_add_test_for file)
    endforeach()
 endfunction()

-# for internal use by json_test_add_unity_tests(): sets <result> to whether the
-# (absolute) <file> is built for <cxx_standard>; same rule as in
-# json_test_add_test_for(): C++11 always, others only if the file contains
-# JSON_HAS_CPP_<cxx_standard> or <force> is set
-function(_json_test_unity_applies file cxx_standard force result)
-    set(${result} TRUE PARENT_SCOPE)
-    if(NOT ("${cxx_standard}" STREQUAL 11 OR force))
-        file(READ ${file} file_content)
-        string(FIND "${file_content}" JSON_HAS_CPP_${cxx_standard} has_cpp_found)
-        if(${has_cpp_found} EQUAL -1)
-            set(${result} FALSE PARENT_SCOPE)
-        endif()
-    endif()
-endfunction()
-
-# for internal use by json_test_add_unity_tests(): creates the executable
-# test-unity-<batch_name>_cpp<cxx_standard> from the (absolute) source files
-# in ARGN, which are #include-d by a generated source file, and registers one
-# CTest test per source file that runs only the test cases of that file; if
-# <private> is true, the generated file defines JSON_TESTS_PRIVATE first
-function(_json_test_add_unity_batch batch_name cxx_standard main private)
-    set(batch_target test-unity-${batch_name}_cpp${cxx_standard})
-    set(batch_source ${PROJECT_BINARY_DIR}/tests/unity/${batch_target}.cpp)
-
-    set(batch_content "// generated by cmake/test.cmake; do not edit\n")
-    if(private)
-        string(APPEND batch_content "// at least one file of this batch needs access to private members of the library\n")
-        string(APPEND batch_content "#define JSON_TESTS_PRIVATE\n")
-        # the files define the macro again; mark this definition as used, as
-        # -Wunused-macros reports an unused definition when it is redefined
-        string(APPEND batch_content "#ifdef JSON_TESTS_PRIVATE\n#endif\n")
-    endif()
-    foreach(file ${ARGN})
-        string(APPEND batch_content "#include \"${file}\" // NOLINT(bugprone-suspicious-include)\n")
-    endforeach()
-
-    # only touch the generated file if it changed to keep incremental builds incremental
-    set(old_content "")
-    if(EXISTS ${batch_source})
-        file(READ ${batch_source} old_content)
-    endif()
-    if(NOT "${old_content}" STREQUAL "${batch_content}")
-        file(WRITE ${batch_source} "${batch_content}")
-    endif()
-
-    add_executable(${batch_target} ${batch_source})
-    target_link_libraries(${batch_target} PRIVATE ${main})
-    set_target_properties(${batch_target} PROPERTIES
-        CXX_STANDARD ${cxx_standard}
-        CXX_STANDARD_REQUIRED ON
-    )
-    if(TARGET _json_test_interface__cpp_${cxx_standard})
-        target_link_libraries(${batch_target} PRIVATE _json_test_interface__cpp_${cxx_standard})
-    endif()
-
-    # rebuild the batch when one of its files changes, and show the files in IDEs;
-    # files that are also built standalone (VARIANT_FILES) are left out, as
-    # HEADER_FILE_ONLY is a per-file property and would also affect those targets
-    set_source_files_properties(${batch_source} PROPERTIES OBJECT_DEPENDS "${ARGN}")
-    foreach(file ${ARGN})
-        if(NOT file IN_LIST _json_test_unity_variant_files)
-            set_source_files_properties(${file} PROPERTIES HEADER_FILE_ONLY ON)
-            target_sources(${batch_target} PRIVATE ${file})
-        endif()
-    endforeach()
-
-    foreach(file ${ARGN})
-        get_filename_component(file_basename ${file} NAME_WE)
-        string(REGEX REPLACE "unit-(.+)" "test-\\1" test_name ${file_basename})
-
-        # run only the test cases defined in this file (and in the shared
-        # make_test_data_available.hpp if the file uses it)
-        file(READ ${file} file_content)
-        set(source_filter "--source-file=*${file_basename}.cpp")
-        string(FIND "${file_content}" make_test_data_available.hpp uses_test_data)
-        if(NOT ${uses_test_data} EQUAL -1)
-            string(APPEND source_filter ",*make_test_data_available.hpp")
-        endif()
-
-        _json_test_register_test(${test_name} ${batch_target} ${cxx_standard} "${source_filter}")
-    endforeach()
-endfunction()
-
-#############################################################################
-# json_test_add_unity_tests(
-#     FILES <files>...
-#     MAIN <main>
-#     [CXX_STANDARDS <version_number>...] [FORCE]
-#     [BATCH_SIZE <size>]
-#     [GROUPS <group>...]
-#     [VARIANT_FILES <files>...])
-#
-# Like calling json_test_add_test_for(<file> MAIN <main> ...) for each of the
-# <files>, but compiles several files together to speed up the build: for each
-# C++ standard, the files are split into batches of <size> files (default: 8)
-# and each batch is built as a single executable
-#
-#     test-unity-<pool><index>_cpp<version_number>
-#
-# whose generated source file #include-s the files of the batch (so they share
-# the template instantiations of the library). The tests are still named
-# test-foo_cpp<version_number>, one per file, but run the batch executable with
-# a doctest filter that selects the test cases of that file only.
-#
-# Files are only batched with files that agree on the macros defined before
-# the library is included: files that define at most JSON_TESTS_PRIVATE (or
-# macros derived from global compile definitions) form the pools "plain" and
-# "private". All other files are added with json_test_add_test_for() as usual,
-# as are files with test-specific build settings (see
-# json_test_set_test_options()) and the files listed in the explicit
-# exclusion list below.
-# Each <group> names a list variable json_test_unity_group_<group> of test file
-# stems (file names without "unit-" and ".cpp"). The batchable files of a group
-# are compiled together (regardless of BATCH_SIZE) as one executable
-#
-#     test-unity-<group>_cpp<version_number>
-#
-# so that related tests, which instantiate the same templates, share one
-# translation unit. A group may mix the pools "plain" and "private"; if any of
-# its files needs JSON_TESTS_PRIVATE, the whole group is built with it. Files
-# that cannot be batched stay standalone even if they are listed in a group.
-# Files in no group are batched by BATCH_SIZE as described above.
-# <files> in VARIANT_FILES are also built standalone with other settings, so
-# they are not marked as header-only sources of the batch.
-#############################################################################
-
-function(json_test_add_unity_tests)
-    cmake_parse_arguments(args "FORCE" "MAIN;BATCH_SIZE" "FILES;CXX_STANDARDS;VARIANT_FILES;GROUPS" ${ARGN})
-
-    if("${args_MAIN}" STREQUAL "")
-        message(FATAL_ERROR "Required argument MAIN <main> missing.")
-    endif()
-
-    if("${args_BATCH_SIZE}" STREQUAL "")
-        set(args_BATCH_SIZE 8)
-    endif()
-
-    if("${args_CXX_STANDARDS}" STREQUAL "")
-        set(args_CXX_STANDARDS 11)
-    endif()
-
-    if(args_FORCE)
-        set(force FORCE)
-    else()
-        set(force "")
-    endif()
-
-    set(_json_test_unity_variant_files "")
-    foreach(file ${args_VARIANT_FILES})
-        get_filename_component(file ${file} ABSOLUTE)
-        list(APPEND _json_test_unity_variant_files ${file})
-    endforeach()
-
-    # files that must not be merged into a batch: unit-32bit.cpp is only built
-    # for 32bit targets, and unit-no-macro-leak.cpp checks that including the
-    # library defines no unprefixed macro, which any other file would disturb
-    set(standalone_files unit-32bit.cpp unit-no-macro-leak.cpp)
-
-    set(harmless_macros "^(DOCTEST_.*|SKIP_TESTS_FOR_.*|JSON_TEST_DEPRECATED_FUNCTIONS_DELETED|JSON_TEST_STRICT_NUL_HANDLING_ENABLED|JSON_TEST_STRINGIZE)$")
-
-    # classify the files
-    set(plain_files "")
-    set(private_files "")
-    set(standalone_abs_files "")
-    foreach(file ${args_FILES})
-        get_filename_component(file_name ${file} NAME)
-        get_filename_component(file_basename ${file} NAME_WE)
-        string(REGEX REPLACE "unit-(.+)" "test-\\1" test_name ${file_basename})
-
-        set(batchable TRUE)
-        if(file_name IN_LIST standalone_files)
-            set(batchable FALSE)
-        endif()
-        if(TARGET _json_test_interface_${test_name})
-            set(batchable FALSE)
-        endif()
-        foreach(cxx_standard ${args_CXX_STANDARDS})
-            if(TARGET _json_test_interface_${test_name}_cpp_${cxx_standard})
-                set(batchable FALSE)
-            endif()
-        endforeach()
-
-        # files that suppress GCC's -Wnoexcept around their include of the
-        # library: the suppression has no effect once another file of the
-        # batch included the library first
-        if(batchable)
-            file(READ ${file} file_content)
-            string(FIND "${file_content}" "SUPPRESS_WARNING(\"-Wnoexcept\")" suppresses_noexcept)
-            if(NOT ${suppresses_noexcept} EQUAL -1)
-                set(batchable FALSE)
-            endif()
-        endif()
-
-        set(pool plain)
-        if(batchable)
-            # collect the macros (un)defined before the library is included
-            file(READ ${file} file_content)
-            string(FIND "${file_content}" "#include <nlohmann/" include_position)
-            if(NOT ${include_position} EQUAL -1)
-                string(SUBSTRING "${file_content}" 0 ${include_position} file_content)
-            endif()
-            string(REGEX MATCHALL "(^|\n)[ \t]*#[ \t]*(define|undef)[ \t]+[A-Za-z_0-9]+" directives "${file_content}")
-            foreach(directive ${directives})
-                string(REGEX REPLACE "^.*[ \t]([A-Za-z_0-9]+)$" "\\1" macro "${directive}")
-                if(macro MATCHES "${harmless_macros}")
-                    continue()
-                elseif("${macro}" STREQUAL JSON_TESTS_PRIVATE)
-                    set(pool private)
-                else()
-                    set(batchable FALSE)
-                endif()
-            endforeach()
-        endif()
-
-        get_filename_component(file_abs ${file} ABSOLUTE)
-        if(NOT batchable)
-            list(APPEND standalone_abs_files ${file_abs})
-            json_test_add_test_for(${file} MAIN ${args_MAIN} CXX_STANDARDS ${args_CXX_STANDARDS} ${force})
-            continue()
-        endif()
-        get_filename_component(file ${file} ABSOLUTE)
-        list(APPEND ${pool}_files ${file})
-    endforeach()
-
-    # resolve the explicit groups: group_<name>_files are the (absolute) files
-    # of the group, group_<name>_private tells whether one of them is private
-    set(grouped_files "")
-    foreach(group ${args_GROUPS})
-        if(NOT DEFINED json_test_unity_group_${group})
-            message(FATAL_ERROR "Unity test group '${group}' is not defined (json_test_unity_group_${group}).")
-        endif()
-        set(group_${group}_files "")
-        set(group_${group}_private FALSE)
-        foreach(stem ${json_test_unity_group_${group}})
-            # check against the source directory, because FILES may be filtered (JSON_TestShard)
-            get_filename_component(file ${CMAKE_CURRENT_SOURCE_DIR}/src/unit-${stem}.cpp ABSOLUTE)
-            if(NOT EXISTS ${file})
-                message(FATAL_ERROR "Unity test group '${group}' lists '${stem}', but ${file} does not exist.")
-            endif()
-            if(file IN_LIST grouped_files)
-                message(FATAL_ERROR "Unity test file unit-${stem}.cpp is listed in more than one group (second: '${group}').")
-            endif()
-            list(APPEND grouped_files ${file})
-
-            if(file IN_LIST standalone_abs_files)
-                message(STATUS "Unity test group '${group}': unit-${stem}.cpp cannot be batched and stays standalone")
-            elseif(file IN_LIST plain_files)
-                list(APPEND group_${group}_files ${file})
-                list(REMOVE_ITEM plain_files ${file})
-            elseif(file IN_LIST private_files)
-                list(APPEND group_${group}_files ${file})
-                list(REMOVE_ITEM private_files ${file})
-                set(group_${group}_private TRUE)
-            endif()
-        endforeach()
-    endforeach()
-
-    foreach(cxx_standard ${args_CXX_STANDARDS})
-        if(NOT compiler_supports_cpp_${cxx_standard})
-            continue()
-        endif()
-
-        # explicit groups: one batch per group
-        foreach(group ${args_GROUPS})
-            set(batch_files "")
-            foreach(file ${group_${group}_files})
-                _json_test_unity_applies(${file} ${cxx_standard} "${force}" applies)
-                if(applies)
-                    list(APPEND batch_files ${file})
-                endif()
-            endforeach()
-            if(batch_files)
-                _json_test_add_unity_batch(${group} ${cxx_standard} ${args_MAIN} ${group_${group}_private} ${batch_files})
-            endif()
-        endforeach()
-
-        # remaining files: batches of BATCH_SIZE files per pool
-        foreach(pool plain private)
-            set(is_private FALSE)
-            if(pool STREQUAL private)
-                set(is_private TRUE)
-            endif()
-
-            set(batch_files "")
-            set(batch_count 0)
-            set(batch_index 0)
-            foreach(file ${${pool}_files})
-                _json_test_unity_applies(${file} ${cxx_standard} "${force}" applies)
-                if(NOT applies)
-                    continue()
-                endif()
-
-                list(APPEND batch_files ${file})
-                math(EXPR batch_count "${batch_count} + 1")
-                if(batch_count EQUAL args_BATCH_SIZE)
-                    _json_test_add_unity_batch(${pool}${batch_index} ${cxx_standard} ${args_MAIN} ${is_private} ${batch_files})
-                    set(batch_files "")
-                    set(batch_count 0)
-                    math(EXPR batch_index "${batch_index} + 1")
-                endif()
-            endforeach()
-            if(batch_files)
-                _json_test_add_unity_batch(${pool}${batch_index} ${cxx_standard} ${args_MAIN} ${is_private} ${batch_files})
-            endif()
-        endforeach()
-    endforeach()
-endfunction()
-
 #############################################################################
 # json_test_should_build_32bit_test(
 #     <build_32bit_var> <build_32bit_only_var> <input>)
@@ -132,10 +132,6 @@ outside of a string, invalid) byte; see the [FAQ entry](../../home/faq.md#nul-by
 - [operator>>](../operator_gtgt.md) - deserialize from stream
 - [`JSON_STRICT_NUL_HANDLING`](../macros/json_strict_nul_handling.md) - opt in to rejecting a NUL byte in the input
  instead of treating it as end of input
- [`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md) - read a `std::istream` one character
-  at a time
- [`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md) - read a `FILE*` with the locking stdio
-  functions

 ## Version history

@@ -147,10 +143,6 @@ outside of a string, invalid) byte; see the [FAQ entry](../../home/faq.md#nul-by
 - Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
 - `JSON_STRICT_NUL_HANDLING` added in version 3.13.0 to optionally reject a NUL byte in the input instead of treating
  it as end of input; planned to become the default in version 4.0.0.
- Parsing from an `std::istream` scans the characters in its stream buffer in bulk in version 3.13.0
-  ([`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md)).
- Parsing from a `FILE*` locks the file once instead of once per character in version 3.13.0
-  ([`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md)).

 !!! warning "Deprecation"

@@ -112,16 +112,6 @@ By default, a `'\0'` (NUL) byte anywhere in the input is treated as end of input
 outside of a string, invalid) byte; see the [FAQ entry](../../home/faq.md#nul-bytes-in-the-input) for details and the
 [`JSON_STRICT_NUL_HANDLING`](../macros/json_strict_nul_handling.md) macro to opt into rejecting it instead.

-!!! tip "Performance"
-
-    Contiguous inputs (strings, string views, vectors, arrays, pointer ranges) are the fastest to parse. A
-    `#!cpp std::istream` comes close: the parser scans the characters its stream buffer holds in bulk, without reading
-    ahead, so the stream is left exactly where it would be after reading one character at a time. A `#!cpp FILE*` is
-    read one character at a time, but the file is locked only once, so other threads that use the same `FILE` object
-    wait until parsing is done. See [input sources and performance](../../features/parsing/index.md#input-sources-and-performance),
-    [`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md), and
-    [`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md).
-
 ## Examples

 ??? example "Example: (1) parse from a character array"
@@ -257,10 +247,6 @@ outside of a string, invalid) byte; see the [FAQ entry](../../home/faq.md#nul-by
 - [operator>>](../operator_gtgt.md) - deserialize from stream
 - [`JSON_STRICT_NUL_HANDLING`](../macros/json_strict_nul_handling.md) - opt in to rejecting a NUL byte in the input
  instead of treating it as end of input
- [`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md) - read a `std::istream` one character
-  at a time
- [`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md) - read a `FILE*` with the locking stdio
-  functions

 ## Version history

@@ -275,11 +261,6 @@ outside of a string, invalid) byte; see the [FAQ entry](../../home/faq.md#nul-by
  it as end of input; planned to become the default in version 4.0.0.
 - Extended empty-input detection to also cover an `std::istream` without a stream buffer, and fixed a crash
  (`std::terminate`) when parsing from an `std::istream` with `eofbit` in its exception mask, in version 3.13.0.
- Parsing from an `std::istream` scans the characters in its stream buffer in bulk in version 3.13.0
-  ([`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md) restores reading one character at a
-  time).
- Parsing from a `FILE*` locks the file once instead of once per character in version 3.13.0
-  ([`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md) restores `std::fgetc`).

 !!! warning "Deprecation"

@@ -116,10 +116,6 @@ consumer `sax` has a super-linear complexity.

 A UTF-8 byte order mark is silently ignored.

-When reading from a `#!c FILE*`, the file is locked while it is parsed. The lock is recursive, so the SAX handler may
-use the same file with stdio functions, but it must not wait for another thread that uses the same `FILE` object; see
-[`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md).
-
 ## Examples

 ??? example
@@ -141,10 +137,6 @@ use the same file with stdio functions, but it must not wait for another thread

 - [parse](parse.md) - deserialize from a compatible input
 - [accept](accept.md) - check if the input is valid JSON
- [`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md) - read a `std::istream` one character
-  at a time
- [`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md) - read a `FILE*` with the locking stdio
-  functions

 ## Version history

@@ -156,10 +148,6 @@ use the same file with stdio functions, but it must not wait for another thread
 - Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
 - `JSON_PRECISE_STREAM_POSITION` added in version 3.13.0 to optionally leave a `#!cpp std::istream` positioned right
  after the parsed value when `strict` is `#!cpp false`.
- Parsing from an `std::istream` scans the characters in its stream buffer in bulk in version 3.13.0
-  ([`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md)).
- Parsing from a `FILE*` locks the file once instead of once per character in version 3.13.0
-  ([`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md)).

 !!! warning "Deprecation"

@@ -123,6 +123,4 @@ Linear in the size of the JSON value `j`.
  that is not valid UTF-8 unchanged, as before; `strict` (the default if
  [`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled) throws `type_error.316`.
 - Throws `type_error.321` for a discarded value since version 3.13.0; previously, a discarded value nested in an
-  array or object was silently skipped, producing invalid BJData.
- Writes unsigned integers wider than 64 bits as high-precision numbers since version 3.13.0; previously, they were
-  silently truncated to 64 bits.
+  array or object was silently skipped, producing invalid BJData.
@@ -37,9 +37,8 @@ With (2), the bytes written before the exception remain in the output adapter.

 ## Exceptions

- Throws [out_of_range.407](../../home/exceptions.md#jsonexceptionout_of_range407) if `j` contains an integer outside
-  the range of int64 (an unsigned integer above 9223372036854775807, or, with a number type wider than 64 bits, any
-  integer beyond int64), which BON8 cannot represent
+- Throws [out_of_range.407](../../home/exceptions.md#jsonexceptionout_of_range407) if `j` contains an unsigned integer
+  above 9223372036854775807, which BON8 cannot represent
 - Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if `j` contains a string that is not
  valid UTF-8
 - Throws [type_error.321](../../home/exceptions.md#jsonexceptiontype_error321) if `j` or a value nested in it is
@@ -47,10 +47,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va

 - Throws [`type_error.317`](../../home/exceptions.md#jsonexceptiontype_error317) if the top-level type of the JSON value
  is not an object; example: `"to serialize to BSON, top-level type must be object, but is string"`
- Throws [`out_of_range.407`](../../home/exceptions.md#jsonexceptionout_of_range407) if `j` contains a signed integer
-  outside the range of int64 or an unsigned integer outside the range of uint64, which is only possible with a number
-  type wider than 64 bits; example:
-  `"integer number 9223372036854775808 cannot be represented by BSON as it does not fit int64"`
 - Throws [`out_of_range.409`](../../home/exceptions.md#jsonexceptionout_of_range409) if a key in the JSON object contains
  a null byte (code point U+0000); example: `"BSON key cannot contain code point U+0000 (at byte 2)"`
 - Throws [`out_of_range.412`](../../home/exceptions.md#jsonexceptionout_of_range412) if the length of a document, array,
@@ -123,5 +119,3 @@ pass before anything is written.
  that is not valid UTF-8 unchanged, as before; `strict` (the default if
  [`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled) throws `type_error.316` before anything
  is written.
- Throws `out_of_range.407` for integers that do not fit 64 bits since version 3.13.0; previously, integers of a
-  number type wider than 64 bits were silently truncated.
@@ -46,9 +46,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va

 ## Exceptions

- Throws [`out_of_range.407`](../../home/exceptions.md#jsonexceptionout_of_range407) if `j` contains an integer
-  outside [-2^64, 2^64-1], which is only possible with a number type wider than 64 bits; example:
-  `"integer number 18446744073709551616 cannot be represented by CBOR as it does not fit [-2^64, 2^64-1]"`
 - Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key in `j` is
  not valid UTF-8 and `error_handler` is `strict` (the default only if
  [`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled)
@@ -93,5 +90,3 @@ Linear in the size of the JSON value `j`.
  [`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled) throws `type_error.316`.
 - Throws `type_error.321` for a discarded value since version 3.13.0; previously, a discarded value nested in an
  array or object was silently skipped, producing invalid CBOR.
- Throws `out_of_range.407` for integers that do not fit 64 bits since version 3.13.0; previously, integers of a
-  number type wider than 64 bits were silently truncated.
@@ -46,9 +46,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va

 ## Exceptions

- Throws [`out_of_range.407`](../../home/exceptions.md#jsonexceptionout_of_range407) if `j` contains an integer
-  outside [-2^63, 2^64-1], which is only possible with a number type wider than 64 bits; example:
-  `"integer number 18446744073709551616 cannot be represented by MessagePack as it does not fit [-2^63, 2^64-1]"`
 - Throws [`out_of_range.412`](../../home/exceptions.md#jsonexceptionout_of_range412) if the length of a string, binary
  value, array, or object exceeds 4294967295, the maximum MessagePack can store; example:
  `"MessagePack length 4294967296 exceeds maximum of 4294967295"`
@@ -115,5 +112,3 @@ Linear in the size of the JSON value `j`.
  `number_unsigned_t`.
 - Throws `type_error.321` for a discarded value since version 3.13.0; previously, a discarded value nested in an
  array or object was silently skipped, producing invalid MessagePack.
- Throws `out_of_range.407` for integers that do not fit 64 bits since version 3.13.0; previously, integers of a
-  number type wider than 64 bits were silently truncated.
@@ -18,10 +18,10 @@ has `erase`; calling it on a read-only `basic_json_document` fails to compile (`
 1. Removes every member of `object` whose key is `key` (see [Notes](#notes) on duplicate keys) and returns how many
   were removed; `#!cpp 0` if `object` has no member with this key.
 2. Removes the element at index `idx` of `array`, which must already exist (`#!cpp idx < array.size()`).
-3. Removes the value the JSON pointer `ptr` refers to, relative to [`root()`](root.md). `ptr` must not be empty
-   ([`root()`](root.md) itself cannot be erased), and the *parent* of the target must already exist. The target is
-   removed as in 1. if the parent is an object (returns the number of removed members, `#!cpp 0` or more) and as in 2.
-   if it is an array (always returns `#!cpp 1`).
+3. Removes the value the JSON pointer `ptr` refers to, relative to [`root()`](root.md), and returns how many values
+   were removed: the *parent* of the target must already exist, and the target itself is removed as in 1. (an object
+   member; `#!cpp 0` or more) or 2. (an array element; always `#!cpp 1`). `ptr` must not be empty -- [`root()`](root.md)
+   itself cannot be erased.

 ## Template parameters

@@ -69,10 +69,10 @@ has `erase`; calling it on a read-only `basic_json_document` fails to compile (`
   [`out_of_range.404`](../../home/exceptions.md#jsonexceptionout_of_range404) (an empty token); otherwise (an
   object, or a primitive value the pointer's parent resolves to) throws what 1. throws.

-Overloads 1. and 2. also throw [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202)
-("view does not belong to this document") if `object`/`array` is a [discarded](../basic_json_view/is_discarded.md)
-view or a view of a *different* document. Overload 3. never throws `invalid_iterator.202`: it takes no view, and it
-always starts from this document's own [`root()`](root.md).
+Every overload also throws [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) ("view
+does not belong to this document") if `object`/`array` is a [discarded](../basic_json_view/is_discarded.md) view or a
+view of a *different* document (overloads 1-2 only; overload 3 always starts from this document's own
+[`root()`](root.md)).

 ## Complexity

@@ -92,10 +92,9 @@ always starts from this document's own [`root()`](root.md).

 Like [`set`](set.md) and [`push_back`](push_back.md), `erase` never moves an element's *value*: a view still
 referring to a removed member or element keeps showing what it last held (see [Edits](index.md#edits)) -- it just no
-longer appears when `array`/`object` is read, dumped, or iterated. What does change is the container's sequence of
-*links* to its elements: removing an element of `array` (2.) shifts the links to the elements after it by one, as
-[`insert`](insert.md) does in the other direction. *Every* iterator already taken over `array`/`object` is invalidated
-by an erase, not only those at or after the removed element, since the container may now use a different sequence.
+longer appears when `array`/`object` is read, dumped, or iterated. Removing an element of `array` (2.) does shift the
+*links* to the elements after it, the same way `insert`, `set`, or `push_back` on the same array would; any iterator
+already taken over `array`/`object` is invalidated by an erase, since it was walking the old layout.

 ## Examples

@@ -110,30 +110,17 @@ enum class image_check

 How thoroughly `load()` validates `image` before trusting it.

-`full` (the default)
-:   Checks everything the parser itself guarantees: structure and bounds; that every string is valid UTF-8 (and, for a
-    string still in the source text, that it contains no quote, backslash, or control character); and that every number
-    token is well-formed and matches the value stored for it. Strings and float tokens may share a range only if the
-    ranges are identical (as nodes that share a value do), and never overlap otherwise. Reading and serializing a
-    checked image is safe and always produces valid JSON, exactly as for a parsed document. This is the right choice for
-    an image from anything you do not fully control -- a file, a cache shared with other processes, a peer on the
-    network.
+| value    | checks                                                                                                    | guarantees |
+|----------|--------------------------------------------------------------------------------------------------------------|------------|
+| `full`   | everything the parser itself guarantees: structure and bounds; that every string is valid UTF-8 (and, for a string still in the source text, that it contains no quote, backslash, or control character); and that every number token is well-formed and matches the value stored for it; strings and float tokens may share a range only if the ranges are identical (as nodes that share a value do), and never overlap otherwise | reading and serializing a checked image is safe and always produces valid JSON, exactly as for a parsed document |
+| `bounds` | structure and bounds only -- that every offset and count in the node index stays inside the image            | reading and serializing stay memory-safe, but a crafted image can hold strings that are not valid UTF-8 or that serialize to invalid JSON ([`dump()`](../basic_json_view/dump.md) writes them unchanged or throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316)), and numbers whose values differ from their text |
+| `none`   | nothing                                                                                                       | images from a trusted source only -- reading a damaged image is undefined behavior |

-`bounds`
-:   Checks structure and bounds only: that every offset and count in the node index stays inside the image. So
-    `load()`, [`root()`](root.md), element access, and [`materialize()`](../basic_json_view/materialize.md) can never
-    read outside the image, even on a damaged one. It does *not* guarantee that the image describes valid JSON: a
-    string that a `full` check would have rejected can make [`dump()`](../basic_json_view/dump.md) write invalid UTF-8
-    or invalid JSON, or throw [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316), and a number can
-    read back with a value that does not match how it is spelled. An [editable document](../json_editable_document.md)
-    does not take such a string over: [`set`](set.md), [`push_back`](push_back.md) and [`insert`](insert.md) throw
-    `type_error.316` when they copy it from a view of the loaded document, and leave the editable document unchanged.
-    `bounds` skips scanning the text and the decoded strings, so it fits a cache your own process just wrote and reads
-    straight back, where damage would mean a bug or a hardware fault rather than adversarial input.
-
-`none`
-:   Checks nothing. Reading a damaged image is undefined behavior, so use it only for an image you trust as much as
-    your own memory.
+`full` is the default and the right choice for an image from anything you do not fully control -- a file, a cache
+shared with other processes, a peer on the network. `bounds` skips scanning the text and the decoded strings, so it
+fits a cache your own process just wrote and reads straight back, where damage would mean a bug or a hardware fault
+rather than adversarial input; it still cannot crash or read out of bounds. `none` skips validation entirely and
+should only be used for an image you trust as much as your own memory.

 **Lifetime.** Overloads 1 and 2 borrow `image`: it must stay alive and byte-for-byte unchanged for as long as the
 returned document, and any [view](../basic_json_view/index.md) taken from it, is used -- exactly like a document
@@ -147,6 +134,16 @@ returned document, and any [view](../basic_json_view/index.md) taken from it, is
    ("unknown format"). Use images to cache a document within one build of the library, or to hand one to another
    process running the *same* build on the *same* (little-endian) machine -- not as a long-term storage format.

+**What `image_check::bounds` does not guarantee.** A bounds-checked image can never make `load()`,
+[`root()`](root.md), element access, or [`materialize()`](../basic_json_view/materialize.md) read outside the image,
+so those stay safe on a damaged one. It does *not* guarantee that the image describes valid JSON: a string
+that a `full` check would have rejected can make [`dump()`](../basic_json_view/dump.md) write invalid UTF-8 or invalid
+JSON, or throw `type_error.316`, and a number can read back with a value that does not match how it is spelled.
+Reserve `bounds` for images you already trust to be well-formed, and use it only to skip the extra scan.
+An [editable document](../json_editable_document.md) does not take such a string over either:
+[`set`](set.md), [`push_back`](push_back.md) and [`insert`](insert.md) throw `type_error.316` when they copy it from
+a view of the loaded document, and leave the editable document unchanged.
+
 ## Examples

 ??? example "Caching a document, ownership, and a rejected image"
@@ -6,7 +6,7 @@ iterator begin() const noexcept;

 Returns an iterator to the first element of an array, or the first member value of an object, in **document order**
 -- the order the values appear in the source text, not sorted by key. A primitive value iterates as a range of one
-element (itself), and a `#!json null` value or a [discarded](is_discarded.md) view iterates as an empty range.
+element (itself); `#!json null` and a [discarded](is_discarded.md) view iterate as an empty range.

 ## Return value

@@ -5,8 +5,9 @@ iterator end() const noexcept;
 ```

 Returns an iterator to one past the last element of an array, one past the last member value of an object, in
-**document order** -- see [`begin()`](begin.md). A primitive value iterates as a range of one element (itself), and a
-`#!json null` value or a [discarded](is_discarded.md) view iterates as an empty range (`#!cpp begin() == end()`).
+**document order** -- see [`begin()`](begin.md). A primitive value iterates as a range of one element (itself);
+`#!json null` and a [discarded](is_discarded.md) view iterate as an empty range, so `#!cpp begin() == end()` for
+them.

 ## Return value

@@ -22,15 +22,15 @@ Moving the document itself does not invalidate its views: the index is heap-allo

 `basic_json_view` provides the read-only part of the `BasicJsonType` interface:

- the type-inspection functions
- element access
- lookup
- iteration
+- the type-inspection functions,
+- element access,
+- lookup,
+- iteration,
 - conversion: [`get<T>()`](get.md), [`get_string()`](get_string.md), [`number_token()`](number_token.md), and
-  [`materialize()`](materialize.md) to build the `BasicJsonType` value of a subtree on demand
+  [`materialize()`](materialize.md) to build the `BasicJsonType` value of a subtree on demand, and
 - comparison: [`operator==`](operator_eq.md) and [`operator!=`](operator_ne.md) compare two views, or a view and a
  `BasicJsonType` value, without ever building a `BasicJsonType` value for a view; no ordering comparison
-  (`#!cpp operator<`) is provided
+  (`#!cpp operator<`) is provided.

 [`operator[]`](operator%5B%5D.md), [`at`](at.md), [`contains`](contains.md), and [`value`](value.md) also accept a
 [`json_pointer`](../json_pointer/index.md). Unlike `basic_json`, there are no implicit conversion operators (no
@@ -16,10 +16,6 @@ header. See also the [macro overview page](../../features/macros.md).

 ## Parsing

- [**JSON_DISABLE_STREAM_BULK_SCAN**](json_disable_stream_bulk_scan.md) - read a `std::istream` one character at a time
-  instead of scanning its stream buffer in bulk
- [**JSON_DISABLE_UNLOCKED_FILE_IO**](json_disable_unlocked_file_io.md) - read a `FILE*` with `std::fgetc` instead of
-  locking it once and using the unlocked stdio functions
 - [**JSON_PRECISE_STREAM_POSITION**](json_precise_stream_position.md) - opt in to leaving an input stream positioned
  right after a parsed number
 - [**JSON_STRICT_BINARY_UTF8**](json_strict_binary_utf8.md) - opt in to checking strings for valid UTF-8 in the CBOR,
@@ -1,144 +0,0 @@
-# JSON_DISABLE_STREAM_BULK_SCAN
-
-```cpp
-#define JSON_DISABLE_STREAM_BULK_SCAN /* value */
-```
-
-When defined to `1`, parsing from a `#!cpp std::istream` reads the input one character at a time through the stream
-buffer, as in version 3.12.0 and earlier, instead of scanning the characters that the stream buffer already holds in
-bulk.
-
-The macro is an escape hatch for stream buffers that do not follow the usual contract of `std::basic_streambuf` (see
-the requirements on the stream buffer in the notes below). It does not change any result: values, exceptions, and the
-position of the stream after parsing are the same either way. Only the speed differs.
-
-## Default definition
-
-The default value is `0`: streams are scanned in bulk.
-
-```cpp
-#define JSON_DISABLE_STREAM_BULK_SCAN 0
-```
-
-## Notes
-
-!!! note "How streams are scanned"
-
-    A `std::streambuf` keeps the part of the input it has read but not yet handed out in its *get area*, the range
-    from `gptr()` to `egptr()`. A `std::filebuf`, for instance, reads the file in blocks of a few kilobytes into its get
-    area, and a `std::stringbuf` exposes its whole string as one get area.
-
-    When parsing from a `std::istream`, the parser scans this get area directly, with the same fast paths that it uses
-    for a `std::string`: runs of ordinary string characters, numbers, and indentation are recognized several bytes at a
-    time instead of being requested from the stream buffer one character at a time. When the parser reaches the end of
-    the get area, it asks the stream buffer for the next character as before, which makes the stream buffer refill its
-    get area.
-
-    The parser only reads characters that it would also have read one at a time, and it advances the stream buffer
-    exactly over the characters it consumes. Nothing is read ahead, buffered elsewhere, or put back. Therefore, the
-    stream is left exactly where it was left before:
-
-    - [`operator>>`](../operator_gtgt.md) and [`sax_parse`](../basic_json/sax_parse.md) with `strict = false` can still
-      read several values from one stream, and the stream can still be used with other `std::istream` functions after a
-      value has been read.
-    - With [`JSON_PRECISE_STREAM_POSITION`](json_precise_stream_position.md), the stream is still positioned right after
-      a parsed number.
-    - Exception messages, including the line, the column, and the last read token, are unchanged.
-
-!!! note "Performance"
-
-    Parsing from a `std::ifstream` or `std::istringstream` is typically 1.5 to 2 times as fast as before, and reading
-    many small values from one stream with `operator>>` 1.4 to 4 times as fast. Parsing from a stream is then within
-    about 10 to 20 % of first reading the whole file into a `std::string` and parsing that.
-
-    A stream buffer without a get area (one that only overrides `underflow()` and `uflow()` and hands out every
-    character from there) offers nothing to scan in bulk, so it is read one character at a time as before.
-
-!!! note "Requirements on the stream buffer"
-
-    The bulk scan relies on the following behavior, which every stream buffer of the standard library and every stream
-    buffer that keeps its input in its get area has:
-
-    - When `sgetc()` returns a character while `gptr() < egptr()`, that character is `*gptr()`; when `sbumpc()` returns
-      one, it was at `gptr()` before the call.
-    - Characters in the get area are not changed while they are in the get area.
-    - `underflow()` or `uflow()` either sets up a get area that holds the returned character at `gptr()` (or at
-      `gptr() - 1` after `uflow()`), or leaves the get area empty.
-
-    A stream buffer that returns characters from `uflow()` while leaving unrelated characters in its get area, or that
-    changes the characters in its get area in place, does not meet these requirements. Define the macro to `1` for
-    such stream buffers.
-
-!!! note "ABI compatibility"
-
-    The value of this macro is encoded in the [namespace](../../features/namespace.md) (tag `_dsbs`), resulting in
-    distinct symbol names. Translation units compiled with and without it can therefore be linked into the same program
-    without One Definition Rule (ODR) violations, but they cannot exchange instances of library types.
-
-!!! note "Other inputs"
-
-    Strings, string views, vectors, arrays, and pointer or iterator ranges over contiguous memory are scanned in bulk
-    anyway. Reading from a `#!cpp FILE*` is not affected by this macro; see
-    [`JSON_DISABLE_UNLOCKED_FILE_IO`](json_disable_unlocked_file_io.md) for that input.
-
-## Examples
-
-??? example "Example: reading values from a stream (default)"
-
-    The stream is scanned in bulk, and the values are read one after the other:
-
-    ```cpp
-    #include <iostream>
-    #include <sstream>
-    #include <nlohmann/json.hpp>
-
-    using json = nlohmann::json;
-
-    int main()
-    {
-        std::istringstream input(R"({"id": 1} {"id": 2} 42 rest)");
-        json j1, j2, j3;
-        input >> j1 >> j2 >> j3;  // {"id":1}, {"id":2}, 42
-
-        std::string word;
-        input >> word;            // "rest"
-    }
-    ```
-
-??? example "Example: reading one character at a time (macro defined to 1)"
-
-    With the macro, the same program reads the stream one character at a time, with the same results:
-
-    ```cpp
-    #define JSON_DISABLE_STREAM_BULK_SCAN 1
-    #include <iostream>
-    #include <sstream>
-    #include <nlohmann/json.hpp>
-
-    using json = nlohmann::json;
-
-    int main()
-    {
-        std::istringstream input(R"({"id": 1} {"id": 2} 42 rest)");
-        json j1, j2, j3;
-        input >> j1 >> j2 >> j3;  // {"id":1}, {"id":2}, 42
-
-        std::string word;
-        input >> word;            // "rest"
-    }
-    ```
-
-## See also
-
- [**parse**](../basic_json/parse.md) - deserialize from a compatible input
- [**operator>>**](../operator_gtgt.md) - deserialize from stream
- [**sax_parse**](../basic_json/sax_parse.md) - generate SAX events
- [**JSON_PRECISE_STREAM_POSITION**](json_precise_stream_position.md) - leave an input stream positioned right after a
-  parsed number
- [**JSON_DISABLE_UNLOCKED_FILE_IO**](json_disable_unlocked_file_io.md) - read a `FILE*` with the locking stdio
-  functions
- [Parsing: input sources and performance](../../features/parsing/index.md#input-sources-and-performance)
-
-## Version history
-
- Added in version 3.13.0.
@@ -1,115 +0,0 @@
-# JSON_DISABLE_UNLOCKED_FILE_IO
-
-```cpp
-#define JSON_DISABLE_UNLOCKED_FILE_IO /* value */
-```
-
-When defined to `1`, parsing from a `#!cpp FILE*` reads every character with `std::fgetc`, as in version 3.12.0 and
-earlier, instead of locking the file once and reading it with the unlocked stdio functions.
-
-It does not change any result: values, exceptions, and the position of the file after parsing are the same either way.
-Only the speed and the locking of the file differ (see the notes on locking below).
-
-Builds with MemorySanitizer use `std::fgetc` automatically, because the inline `getc_unlocked` of glibc reads the stdio
-buffer directly, which glibc (not instrumented) filled, and MemorySanitizer would report it as uninitialized.
-
-## Default definition
-
-The default value is `0`: the file is locked once and read with the unlocked stdio functions where they are available.
-
-```cpp
-#define JSON_DISABLE_UNLOCKED_FILE_IO 0
-```
-
-## Notes
-
-!!! note "Background"
-
-    The C standard library makes every `std::fgetc` call thread-safe by locking and unlocking the `FILE` object. When
-    parsing from a `FILE*`, the parser reads one character at a time, so this happens for every character of the input.
-
-    Instead, the parser locks the file once when parsing starts and unlocks it when parsing ends - also when an
-    exception is thrown - and reads the characters in between without locking:
-
-    | C library                                                  | functions                                          |
-    |------------------------------------------------------------|----------------------------------------------------|
-    | glibc (Linux), Apple (macOS, iOS), Android, FreeBSD, NetBSD, OpenBSD, DragonFly BSD | `flockfile`, `getc_unlocked`, `funlockfile` (POSIX) |
-    | Microsoft (MSVC, clang-cl)                                 | `_lock_file`, `_fgetc_nolock`, `_unlock_file`       |
-    | others (e.g., musl, MinGW, newlib)                         | `std::fgetc`, as before                             |
-
-    This makes parsing from a `FILE*` 3 to 4 times as fast with the Apple C library and 1.1 to 1.3 times as fast with
-    glibc, whose locking is cheaper. The binary formats ([`from_cbor`](../basic_json/from_cbor.md),
-    [`from_msgpack`](../basic_json/from_msgpack.md), ...) read from a `FILE*` the same way.
-
-!!! note "Locking"
-
-    While a value is parsed from a `FILE*`, the parsing thread holds the file's lock. The lock is recursive, so the
-    parsing thread itself - for instance, a [SAX](../json_sax/index.md) handler or a
-    [parser callback](../basic_json/parser_callback_t.md) - can keep using the file with stdio functions such as
-    `std::ftell`. Other threads that use the same `FILE` object wait until the parser is done. Before, they could
-    interleave their reads with the parser's, which made the parsed input unpredictable anyway.
-
-    A program in which a SAX handler or parser callback waits for **another** thread that uses the **same** `FILE`
-    object would deadlock. Define the macro to `1` for such programs.
-
-!!! note "ABI compatibility"
-
-    The value of this macro is encoded in the [namespace](../../features/namespace.md) (tag `_dufio`), resulting in
-    distinct symbol names. Translation units compiled with and without it can therefore be linked into the same program
-    without One Definition Rule (ODR) violations, but they cannot exchange instances of library types.
-
-!!! note "Other inputs"
-
-    Reading from a `#!cpp std::istream` is not affected by this macro; see
-    [`JSON_DISABLE_STREAM_BULK_SCAN`](json_disable_stream_bulk_scan.md) for that input.
-
-## Examples
-
-??? example "Example: parsing from a `FILE*` (default)"
-
-    The file is locked once while it is parsed:
-
-    ```cpp
-    #include <cstdio>
-    #include <nlohmann/json.hpp>
-
-    using json = nlohmann::json;
-
-    int main()
-    {
-        std::FILE* f = std::fopen("example.json", "rb");
-        json j = json::parse(f);  // f is locked until parse() returns
-        std::fclose(f);
-    }
-    ```
-
-??? example "Example: locking for every character (macro defined to 1)"
-
-    With the macro, every character is read with `std::fgetc`, with the same result:
-
-    ```cpp
-    #define JSON_DISABLE_UNLOCKED_FILE_IO 1
-    #include <cstdio>
-    #include <nlohmann/json.hpp>
-
-    using json = nlohmann::json;
-
-    int main()
-    {
-        std::FILE* f = std::fopen("example.json", "rb");
-        json j = json::parse(f);  // std::fgetc for every character
-        std::fclose(f);
-    }
-    ```
-
-## See also
-
- [**parse**](../basic_json/parse.md) - deserialize from a compatible input
- [**sax_parse**](../basic_json/sax_parse.md) - generate SAX events
- [**JSON_DISABLE_STREAM_BULK_SCAN**](json_disable_stream_bulk_scan.md) - read a `std::istream` one character at a
-  time
- [Parsing: input sources and performance](../../features/parsing/index.md#input-sources-and-performance)
-
-## Version history
-
- Added in version 3.13.0.
@@ -72,12 +72,6 @@ The default value is `0` (disabled — existing behavior is preserved).
    distinct symbol names. Translation units compiled with and without it can therefore be linked into the same program
    without One Definition Rule (ODR) violations, but they cannot exchange instances of library types.

-!!! note "Bulk scanning"
-
-    The parser scans the characters in the stream buffer in bulk (see
-    [`JSON_DISABLE_STREAM_BULK_SCAN`](json_disable_stream_bulk_scan.md)), but it never reads ahead. The stream is left
-    at the same position with and without bulk scanning, in both modes of this macro.
-
 !!! tip "Workaround without the macro"

    Separate the values in the stream with whitespace. The character consumed after a number is then the separator,
@@ -12,9 +12,8 @@ non-ASCII characters (e.g. CJK or emoji) this can validate several times faster.
 This is an **opt-in external dependency**. The library itself remains header-only and its behavior is unchanged: the
 same input is accepted or rejected either way, and every parse error is reported at the same position with the same
 message (simdutf is only used to fast-path *valid* runs; anything it flags falls back to the scalar path so the exact
-diagnostic is preserved). A `std::istream` uses simdutf for the characters its stream buffer holds (see
-[`JSON_DISABLE_STREAM_BULK_SCAN`](json_disable_stream_bulk_scan.md)); other streaming inputs (`FILE*`, wide strings,
-user-defined adapters) always use the scalar path.
+diagnostic is preserved). Streaming inputs (files, `std::istream`, wide strings, user-defined adapters) always use the
+scalar path.

 When `JSON_USE_SIMDUTF` is defined you must make the `simdutf.h` header available on the include path and link the
 simdutf library. When it is not defined, no simdutf header is included and there is no dependency.
@@ -39,6 +39,6 @@ the library.
 ## Version history

 - Added in version 3.11.0. Changed inline namespace name in version 3.11.2. Added the ABI tag `_dp` in
-  version 3.12.0, and the ABI tags `_bics`, `_psp`, `_snul`, `_sbu8`, `_ekmo`, `_dsbs`, `_dufio`, `_vns`, and
-  `_vssse3` in version 3.13.0; see
+  version 3.12.0, and the ABI tags `_bics`, `_psp`, `_snul`, `_sbu8`, `_ekmo`, `_vns`, and `_vssse3` in version
+  3.13.0; see
  [`nlohmann` Namespace](../../features/namespace.md#structure).
@@ -121,7 +121,6 @@ being read.
 - [`JSON_STRICT_NUL_HANDLING`](macros/json_strict_nul_handling.md) - opt in to rejecting a NUL byte in the input
  instead of treating it as end of input
 - [`JSON_PRECISE_STREAM_POSITION`](macros/json_precise_stream_position.md) - opt in to leaving the stream positioned right after a number
- [`JSON_DISABLE_STREAM_BULK_SCAN`](macros/json_disable_stream_bulk_scan.md) - read the stream one character at a time

 ## Version history

@@ -134,6 +133,3 @@ being read.
  crash (`std::terminate`) when `i` has `eofbit` in its exception mask, in version 3.13.0.
 - Changed to the strong exception safety guarantee in version 3.13.0: `j` is no longer left with a partially parsed
  value if parsing throws.
- Scans the characters in the stream buffer of `i` in bulk in version 3.13.0; the position of `i` after the call is
-  unchanged ([`JSON_DISABLE_STREAM_BULK_SCAN`](macros/json_disable_stream_bulk_scan.md) restores reading one character
-  at a time).
@@ -135,9 +135,6 @@ Note: Some modern features (like C++20 ranges or filesystem support) may be disa
  headers are included.
 - [x] On Windows, the library is compiled with `<Windows.h>` being included to detect and avoid common bugs (see
  [`unit-windows_h.cpp`](https://github.com/nlohmann/json/blob/develop/tests/src/unit-windows_h.cpp)).
- [x] The library is compiled with Qt's keyword macros (`slots`, `signals`, `emit`, `foreach`, `forever`) being defined
-  to make sure it does not use them as identifiers (see
-  [`unit-qt_keywords.cpp`](https://github.com/nlohmann/json/blob/develop/tests/src/unit-qt_keywords.cpp)).
 - [x] The library is compiled with exceptions disabled to support alternative means of error handling.

 ## Stable public API
@@ -14,8 +14,8 @@ C++ types, and finally serialize it again.
  [parsing untrusted input](parsing/untrusted_input.md).
 - [Zero-copy JSON views](json_view.md) — read a JSON text through a flat index instead of building a `json` tree;
  strings and numbers stay in the input and are only decoded when needed.
- [Editable documents](json_view.md#editing-a-document) — modify a parsed document without building a `json` tree.
- [Images](json_view.md#images) — save a parsed document and load it again without parsing it.
+  [Editable documents](json_view.md#editing-a-document) can also be modified, and [images](json_view.md#images) load a
+  parsed document again without parsing it.
 - [Comments](comments.md) and [trailing commas](trailing_commas.md) — opt-in relaxations of the JSON grammar.

 ## Accessing and modifying values
@@ -133,14 +133,6 @@ When defined, default parse and serialize functions for enums are excluded and h

 See [full documentation of `JSON_DISABLE_ENUM_SERIALIZATION`](../api/macros/json_disable_enum_serialization.md).

-## `JSON_DISABLE_STREAM_BULK_SCAN`
-
-When defined to `1`, parsing from a `#!cpp std::istream` reads one character at a time instead of scanning the
-characters that the stream buffer holds in bulk. Results are the same either way; the macro is an escape hatch for
-stream buffers that do not follow the usual `std::streambuf` contract. The default value is `0`.
-
-See [full documentation of `JSON_DISABLE_STREAM_BULK_SCAN`](../api/macros/json_disable_stream_bulk_scan.md).
-
 ## `JSON_DISABLE_TUPLE_REFERENCE_CONVERSION`

 When defined to `1`, a JSON value can no longer be created from a one-element `std::tuple` holding a reference to a JSON
@@ -149,14 +141,6 @@ is planned to become the default in version 4.0.0.

 See [full documentation of `JSON_DISABLE_TUPLE_REFERENCE_CONVERSION`](../api/macros/json_disable_tuple_reference_conversion.md).

-## `JSON_DISABLE_UNLOCKED_FILE_IO`
-
-When defined to `1`, parsing from a `#!cpp FILE*` reads every character with `std::fgetc`, which locks the file each
-time, instead of locking the file once and reading it with the unlocked stdio functions. Results are the same either
-way. The default value is `0`.
-
-See [full documentation of `JSON_DISABLE_UNLOCKED_FILE_IO`](../api/macros/json_disable_unlocked_file_io.md).
-
 ## `JSON_NO_AUTOMATIC_UDLS`

 When defined, `<nlohmann/json.hpp>` does not include `<nlohmann/json_literals.hpp>` with the user-defined string literals
@@ -23,10 +23,6 @@ The complete default namespace name is derived as follows:
    - [`JSON_STRICT_BINARY_UTF8`](../api/macros/json_strict_binary_utf8.md) defined non-zero appends `_sbu8`.
    - [`JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS`](../api/macros/json_use_objects_for_enum_keyed_maps.md) defined non-zero
      appends `_ekmo`.
-    - [`JSON_DISABLE_STREAM_BULK_SCAN`](../api/macros/json_disable_stream_bulk_scan.md) defined non-zero appends
-      `_dsbs`.
-    - [`JSON_DISABLE_UNLOCKED_FILE_IO`](../api/macros/json_disable_unlocked_file_io.md) defined non-zero appends
-      `_dufio`.
    - [`JSON_VIEW_NO_SIMD`](../api/macros/json_view_no_simd.md) defined appends `_vns`.
    - [`JSON_VIEW_USE_SSSE3`](../api/macros/json_view_use_ssse3.md) defined appends `_vssse3`.
 - The inline namespace ends with the suffix `_v` followed by the 3 components of the version number separated by
@@ -112,8 +108,6 @@ follows:
  ([`JSON_PRECISE_STREAM_POSITION`](../api/macros/json_precise_stream_position.md)), `_snul`
  ([`JSON_STRICT_NUL_HANDLING`](../api/macros/json_strict_nul_handling.md)), `_sbu8`
  ([`JSON_STRICT_BINARY_UTF8`](../api/macros/json_strict_binary_utf8.md)), `_ekmo`
-  ([`JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS`](../api/macros/json_use_objects_for_enum_keyed_maps.md)), `_dsbs`
-  ([`JSON_DISABLE_STREAM_BULK_SCAN`](../api/macros/json_disable_stream_bulk_scan.md)), `_dufio`
-  ([`JSON_DISABLE_UNLOCKED_FILE_IO`](../api/macros/json_disable_unlocked_file_io.md)), `_vns`
+  ([`JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS`](../api/macros/json_use_objects_for_enum_keyed_maps.md)), `_vns`
  ([`JSON_VIEW_NO_SIMD`](../api/macros/json_view_no_simd.md)), and `_vssse3`
  ([`JSON_VIEW_USE_SSSE3`](../api/macros/json_view_use_ssse3.md)) in version 3.13.0.
@@ -55,30 +55,6 @@ whitespace, because `operator>>` consumes the character that terminates a number
 [`JSON_PRECISE_STREAM_POSITION`](../../api/macros/json_precise_stream_position.md) is defined to `1` — see the
 [`operator>>` notes](../../api/operator_gtgt.md#notes) for details and examples.

-## Input sources and performance
-
-All inputs produce the same values and the same exceptions, but they are read in different ways, which makes some of
-them faster than others:
-
-| input                                                                                      | how it is read                                                                     |
-|--------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------|
-| strings, string views, string literals, contiguous containers, pointer or iterator ranges over contiguous memory | the whole input is scanned in bulk: runs of string characters, numbers, and indentation are recognized several bytes at a time |
-| `#!cpp std::istream` (`#!cpp std::ifstream`, `#!cpp std::istringstream`, ...)            | the characters the stream buffer holds are scanned in bulk like a string; the stream buffer is asked for more when they are used up |
-| `#!cpp FILE*`                                                                              | one character at a time, with the file locked once for the whole parse              |
-| other iterator ranges (e.g., `#!cpp std::list<char>`, `#!cpp std::istreambuf_iterator<char>`), wide strings | one character at a time                                                             |
-
-Parsing a file from a `#!cpp std::ifstream` is therefore only about 10 to 20 % slower than reading the whole file into a
-`#!cpp std::string` first and parsing that, and it needs no memory for a copy of the file. The stream is never read
-ahead: after parsing, it is positioned exactly as if every character had been read one at a time, so
-[`operator>>`](../../api/operator_gtgt.md) can still read several values from one stream (see also
-[JSON Lines](json_lines.md)).
-
-Two macros switch these optimizations off without changing any result:
-[`JSON_DISABLE_STREAM_BULK_SCAN`](../../api/macros/json_disable_stream_bulk_scan.md) for stream buffers that do not
-follow the usual `std::streambuf` contract, and
-[`JSON_DISABLE_UNLOCKED_FILE_IO`](../../api/macros/json_disable_unlocked_file_io.md) for programs in which another
-thread must use the same `#!cpp FILE` object while it is parsed.
-
 ## SAX vs. DOM parsing

 The library offers two parsing models:
@@ -194,8 +194,8 @@ packet-beta

 | Bytes | Field   | Type       | Contents                                                                                                                      |
 |-------|---------|------------|-------------------------------------------------------------------------------------------------------------------------------|
-| 0     | `kind`  | `uint8_t`  | the type, numbered as [`value_t`](../api/basic_json/value_t.md): 0 null, 1 object, 2 array, 3 string, 4 boolean, 5 signed integer, 6 unsigned integer, 7 float; 10 for a link (see below). There is no node for a discarded value: a [discarded](../api/basic_json_view/is_discarded.md) view has none |
-| 1     | `flags` | `uint8_t`  | bits 0-1: where a string's bytes (or a number's token) are (0: the source text, 1: the buffer of decoded strings, for strings with escapes, 2: the edit buffer); bit 2: the value of a boolean; bit 3: moved, bit 4: new, bit 5: linked (see below) |
+| 0     | `kind`  | `uint8_t`  | the type, numbered as [`value_t`](../api/basic_json/value_t.md): 0 null, 1 object, 2 array, 3 string, 4 boolean, 5 signed integer, 6 unsigned integer, 7 float; 10 for a link (see below) |
+| 1     | `flags` | `uint8_t`  | bits 0-1: where a string's bytes (or a number's token) are (0: the source text, 1: the buffer of decoded strings, for strings with escapes, 2: the edit buffer); bit 2: the value of a boolean; bits 3 and 4: moved and new (see below) |
 | 2-3   | `extra` | `uint16_t` | numbers: the number of integer digits (low byte) and fraction digits (high byte), 255 for more; objects: the number of their key hash index (1-based), or 0; otherwise 0 |
 | 4-7   | `off`   | `uint32_t` | where the value starts: the first byte after a string's opening quote (or its position in the buffer of decoded strings), the first byte of a number or literal, the bracket of an array or object |
 | 8-11  | `len`   | `uint32_t` | strings: the length after decoding; floats and literals: the length of the token; arrays and objects: the number of elements |
@@ -257,8 +257,6 @@ edited:
  sequence (a header node, then the entries), whose number is in `off`. The entries are links (`kind` 10), whose bytes
  8-15 hold the address of the value's node, so values never move.
 - A node written by an edit gets the flag *new* (bit 4): it has no position in the source text.
- A value that an entry of such a sequence links to gets the flag *linked* (bit 5): its extent in the parsed layout
-  (`next`) no longer matters, so a scalar can replace an array or object there in place.
 - Views of read-only documents compile without any of this: how views walk the index is a template parameter
  (`navigation<Editable>`).

@@ -972,19 +972,9 @@ double-precision number when `number_float_t` is `#!cpp float`.

 ### json.exception.out_of_range.407

-An integer number cannot be represented by the binary format it is serialized to:
-
- [BON8](../features/binary_formats/bon8.md) only stores integers that fit into int64, so
-  [`to_bon8`](../api/basic_json/to_bon8.md) throws for unsigned integers greater than 9223372036854775807.
- [CBOR](../features/binary_formats/cbor.md), [MessagePack](../features/binary_formats/messagepack.md), and
-  [BSON](../features/binary_formats/bson.md) store integers in at most 64 bits. With the default number types, every
-  integer fits, but a [`number_integer_t`](../api/basic_json/number_integer_t.md) or
-  [`number_unsigned_t`](../api/basic_json/number_unsigned_t.md) wider than 64 bits (e.g., `__int128`) can hold values
-  outside the range of the format: [-2^64, 2^64-1] for CBOR, [-2^63, 2^64-1] for MessagePack, and the range of int64
-  (signed integers) or uint64 (unsigned integers) for BSON.
-
-[UBJSON](../features/binary_formats/ubjson.md) and [BJData](../features/binary_formats/bjdata.md) never throw this
-exception, because they serialize integers beyond 64 bits as high-precision numbers.
+An unsigned integer number greater than 9223372036854775807 cannot be represented in the binary format. This exception
+is only thrown by [`to_bon8`](../api/basic_json/to_bon8.md), as [BON8](../features/binary_formats/bon8.md) has no
+unsigned 64-bit integer type.

 !!! note "Former occurrences"

@@ -993,17 +983,11 @@ exception, because they serialize integers beyond 64 bits as high-precision numb
    - Since version 3.9.0, integer numbers beyond int64 are serialized as high-precision UBJSON numbers.
    - Since version 3.12.0, integer numbers beyond int64 are serialized as uint64 BSON numbers.

-    Before version 3.13.0, CBOR, MessagePack, and BSON silently truncated integers wider than 64 bits, and BJData
-    truncated unsigned integers wider than 64 bits.
-
-!!! failure "Example messages"
+!!! failure "Example message"

    ```
    integer number 18446744073709551615 cannot be represented by BON8 as it does not fit int64
    ```
-    ```
-    integer number 1267650600228229401496703205376 cannot be represented by CBOR as it does not fit [-2^64, 2^64-1]
-    ```

 ### json.exception.out_of_range.408

@@ -235,17 +235,6 @@ Build the unit tests against the [simdutf](https://github.com/simdutf/simdutf) U
 its version is set by the cache variable `JSON_SIMDUTF_VERSION`. This option is `OFF` by default. Depends on
 `JSON_BuildTests`.

-### `JSON_TestUnityBuild`
-
-Build the unit tests in batches of several test files per executable to speed up compilation: the files of a batch are
-compiled as one translation unit, so the template instantiations of the library are shared. Every test file still gets
-its own CTest test (e.g., `test-foo_cpp11`), which runs only the test cases of that file from the shared executable.
-This option is `ON` by default (and `OFF` with MinGW). Set it to `OFF` to get one executable per test file, e.g., when
-debugging a single file. The number of files per executable is set by the cache variable `JSON_TestUnityBatchSize`
-(default: `8`). Related test files (e.g., all binary formats) are grouped explicitly in `tests/CMakeLists.txt`; each
-group is compiled as one executable per C++ standard regardless of the batch size, and only the remaining files are
-batched by size. Depends on `JSON_BuildTests`.
-
 ### `JSON_Valgrind`

 Execute the test suite with [Valgrind](https://valgrind.org). This option is `OFF` by default. Depends on `JSON_BuildTests`.
@@ -370,9 +370,7 @@ nav:
          - 'JSON_DELETE_DEPRECATED_FUNCTIONS': api/macros/json_delete_deprecated_functions.md
          - 'JSON_DIAGNOSTIC_POSITIONS': api/macros/json_diagnostic_positions.md
          - 'JSON_DISABLE_ENUM_SERIALIZATION': api/macros/json_disable_enum_serialization.md
-          - 'JSON_DISABLE_STREAM_BULK_SCAN': api/macros/json_disable_stream_bulk_scan.md
          - 'JSON_DISABLE_TUPLE_REFERENCE_CONVERSION': api/macros/json_disable_tuple_reference_conversion.md
-          - 'JSON_DISABLE_UNLOCKED_FILE_IO': api/macros/json_disable_unlocked_file_io.md
          - 'JSON_HAS_CPP_11, JSON_HAS_CPP_14, JSON_HAS_CPP_17, JSON_HAS_CPP_20, JSON_HAS_CPP_23, JSON_HAS_CPP_26': api/macros/json_has_cpp_11.md
          - 'JSON_HAS_EXPERIMENTAL_FILESYSTEM, JSON_HAS_FILESYSTEM': api/macros/json_has_filesystem.md
          - 'JSON_HAS_RANGE_VIEW_CONVERSION': api/macros/json_has_range_view_conversion.md
@@ -54,14 +54,6 @@
    #define JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS 0
 #endif

-#ifndef JSON_DISABLE_STREAM_BULK_SCAN
-    #define JSON_DISABLE_STREAM_BULK_SCAN 0
-#endif
-
-#ifndef JSON_DISABLE_UNLOCKED_FILE_IO
-    #define JSON_DISABLE_UNLOCKED_FILE_IO 0
-#endif
-
 #if JSON_DIAGNOSTICS
    #define NLOHMANN_JSON_ABI_TAG_DIAGNOSTICS _diag
 #else
@@ -110,18 +102,6 @@
    #define NLOHMANN_JSON_ABI_TAG_OBJECTS_FOR_ENUM_KEYED_MAPS
 #endif

-#if JSON_DISABLE_STREAM_BULK_SCAN
-    #define NLOHMANN_JSON_ABI_TAG_DISABLE_STREAM_BULK_SCAN _dsbs
-#else
-    #define NLOHMANN_JSON_ABI_TAG_DISABLE_STREAM_BULK_SCAN
-#endif
-
-#if JSON_DISABLE_UNLOCKED_FILE_IO
-    #define NLOHMANN_JSON_ABI_TAG_DISABLE_UNLOCKED_FILE_IO _dufio
-#else
-    #define NLOHMANN_JSON_ABI_TAG_DISABLE_UNLOCKED_FILE_IO
-#endif
-
 #ifdef JSON_VIEW_NO_SIMD
    #define NLOHMANN_JSON_ABI_TAG_VIEW_NO_SIMD _vns
 #else
@@ -139,9 +119,9 @@
 #endif

 // Construct the namespace ABI tags component
-#define NLOHMANN_JSON_ABI_TAGS_CONCAT_EX(a, b, c, d, e, f, g, h, i, j, k, l) json_abi ## a ## b ## c ## d ## e ## f ## g ## h ## i ## j ## k ## l
-#define NLOHMANN_JSON_ABI_TAGS_CONCAT(a, b, c, d, e, f, g, h, i, j, k, l) \
-    NLOHMANN_JSON_ABI_TAGS_CONCAT_EX(a, b, c, d, e, f, g, h, i, j, k, l)
+#define NLOHMANN_JSON_ABI_TAGS_CONCAT_EX(a, b, c, d, e, f, g, h, i, j) json_abi ## a ## b ## c ## d ## e ## f ## g ## h ## i ## j
+#define NLOHMANN_JSON_ABI_TAGS_CONCAT(a, b, c, d, e, f, g, h, i, j) \
+    NLOHMANN_JSON_ABI_TAGS_CONCAT_EX(a, b, c, d, e, f, g, h, i, j)

 #define NLOHMANN_JSON_ABI_TAGS                                       \
    NLOHMANN_JSON_ABI_TAGS_CONCAT(                                   \
@@ -153,8 +133,6 @@
            NLOHMANN_JSON_ABI_TAG_STRICT_NUL_HANDLING,               \
            NLOHMANN_JSON_ABI_TAG_STRICT_BINARY_UTF8,                \
            NLOHMANN_JSON_ABI_TAG_OBJECTS_FOR_ENUM_KEYED_MAPS,       \
-            NLOHMANN_JSON_ABI_TAG_DISABLE_STREAM_BULK_SCAN,          \
-            NLOHMANN_JSON_ABI_TAG_DISABLE_UNLOCKED_FILE_IO,          \
            NLOHMANN_JSON_ABI_TAG_VIEW_NO_SIMD,                      \
            NLOHMANN_JSON_ABI_TAG_VIEW_USE_SSSE3)

@@ -1342,32 +1342,14 @@ inline char* write_shortest(char* first, const zmij::shortest_decimal d) noexcep
    return end + (three ? 5 : 4);
 }

-/// the powers of ten up to 10^19 (all that fit in std::uint64_t)
-inline const std::array<std::uint64_t, 20>& powers_of_ten() noexcept
+/// the powers of ten up to 10^16
+inline const std::array<std::uint64_t, 17>& powers_of_ten_16() noexcept
 {
-    static const std::array<std::uint64_t, 20> powers =
+    static const std::array<std::uint64_t, 17> powers =
    {
        {
-            1u,
-            10u,
-            100u,
-            1000u,
-            10000u,
-            100000u,
-            1000000u,
-            10000000u,
-            100000000u,
-            1000000000u,
-            10000000000u,
-            100000000000u,
-            1000000000000u,
-            10000000000000u,
-            100000000000000u,
-            1000000000000000u,
-            10000000000000000u,
-            100000000000000000u,
-            1000000000000000000u,
-            10000000000000000000u
+            1u, 10u, 100u, 1000u, 10000u, 100000u, 1000000u, 10000000u, 100000000u, 1000000000u, 10000000000u,
+            100000000000u, 1000000000000u, 10000000000000u, 100000000000000u, 1000000000000000u, 10000000000000000u
        }
    };
    return powers;
@@ -1385,9 +1367,9 @@ JSON_HEDLEY_NON_NULL(1)
 JSON_HEDLEY_RETURNS_NON_NULL
 inline char* write_short_decimal(char* first, std::uint64_t digits, int count, int exp) noexcept
 {
-    JSON_ASSERT(digits >= powers_of_ten()[static_cast<std::size_t>(count - 1)] && count <= 15);
+    JSON_ASSERT(digits >= powers_of_ten_16()[static_cast<std::size_t>(count - 1)] && count <= 15);
    const int scale = 16 - count;
-    return write_shortest(first, zmij::shortest_decimal{digits * powers_of_ten()[static_cast<std::size_t>(scale)], exp - scale - 1, 0, false});
+    return write_shortest(first, zmij::shortest_decimal{digits * powers_of_ten_16()[static_cast<std::size_t>(scale)], exp - scale - 1, 0, false});
 }

 /// as write_short_decimal(), counting the digits (not 0, less than 10^15)
@@ -1398,7 +1380,7 @@ inline char* write_short_decimal(char* first, std::uint64_t digits, int exp) noe
    JSON_ASSERT(digits != 0 && digits < 1000000000000000u);
    // floor(log10(2^bits)) + 1 digits, or one less
    const int log2_bound = ((64 - count_leading_zeros(digits)) * 1233) >> 12;
-    const int count = log2_bound + (digits >= powers_of_ten()[static_cast<std::size_t>(log2_bound)] ? 1 : 0);
+    const int count = log2_bound + (digits >= powers_of_ten_16()[static_cast<std::size_t>(log2_bound)] ? 1 : 0);
    return write_short_decimal(first, digits, count, exp);
 }

@@ -14,12 +14,10 @@
 #include <cstdint> // uint32_t
 #include <cstring> // strlen
 #include <iterator> // begin, end, iterator_traits, random_access_iterator_tag, distance, next, reverse_iterator
-#include <limits> // numeric_limits
 #include <streambuf> // streambuf
 #include <string> // string, char_traits
 #include <type_traits> // enable_if, is_base_of, is_pointer, is_integral, remove_pointer
 #include <utility> // pair, declval
-#include <vector> // vector

 #ifndef JSON_NO_IO
    #include <cstdio>   // FILE *
@@ -32,33 +30,6 @@
 #include <nlohmann/detail/meta/type_traits.hpp>
 #include <nlohmann/detail/string_utils.hpp>

-#ifndef JSON_NO_IO
-    // Which unlocked stdio functions file_input_adapter uses (see
-    // JSON_DISABLE_UNLOCKED_FILE_IO): 1 = POSIX flockfile/getc_unlocked,
-    // 2 = Microsoft CRT _lock_file/_fgetc_nolock, 0 = none (std::fgetc, which
-    // locks the file for every character). Only C libraries known to declare
-    // the functions are listed; the macros are tested after <cstdio>, which
-    // defines __GLIBC__. MemorySanitizer builds always use std::fgetc: glibc's
-    // inline getc_unlocked reads the stdio buffer directly, which glibc (not
-    // instrumented) filled, so MemorySanitizer would report a false positive.
-    #if defined(__has_feature)
-        #if __has_feature(memory_sanitizer)
-            #define JSON_UNLOCKED_FILE_IO_MSAN 1
-        #endif
-    #endif
-
-    #if JSON_DISABLE_UNLOCKED_FILE_IO || defined(JSON_UNLOCKED_FILE_IO_MSAN)
-        #define JSON_UNLOCKED_FILE_IO 0
-    #elif defined(_MSC_VER)
-        #define JSON_UNLOCKED_FILE_IO 2
-    #elif defined(__GLIBC__) || defined(__APPLE__) || defined(__ANDROID__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
-        #define JSON_UNLOCKED_FILE_IO 1
-    #else
-        #define JSON_UNLOCKED_FILE_IO 0
-    #endif
-    #undef JSON_UNLOCKED_FILE_IO_MSAN
-#endif  // JSON_NO_IO
-
 NLOHMANN_JSON_NAMESPACE_BEGIN
 namespace detail
 {
@@ -85,35 +56,18 @@ class file_input_adapter
        : m_file(f)
    {
        JSON_ASSERT(m_file != nullptr);
-        lock();
    }

    // make class move-only
    file_input_adapter(const file_input_adapter&) = delete;
-    file_input_adapter(file_input_adapter&& rhs) noexcept
-        : m_file(rhs.m_file)
-    {
-        // the lock is owned by the thread, not the adapter: hand it over
-        rhs.m_file = nullptr;
-    }
+    file_input_adapter(file_input_adapter&&) noexcept = default;
    file_input_adapter& operator=(const file_input_adapter&) = delete;
    file_input_adapter& operator=(file_input_adapter&&) = delete;
-    ~file_input_adapter()
-    {
-        unlock();
-    }
+    ~file_input_adapter() = default;

    std::char_traits<char>::int_type get_character() noexcept
    {
-        // the file is locked for the lifetime of the adapter, so the
-        // per-character lock of std::fgetc can be skipped
-#if JSON_UNLOCKED_FILE_IO == 1
-        return getc_unlocked(m_file);
-#elif JSON_UNLOCKED_FILE_IO == 2
-        return _fgetc_nolock(m_file);
-#else
        return std::fgetc(m_file);
-#endif
    }

    // returns the number of characters successfully read
@@ -124,32 +78,6 @@ class file_input_adapter
    }

  private:
-    // Lock the file once for the whole parse instead of once per character.
-    // The lock is recursive, so fread() and the user's own stdio calls on the
-    // same thread keep working.
-    void lock() noexcept
-    {
-#if JSON_UNLOCKED_FILE_IO == 1
-        flockfile(m_file);
-#elif JSON_UNLOCKED_FILE_IO == 2
-        _lock_file(m_file);
-#endif
-    }
-
-    void unlock() noexcept
-    {
-        // a moved-from adapter has no file and holds no lock
-        if (m_file == nullptr)
-        {
-            return;
-        }
-#if JSON_UNLOCKED_FILE_IO == 1
-        funlockfile(m_file);
-#elif JSON_UNLOCKED_FILE_IO == 2
-        _unlock_file(m_file);
-#endif
-    }
-
    /// the file pointer to read from
    std::FILE* m_file;
 };
@@ -199,26 +127,15 @@ class input_stream_adapter
    input_stream_adapter& operator=(input_stream_adapter&) = delete;
    input_stream_adapter& operator=(input_stream_adapter&&) = delete;

-    input_stream_adapter(input_stream_adapter&& rhs) noexcept
-        : is(rhs.is), sb(rhs.sb)
 #if JSON_PRECISE_STREAM_POSITION
-        , lookahead(rhs.lookahead)
-#endif
-#if !JSON_DISABLE_STREAM_BULK_SCAN
-        , token_carry(std::move(rhs.token_carry))
-        , token_segment(rhs.token_segment)
-        , current_in_get_area(rhs.current_in_get_area)
-        , tracking_token(rhs.tracking_token)
-#endif
+    input_stream_adapter(input_stream_adapter&& rhs) noexcept
+        : is(rhs.is), sb(rhs.sb), lookahead(rhs.lookahead)
    {
        rhs.is = nullptr;
        rhs.sb = nullptr;
-#if JSON_PRECISE_STREAM_POSITION
        rhs.lookahead = false;
-#endif
    }

-#if JSON_PRECISE_STREAM_POSITION
    // Whether the character last returned by get_character() can be given back
    // to the input with release_lookahead().
    static constexpr bool supports_lookahead = true;
@@ -238,41 +155,17 @@ class input_stream_adapter
            sb->sbumpc();
        }

-#if !JSON_DISABLE_STREAM_BULK_SCAN
-        // sgetc() refills the get area if it is exhausted
-        const bool refill = streambuf_access::get_ptr(sb) == streambuf_access::get_end(sb);
-        if (JSON_HEDLEY_UNLIKELY(refill))
-        {
-            save_token_segment();
-        }
-#endif
-
        auto res = sb->sgetc();
        // set eof manually, as we don't use the istream interface.
        if (JSON_HEDLEY_UNLIKELY(res == std::char_traits<char>::eof()))
        {
            // there is nothing to step over next time
            lookahead = false;
-#if !JSON_DISABLE_STREAM_BULK_SCAN
-            current_in_get_area = false;
-#endif
            is->clear(is->rdstate() | std::ios::eofbit);
        }
        else
        {
            lookahead = true;
-#if !JSON_DISABLE_STREAM_BULK_SCAN
-            if (JSON_HEDLEY_UNLIKELY(refill))
-            {
-                // the peeked character is at gptr(), unless the streambuf has
-                // no get area
-                after_refill(res, streambuf_access::get_ptr(sb) != streambuf_access::get_end(sb));
-            }
-            else
-            {
-                current_in_get_area = true;
-            }
-#endif
        }
        return res;
    }
@@ -286,6 +179,13 @@ class input_stream_adapter
        lookahead = false;
    }
 #else
+    input_stream_adapter(input_stream_adapter&& rhs) noexcept
+        : is(rhs.is), sb(rhs.sb)
+    {
+        rhs.is = nullptr;
+        rhs.sb = nullptr;
+    }
+
    // std::istream/std::streambuf use std::char_traits<char>::to_int_type, to
    // ensure that std::char_traits<char>::eof() and the character 0xFF do not
    // end up as the same value, e.g., 0xFFFFFFFF.
@@ -294,37 +194,12 @@ class input_stream_adapter
    // stays consumed after parsing; see JSON_PRECISE_STREAM_POSITION.
    std::char_traits<char>::int_type get_character()
    {
-#if !JSON_DISABLE_STREAM_BULK_SCAN
-        // sbumpc() refills the get area if it is exhausted
-        const bool refill = streambuf_access::get_ptr(sb) == streambuf_access::get_end(sb);
-        if (JSON_HEDLEY_UNLIKELY(refill))
-        {
-            save_token_segment();
-        }
-#endif
-
        auto res = sb->sbumpc();
        // set eof manually, as we don't use the istream interface.
        if (JSON_HEDLEY_UNLIKELY(res == std::char_traits<char>::eof()))
        {
-#if !JSON_DISABLE_STREAM_BULK_SCAN
-            current_in_get_area = false;
-#endif
            is->clear(is->rdstate() | std::ios::eofbit);
        }
-#if !JSON_DISABLE_STREAM_BULK_SCAN
-        else if (JSON_HEDLEY_UNLIKELY(refill))
-        {
-            // the consumed character is at gptr() - 1, unless the streambuf
-            // has no get area and returned it from uflow()
-            const char* const next = streambuf_access::get_ptr(sb);
-            after_refill(res, next != nullptr && next != streambuf_access::get_begin(sb));
-        }
-        else
-        {
-            current_in_get_area = true;
-        }
-#endif
        return res;
    }
 #endif
@@ -343,165 +218,7 @@ class input_stream_adapter
        return res;
    }

-#if !JSON_DISABLE_STREAM_BULK_SCAN
-    // The lexer may scan the characters in the get area of the streambuf
-    // directly (SWAR fast paths). The get area is only a window into the
-    // input: it ends wherever the streambuf's buffer ends, and is refilled by
-    // the next get_character(). The lexer therefore keeps counting the
-    // position itself and treats the end of the window as "unknown", not as
-    // the end of the input.
-    static constexpr bool supports_bulk_scan = true;
-    static constexpr bool bulk_window = true;
-
-    // Pointer to the next unread character; only valid when
-    // bulk_remaining() > 0. The character before it is the one last returned
-    // by get_character().
-    const char* bulk_data() const
-    {
-        return current_end();
-    }
-
-    // Number of unread characters in the get area.
-    std::size_t bulk_remaining() const
-    {
-        if (!current_in_get_area)
-        {
-            return 0;
-        }
-        return static_cast<std::size_t>(streambuf_access::get_end(sb) - current_end());
-    }
-
-    // Consume @a n characters previously inspected via bulk_data(); the last
-    // of them becomes the character last returned by get_character().
-    void bulk_skip(std::size_t n)
-    {
-        JSON_ASSERT(n <= bulk_remaining());
-        // gbump() takes an int, but a get area (e.g., of a std::stringbuf) can
-        // be larger
-        constexpr auto max_bump = static_cast<std::size_t>((std::numeric_limits<int>::max)());
-        for (; n > max_bump; n -= max_bump)
-        {
-            streambuf_access::bump(sb, static_cast<int>(max_bump));
-        }
-        streambuf_access::bump(sb, static_cast<int>(n));
-    }
-
-    // The adapter keeps the current token for the lexer's error messages: the
-    // part in the get area is only remembered as a pointer, and copied out
-    // when the get area is about to be refilled.
-    static constexpr bool supports_token_tracking = true;
-
-    // Start a token with the characters read from now on. Until this is
-    // called, nothing is tracked (the binary readers never call it).
-    void begin_token() noexcept
-    {
-        tracking_token = true;
-        token_carry.clear();
-        token_segment = current_end();
-    }
-
-    // Start a new token with the character @a c last returned by
-    // get_character().
-    void mark_token_start(std::char_traits<char>::int_type c)
-    {
-        tracking_token = true;
-        token_carry.clear();
-        if (current_in_get_area)
-        {
-            token_segment = current_end() - 1;
-        }
-        else
-        {
-            token_segment = nullptr;
-            token_carry.push_back(std::char_traits<char>::to_char_type(c));
-        }
-    }
-
-    // Copy the characters read since mark_token_start() to @a out, without the
-    // last one if @a drop_last.
-    void copy_token(std::vector<char>& out, bool drop_last) const
-    {
-        out = token_carry;
-        if (token_segment != nullptr)
-        {
-            out.insert(out.end(), token_segment, current_end());
-        }
-        if (drop_last && !out.empty())
-        {
-            out.pop_back();
-        }
-    }
-#endif
-
  private:
-#if !JSON_DISABLE_STREAM_BULK_SCAN
-    // Reads the protected get-area pointers of any std::streambuf. Naming the
-    // members through a derived class makes forming the member pointers
-    // accessible; calling them on another streambuf object is then ordinary
-    // member access through a pointer to member.
-    struct streambuf_access : std::streambuf
-    {
-        static const char* get_ptr(std::streambuf* s)
-        {
-            return (s->*(&streambuf_access::gptr))();
-        }
-        static const char* get_end(std::streambuf* s)
-        {
-            return (s->*(&streambuf_access::egptr))();
-        }
-        static const char* get_begin(std::streambuf* s)
-        {
-            return (s->*(&streambuf_access::eback))();
-        }
-        static void bump(std::streambuf* s, int n)
-        {
-            (s->*(&streambuf_access::gbump))(n);
-        }
-    };
-
-    // one past the character last returned by get_character(), if that is in
-    // the get area
-    const char* current_end() const
-    {
-#if JSON_PRECISE_STREAM_POSITION
-        // the character is peeked at gptr() and not stepped over yet, unless
-        // it was given back with release_lookahead()
-        return streambuf_access::get_ptr(sb) + (lookahead ? 1 : 0);
-#else
-        return streambuf_access::get_ptr(sb);
-#endif
-    }
-
-    // the get area is about to be replaced: copy the token's part in it
-    void save_token_segment()
-    {
-        if (token_segment != nullptr)
-        {
-            token_carry.insert(token_carry.end(), token_segment, streambuf_access::get_end(sb));
-            token_segment = nullptr;
-        }
-    }
-
-    // character @a c was just read into a new get area (@a in_get_area) or
-    // returned without one
-    void after_refill(std::char_traits<char>::int_type c, bool in_get_area)
-    {
-        current_in_get_area = in_get_area;
-        if (!tracking_token)
-        {
-            return;
-        }
-        if (in_get_area)
-        {
-            token_segment = current_end() - 1;
-        }
-        else
-        {
-            token_carry.push_back(std::char_traits<char>::to_char_type(c));
-        }
-    }
-#endif
-
 #if JSON_PRECISE_STREAM_POSITION
    // Step over the character last returned by get_character(). The character
    // has already been peeked successfully, so for every streambuf with a get
@@ -523,16 +240,6 @@ class input_stream_adapter
    /// whether get_character() peeked a character that is not consumed yet
    bool lookahead = false;
 #endif
-#if !JSON_DISABLE_STREAM_BULK_SCAN
-    /// the part of the current token that was in earlier get areas
-    std::vector<char> token_carry{}; // NOLINT(readability-redundant-member-init)
-    /// start of the current token's part in the get area, or nullptr
-    const char* token_segment = nullptr;
-    /// whether the character last returned by get_character() is in the get area
-    bool current_in_get_area = false;
-    /// whether a token is tracked at all; the binary readers never start one
-    bool tracking_token = false;
-#endif
 };
 #endif  // JSON_NO_IO

@@ -166,43 +166,6 @@ constexpr bool input_adapter_supports_bulk_scan(std::false_type /*detected*/)
    return false;
 }

-// Detect whether an input adapter keeps the current token itself and can
-// hand it out on demand (see input_stream_adapter::supports_token_tracking),
-// so the lexer need not copy every scanned character into token_string.
-template<typename InputAdapterType>
-using detect_supports_token_tracking = decltype(InputAdapterType::supports_token_tracking);
-
-template<typename InputAdapterType>
-constexpr bool input_adapter_supports_token_tracking(std::true_type /*detected*/)
-{
-    return InputAdapterType::supports_token_tracking;
-}
-
-template<typename InputAdapterType>
-constexpr bool input_adapter_supports_token_tracking(std::false_type /*detected*/)
-{
-    return false;
-}
-
-// Detect whether the contiguous block of a bulk-scan adapter is only a window
-// into the input (see input_stream_adapter::bulk_window): its end is not the
-// end of the input, so a token that touches it must be finished character by
-// character.
-template<typename InputAdapterType>
-using detect_bulk_window = decltype(InputAdapterType::bulk_window);
-
-template<typename InputAdapterType>
-constexpr bool input_adapter_bulk_window(std::true_type /*detected*/)
-{
-    return InputAdapterType::bulk_window;
-}
-
-template<typename InputAdapterType>
-constexpr bool input_adapter_bulk_window(std::false_type /*detected*/)
-{
-    return false;
-}
-
 /*!
@brief lexical analysis

@@ -221,20 +184,9 @@ class lexer : public lexer_base<BasicJsonType>
    /// whether the last read token can be reconstructed from the input adapter
    /// on demand (in error paths) instead of being copied on every scanned
    /// character; see input_adapter_supports_seek
-    static constexpr bool seekable =
+    static constexpr bool lazy_token_string =
        input_adapter_supports_seek<InputAdapterType>(is_detected<detect_supports_seek, InputAdapterType> {});

-    /// whether the adapter keeps the token itself (mark_token_start() /
-    /// copy_token()); see input_adapter_supports_token_tracking
-    static constexpr bool adapter_token =
-        !seekable && input_adapter_supports_token_tracking<InputAdapterType>(is_detected<detect_supports_token_tracking, InputAdapterType> {});
-
-    /// whether the last read token is obtained from the input adapter on
-    /// demand (in error paths) instead of being copied on every scanned
-    /// character: seekable adapters reconstruct it from the consumed input,
-    /// token-tracking adapters keep it themselves
-    static constexpr bool lazy_token_string = seekable || adapter_token;
-
    /// whether the read position is derived from the input adapter on demand
    /// instead of being counted on every scanned character. Seekable adapters
    /// know how much input they consumed and can revisit it, so
@@ -242,7 +194,7 @@ class lexer : public lexer_base<BasicJsonType>
    /// and line and column are recomputed from the consumed input only when
    /// get_position() is called (errors). Counting per character kept two
    /// increments and a newline check in the hot path of every get().
-    static constexpr bool lazy_position = seekable;
+    static constexpr bool lazy_position = lazy_token_string;

    /// whether a simulated unget can be passed on to the input adapter, which
    /// then leaves the character in the input; see
@@ -251,17 +203,14 @@ class lexer : public lexer_base<BasicJsonType>
        input_adapter_supports_lookahead<InputAdapterType>(is_detected<detect_supports_lookahead, InputAdapterType> {});

    /// whether string scanning may bulk-consume runs of ordinary characters
-    /// directly from a contiguous input buffer (SWAR fast path). Without
-    /// lazy_token_string / lazy_position, the bulk paths copy the consumed
-    /// characters into token_string and advance the position counters
-    /// themselves (see bulk_consume).
+    /// directly from a contiguous input buffer (SWAR fast path). This requires
+    /// the token to be reconstructible lazily (lazy_token_string), so bypassing
+    /// the per-character capture in get() cannot lose error diagnostics. It
+    /// also implies lazy_position, so the bulk paths need not advance the
+    /// position counters.
    static constexpr bool bulk_scan =
-        input_adapter_supports_bulk_scan<InputAdapterType>(is_detected<detect_supports_bulk_scan, InputAdapterType> {});
-
-    /// whether the contiguous block is only a window into the input, so that
-    /// its end does not end a token; see input_adapter_bulk_window
-    static constexpr bool bulk_window =
-        input_adapter_bulk_window<InputAdapterType>(is_detected<detect_bulk_window, InputAdapterType> {});
+        lazy_token_string
+        && input_adapter_supports_bulk_scan<InputAdapterType>(is_detected<detect_supports_bulk_scan, InputAdapterType> {});

  public:
    using token_type = typename lexer_base<BasicJsonType>::token_type;
@@ -270,11 +219,7 @@ class lexer : public lexer_base<BasicJsonType>
        : ia(std::move(adapter))
        , ignore_comments(ignore_comments_)
        , discard_number_values(discard_number_values_)
-    {
-        // the token string of an error before the first token is everything
-        // read so far
-        begin_token(std::integral_constant<bool, adapter_token> {});
-    }
+    {}

    // deleted because of pointer members
    lexer(const lexer&) = delete;
@@ -291,8 +236,8 @@ class lexer : public lexer_base<BasicJsonType>
    /// contiguous input: try to decode the 4 hex digits following `\\u`
    /// directly from the input buffer via hex_codepoint(), instead of 4 calls
    /// to get(). On success, advances the adapter exactly as those 4 get()
-    /// calls would (including the position and token bookkeeping of a
-    /// streaming adapter, see bulk_consume) and leaves @a current holding the last of
+    /// calls would (bulk_scan implies lazy_position, so there are no position
+    /// counters to advance) and leaves @a current holding the last of
    /// the 4 digits, just as the last such get() would; the codepoint is
    /// written to @a out. Makes no state change and returns false for a
    /// pending unget, fewer than 4 remaining bytes, or any of the 4 bytes not
@@ -311,7 +256,7 @@ class lexer : public lexer_base<BasicJsonType>
        {
            return false;
        }
-        bulk_consume(reinterpret_cast<const char*>(raw), 4);
+        ia.bulk_skip(4);
        current = char_traits<char_type>::to_int_type(raw[3]);
        out = codepoint;
        return true;
@@ -440,36 +385,7 @@ class lexer : public lexer_base<BasicJsonType>
            return;
        }
        token_buffer.append(reinterpret_cast<const typename string_t::value_type*>(data), pos);
-        bulk_consume(reinterpret_cast<const char*>(data), pos);
-    }
-
-    /// consume @a n characters at @a data (the adapter's bulk_data()) and do
-    /// the bookkeeping get() would have done for them; the characters are
-    /// never newlines
-    void bulk_consume(const char* data, std::size_t n)
-    {
-        bulk_track_position(n, std::integral_constant<bool, lazy_position> {});
-        bulk_track_token(data, n, std::integral_constant<bool, lazy_token_string> {});
-        ia.bulk_skip(n);
-    }
-
-    /// seekable adapter: the position is derived from the adapter
-    void bulk_track_position(std::size_t /*n*/, std::true_type /*lazy*/) const noexcept {}
-
-    /// streaming adapter: count the characters
-    void bulk_track_position(std::size_t n, std::false_type /*lazy*/) noexcept
-    {
-        position.chars_read_total += n;
-        position.chars_read_current_line += n;
-    }
-
-    /// the token is obtained from the adapter
-    void bulk_track_token(const char* /*data*/, std::size_t /*n*/, std::true_type /*lazy*/) const noexcept {}
-
-    /// streaming adapter: capture the characters
-    void bulk_track_token(const char* data, std::size_t n, std::false_type /*lazy*/)
-    {
-        token_string.insert(token_string.end(), data, data + n);
+        ia.bulk_skip(pos);
    }

    /// streaming input: no bulk fast path
@@ -1687,10 +1603,6 @@ scan_number_done:
            }
        }
        const std::size_t len = i;
-        if (number_may_continue(len == avail, std::integral_constant<bool, bulk_window> {}))
-        {
-            return token_type::uninitialized;
-        }

        // reset() records where this token starts (for diagnostics), so it has
        // to run before the input position advances below
@@ -1708,8 +1620,7 @@ scan_number_done:
            const token_type integer_result = convert_integer(number_type, data, data + len);
            if (JSON_HEDLEY_LIKELY(integer_result != token_type::uninitialized))
            {
-                bulk_consume(data + 1, len - 1);
-                read_number_terminator(std::integral_constant<bool, bulk_window> {});
+                ia.bulk_skip(len - 1);
                return integer_result;
            }
            // The value does not fit an integer, so this token converts as a
@@ -1725,37 +1636,11 @@ scan_number_done:
        token_buffer.append(reinterpret_cast<const typename string_t::value_type*>(data), len);
        decimal_point_position = dot_index;

-        bulk_consume(data + 1, len - 1);
-        read_number_terminator(std::integral_constant<bool, bulk_window> {});
+        ia.bulk_skip(len - 1);

        return convert_number(number_type, mantissa_end);
    }

-    /// window adapter: a number that reaches the end of the window may continue
-    /// after it, so scan_number() has to read it character by character
-    static constexpr bool number_may_continue(bool at_end, std::true_type /*window*/) noexcept
-    {
-        return at_end;
-    }
-
-    /// the end of the block is the end of the input, which ends the number
-    static constexpr bool number_may_continue(bool /*at_end*/, std::false_type /*window*/) noexcept
-    {
-        return false;
-    }
-
-    /// window adapter: read the character after a bulk-scanned number and unget
-    /// it, as scan_number() does. The adapter is a stream that is handed back to
-    /// the user, who must find the same input consumed either way.
-    void read_number_terminator(std::true_type /*window*/)
-    {
-        get();
-        unget();
-    }
-
-    /// the input is not handed back, so the terminator can stay unread
-    void read_number_terminator(std::false_type /*window*/) const noexcept {}
-
    /// contiguous input: try the number fast path, else the byte-path scanner
    token_type scan_number_dispatch(std::true_type /*bulk*/)
    {
@@ -1811,30 +1696,11 @@ scan_number_done:
    /// seekable adapter: remember where the current token starts so it can be
    /// reconstructed from the input on error; current has already been
    /// consumed, hence the -1
-    void note_token_start(std::true_type /*lazy*/)
-    {
-        note_token_start_lazy(std::integral_constant<bool, adapter_token> {});
-    }
-
-    void note_token_start_lazy(std::false_type /*adapter_token*/) noexcept
+    void note_token_start(std::true_type /*lazy*/) noexcept
    {
        token_string_start = ia.get_consumed_count() - 1;
    }

-    /// token-tracking adapter: start tracking the token at the first character
-    void begin_token(std::true_type /*adapter_token*/) noexcept
-    {
-        ia.begin_token();
-    }
-
-    void begin_token(std::false_type /*adapter_token*/) const noexcept {}
-
-    /// token-tracking adapter: the token starts with the current character
-    void note_token_start_lazy(std::true_type /*adapter_token*/)
-    {
-        ia.mark_token_start(current);
-    }
-
    /// streaming adapter: start copying the token eagerly, beginning with the
    /// already-read first character
    void note_token_start(std::false_type /*lazy*/) noexcept
@@ -2155,20 +2021,6 @@ scan_number_done:
  public:
    /// seekable adapter: rebuild the last read token from the input on demand
    const std::vector<char_type>& collect_token_chars(std::vector<char_type>& out, std::true_type /*lazy*/) const
-    {
-        return collect_token_chars_lazy(out, std::integral_constant<bool, adapter_token> {});
-    }
-
-    /// token-tracking adapter: the adapter hands out everything read since
-    /// mark_token_start(), except a pending unget (see below)
-    const std::vector<char_type>& collect_token_chars_lazy(std::vector<char_type>& out, std::true_type /*adapter_token*/) const
-    {
-        const bool pending_real_unget = next_unget && current != char_traits<char_type>::eof();
-        ia.copy_token(out, pending_real_unget);
-        return out;
-    }
-
-    const std::vector<char_type>& collect_token_chars_lazy(std::vector<char_type>& out, std::false_type /*adapter_token*/) const
    {
        // a pending unget of a real (non-EOF) character means that character
        // was consumed from the input but is not part of the token; EOF is
@@ -2290,8 +2142,9 @@ scan_number_done:
    Pretty-printed JSON indents every line with a run of spaces, which the loop
    in skip_whitespace() would otherwise read one character at a time. The
    spaces are skipped 8 bytes at a time; the last 7 bytes of the input and any
-    other whitespace are left to that loop. Skipping bypasses get();
-    bulk_consume() does its bookkeeping.
+    other whitespace are left to that loop. Skipping bypasses get(), which is
+    fine because bulk_scan implies lazy_position: the position is derived from
+    the adapter, not counted per character.
    */
    void skip_indentation(std::true_type /*bulk*/)
    {
@@ -2314,7 +2167,7 @@ scan_number_done:
                break;
            }
        }
-        bulk_consume(data, pos);
+        ia.bulk_skip(pos);
    }

    /// streaming input: no bulk fast path
@@ -532,7 +532,7 @@ class json_pointer
            {}
        };

-        std::vector<slot> table;
+        std::vector<slot> slots;
        std::size_t used = 0;

        static std::size_t hash_of(std::size_t parent, const string_t& token) noexcept
@@ -547,19 +547,19 @@ class json_pointer

        void grow()
        {
-            std::vector<slot> old(table.size() * 2);
-            old.swap(table);
-            const std::size_t mask = table.size() - 1;
+            std::vector<slot> old(slots.size() * 2);
+            old.swap(slots);
+            const std::size_t mask = slots.size() - 1;
            for (const auto& s : old)
            {
                if (s.token != nullptr)
                {
                    std::size_t i = s.hash & mask;
-                    while (table[i].token != nullptr)
+                    while (slots[i].token != nullptr)
                    {
                        i = (i + 1) & mask;
                    }
-                    table[i] = s;
+                    slots[i] = s;
                }
            }
        }
@@ -572,7 +572,7 @@ class json_pointer

        // start with the empty prefix only
        prefix_tree()
-            : table(16)
+            : slots(16)
            , parent(1, 0)
            , is_array(1, false)
        {}
@@ -582,20 +582,20 @@ class json_pointer
        std::size_t add_child(std::size_t id, const string_t& reference_token)
        {
            const std::size_t hash = hash_of(id, reference_token);
-            const std::size_t mask = table.size() - 1;
+            const std::size_t mask = slots.size() - 1;
            std::size_t i = hash & mask;
-            while (table[i].token != nullptr)
+            while (slots[i].token != nullptr)
            {
-                if (table[i].hash == hash && table[i].parent == id && *table[i].token == reference_token)
+                if (slots[i].hash == hash && slots[i].parent == id && *slots[i].token == reference_token)
                {
-                    return table[i].id;
+                    return slots[i].id;
                }
                i = (i + 1) & mask;
            }

            // new prefix
            const std::size_t child = parent.size();
-            table[i] = slot(hash, id, &reference_token, child);
+            slots[i] = slot(hash, id, &reference_token, child);
            if (reference_token == "0")
            {
                is_array[id] = true;
@@ -604,7 +604,7 @@ class json_pointer
            is_array.push_back(false);

            // keep the load factor below 1/2
-            if (++used * 2 > table.size())
+            if (++used * 2 > slots.size())
            {
                grow();
            }
@@ -19,7 +19,8 @@
 #undef NLOHMANN_CAN_CALL_STD_FUNC_IMPL
 #undef JSON_INLINE_VARIABLE
 #undef JSON_NO_UNIQUE_ADDRESS
-#undef JSON_UNLOCKED_FILE_IO
+#undef JSON_DISABLE_ENUM_SERIALIZATION
+#undef JSON_DISABLE_TUPLE_REFERENCE_CONVERSION
 #undef JSON_DTOA_SSE2
 #undef JSON_DTOA_NEON

@@ -46,10 +47,6 @@
    #undef JSON_STRICT_BINARY_UTF8
    #undef JSON_DELETE_DEPRECATED_FUNCTIONS
    #undef JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS
-    #undef JSON_DISABLE_ENUM_SERIALIZATION
-    #undef JSON_DISABLE_TUPLE_REFERENCE_CONVERSION
-    #undef JSON_DISABLE_STREAM_BULK_SCAN
-    #undef JSON_DISABLE_UNLOCKED_FILE_IO
 #endif

 #include <nlohmann/thirdparty/hedley/hedley_undef.hpp>
@@ -23,7 +23,6 @@
    #include <cstdlib> // _byteswap_ushort, _byteswap_ulong, _byteswap_uint64
 #endif

-#include <nlohmann/detail/bit_ops.hpp>
 #include <nlohmann/detail/input/binary_reader.hpp>
 #include <nlohmann/detail/input/string_scan.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
@@ -205,12 +204,24 @@ class binary_writer
            }

            case value_t::number_integer:
+            {
+                if (j.m_data.m_value.number_integer >= 0)
+                {
+                    // CBOR does not differentiate between positive signed
+                    // integers and unsigned integers
+                    write_cbor_head(0x00, static_cast<std::uint64_t>(j.m_data.m_value.number_integer));
+                }
+                else
+                {
+                    // a negative integer n is encoded as -1 - n
+                    write_cbor_head(0x20, static_cast<std::uint64_t>(-1 - j.m_data.m_value.number_integer));
+                }
+                break;
+            }
+
            case value_t::number_unsigned:
            {
-                // one case for both, so that an array mixing negative
-                // (number_integer) and non-negative (number_unsigned) values
-                // does not mispredict the switch
-                write_cbor_integer(j, std::integral_constant<bool, integers_fit_64_bits()>());
+                write_cbor_head(0x00, conditional_static_cast<std::uint64_t>(j.m_data.m_value.number_unsigned));
                break;
            }

@@ -245,7 +256,13 @@ class binary_writer

            case value_t::array:
            {
-                write_cbor_array(j, depth);
+                // step 1: write control byte and the array size
+                write_cbor_head(0x80, j.m_data.m_value.array->size());
+
+                for (const auto& el : *j.m_data.m_value.array)
+                {
+                    write_cbor(el, depth + 1);
+                }
                break;
            }

@@ -403,12 +420,54 @@ class binary_writer
            }

            case value_t::number_integer:
+            {
+                if (j.m_data.m_value.number_integer >= 0)
+                {
+                    // MessagePack does not differentiate between positive
+                    // signed integers and unsigned integers.
+                    write_msgpack_unsigned(static_cast<std::uint64_t>(j.m_data.m_value.number_integer));
+                }
+                else
+                {
+                    if (j.m_data.m_value.number_integer >= -32)
+                    {
+                        // negative fixnum
+                        write_number(static_cast<std::int8_t>(j.m_data.m_value.number_integer));
+                    }
+                    else if (j.m_data.m_value.number_integer >= (std::numeric_limits<std::int8_t>::min)() &&
+                             j.m_data.m_value.number_integer <= (std::numeric_limits<std::int8_t>::max)())
+                    {
+                        // int 8
+                        oa.write_character(to_char_type(0xD0));
+                        write_number(static_cast<std::int8_t>(j.m_data.m_value.number_integer));
+                    }
+                    else if (j.m_data.m_value.number_integer >= (std::numeric_limits<std::int16_t>::min)() &&
+                             j.m_data.m_value.number_integer <= (std::numeric_limits<std::int16_t>::max)())
+                    {
+                        // int 16
+                        oa.write_character(to_char_type(0xD1));
+                        write_number(static_cast<std::int16_t>(j.m_data.m_value.number_integer));
+                    }
+                    else if (j.m_data.m_value.number_integer >= (std::numeric_limits<std::int32_t>::min)() &&
+                             j.m_data.m_value.number_integer <= (std::numeric_limits<std::int32_t>::max)())
+                    {
+                        // int 32
+                        oa.write_character(to_char_type(0xD2));
+                        write_number(static_cast<std::int32_t>(j.m_data.m_value.number_integer));
+                    }
+                    else
+                    {
+                        // int 64
+                        oa.write_character(to_char_type(0xD3));
+                        write_number(static_cast<std::int64_t>(j.m_data.m_value.number_integer));
+                    }
+                }
+                break;
+            }
+
            case value_t::number_unsigned:
            {
-                // one case for both, so that an array mixing negative
-                // (number_integer) and non-negative (number_unsigned) values
-                // does not mispredict the switch
-                write_msgpack_integer(j, std::integral_constant<bool, integers_fit_64_bits()>());
+                write_msgpack_unsigned(static_cast<std::uint64_t>(j.m_data.m_value.number_unsigned));
                break;
            }

@@ -426,7 +485,13 @@ class binary_writer

            case value_t::array:
            {
-                write_msgpack_array(j, depth);
+                // step 1: write control byte and the array size
+                write_msgpack_array_prefix(j.m_data.m_value.array->size(), j);
+
+                for (const auto& el : *j.m_data.m_value.array)
+                {
+                    write_msgpack(el, depth + 1);
+                }
                break;
            }

@@ -759,142 +824,6 @@ class binary_writer
        JSON_THROW(type_error::create(exception_id::discarded_value_used, concat("cannot serialize discarded value to ", format_name), &j));
    }

-    /// how the range of integer type @a NumberType relates to that of @a TargetType
-    template<typename TargetType, typename NumberType>
-    struct integer_range
-    {
-        /// whether NumberType can hold values above the maximum of TargetType
-        static constexpr bool may_exceed_max = std::numeric_limits<NumberType>::digits > std::numeric_limits<TargetType>::digits;
-        /// whether NumberType can hold values below the minimum of TargetType
-        static constexpr bool may_fall_below_min = std::numeric_limits<NumberType>::is_signed
-            && (!std::numeric_limits<TargetType>::is_signed || may_exceed_max);
-    };
-
-    /*!
-    @brief whether integer @a n does not exceed the maximum of @a TargetType
-
-    The binary formats store integers in at most 64 bits, but number_integer_t
-    and number_unsigned_t may be wider (e.g., __int128). The range of the
-    integer is taken from std::numeric_limits, so a number type whose range
-    fits into @a TargetType is never checked: the function is then constant
-    true, and the default int64_t/uint64_t types pay nothing.
-    */
-    template<typename TargetType, typename NumberType>
-    static constexpr bool integer_fits_max(const NumberType n) noexcept
-    {
-        return integer_fits_max<TargetType>(n, std::integral_constant<bool, integer_range<TargetType, NumberType>::may_exceed_max>());
-    }
-
-    template<typename TargetType, typename NumberType>
-    static constexpr bool integer_fits_max(const NumberType /*unused*/, std::false_type /*may_exceed*/) noexcept
-    {
-        return true;
-    }
-
-    template<typename TargetType, typename NumberType>
-    static constexpr bool integer_fits_max(const NumberType n, std::true_type /*may_exceed*/) noexcept
-    {
-        // NumberType has more digits than TargetType, so it can hold its maximum
-        return n <= static_cast<NumberType>((std::numeric_limits<TargetType>::max)());
-    }
-
-    /*!
-    @brief whether integer @a n is not below the minimum of @a TargetType;
-           constant true if NumberType cannot hold such a value
-    */
-    template<typename TargetType, typename NumberType>
-    static constexpr bool integer_fits_min(const NumberType n) noexcept
-    {
-        return integer_fits_min<TargetType>(n, std::integral_constant<bool, integer_range<TargetType, NumberType>::may_fall_below_min>());
-    }
-
-    template<typename TargetType, typename NumberType>
-    static constexpr bool integer_fits_min(const NumberType /*unused*/, std::false_type /*may_fall_below*/) noexcept
-    {
-        return true;
-    }
-
-    template<typename TargetType, typename NumberType>
-    static constexpr bool integer_fits_min(const NumberType n, std::true_type /*may_fall_below*/) noexcept
-    {
-        // NumberType is signed and either TargetType is unsigned (minimum 0)
-        // or NumberType has more digits, so it can hold the minimum
-        return n >= static_cast<NumberType>((std::numeric_limits<TargetType>::min)());
-    }
-
-    /*!
-    @brief whether integer @a n lies in the range of @a TargetType
-    */
-    template<typename TargetType, typename NumberType>
-    static constexpr bool integer_fits(const NumberType n) noexcept
-    {
-        return integer_fits_min<TargetType>(n) && integer_fits_max<TargetType>(n);
-    }
-
-    /*!
-    @brief the decimal digits of the non-negative integer @a n
-    */
-    template<typename NumberType>
-    static std::string integer_to_string(NumberType n, std::false_type /*is_signed*/)
-    {
-        std::string result;
-        do
-        {
-            result.push_back(static_cast<char>('0' + (n % 10)));
-            n = static_cast<NumberType>(n / 10);
-        }
-        while (n != 0);
-        std::reverse(result.begin(), result.end());
-        return result;
-    }
-
-    /*!
-    @brief the decimal digits of the integer @a n, with a leading '-' if it
-           is negative
-    */
-    template<typename NumberType>
-    static std::string integer_to_string(NumberType n, std::true_type /*is_signed*/)
-    {
-        // the remainder of a negative n is not positive; each digit is
-        // negated on its own, because negating the minimum of NumberType
-        // as a whole would overflow
-        const bool negative = n < 0;
-        std::string result;
-        do
-        {
-            const auto remainder = n % 10;
-            result.push_back(static_cast<char>('0' + (remainder < 0 ? -remainder : remainder)));
-            n = static_cast<NumberType>(n / 10);
-        }
-        while (n != 0);
-        if (negative)
-        {
-            result.push_back('-');
-        }
-        std::reverse(result.begin(), result.end());
-        return result;
-    }
-
-    /*!
-    @brief throws because the integer @a j is too large for @a format_name
-    @throw out_of_range.407 always
-    */
-    JSON_HEDLEY_NO_RETURN static void throw_integer_out_of_range(const BasicJsonType& j, const char* format_name, const char* range)
-    {
-        // neither std::to_string(), which has no overload for integer types
-        // wider than 64 bits, nor dump(), which would also instantiate the
-        // serializer for objects and fail for key types it cannot write
-        using integer_limits = std::numeric_limits<typename BasicJsonType::number_integer_t>;
-        using unsigned_limits = std::numeric_limits<typename BasicJsonType::number_unsigned_t>;
-        const std::string number = j.is_number_unsigned()
-                                   ? integer_to_string(j.m_data.m_value.number_unsigned, std::integral_constant<bool, unsigned_limits::is_signed>())
-                                   : integer_to_string(j.m_data.m_value.number_integer, std::integral_constant<bool, integer_limits::is_signed>());
-        static_cast<void>(number); // unused when JSON_NOEXCEPTION is defined
-        static_cast<void>(format_name);
-        static_cast<void>(range);
-        JSON_THROW(out_of_range::create(exception_id::integer_too_large, concat("integer number ", number, " cannot be represented by ", format_name, " as it does not fit ", range), &j));
-    }
-
    void write_msgpack_array_prefix(const std::size_t N, const BasicJsonType& j)
    {
        const auto n = to_msgpack_length(N, j);
@@ -1651,8 +1580,6 @@ class binary_writer
            is neither an object nor an array
    @throw out_of_range.415 if @a j is binary with a subtype that does not fit
           into a byte, before anything is written
-    @throw out_of_range.407 if @a j is an integer that does not fit the 64 bits
-           of a BSON integer, before anything is written
    @throw type_error.316 if @a j is a string that is not valid UTF-8, before
           anything is written
    @throw type_error.321 if @a j is discarded
@@ -1671,17 +1598,9 @@ class binary_writer
                return 8ul;

            case value_t::number_integer:
-                if (JSON_HEDLEY_UNLIKELY(!integer_fits<std::int64_t>(j.m_data.m_value.number_integer)))
-                {
-                    throw_integer_out_of_range(j, "BSON", "int64");
-                }
-                return calc_bson_integer_size(static_cast<std::int64_t>(j.m_data.m_value.number_integer));
+                return calc_bson_integer_size(j.m_data.m_value.number_integer);

            case value_t::number_unsigned:
-                if (JSON_HEDLEY_UNLIKELY(!integer_fits_max<std::uint64_t>(j.m_data.m_value.number_unsigned)))
-                {
-                    throw_integer_out_of_range(j, "BSON", "uint64");
-                }
                return calc_bson_unsigned_size(conditional_static_cast<std::uint64_t>(j.m_data.m_value.number_unsigned));

            case value_t::string:
@@ -1720,9 +1639,8 @@ class binary_writer
            case value_t::number_float:
                return write_bson_double(name, j.m_data.m_value.number_float);

-            // calc_bson_value_size() checked that integers fit 64 bits
            case value_t::number_integer:
-                return write_bson_integer(name, static_cast<std::int64_t>(j.m_data.m_value.number_integer));
+                return write_bson_integer(name, j.m_data.m_value.number_integer);

            case value_t::number_unsigned:
                return write_bson_unsigned(name, conditional_static_cast<std::uint64_t>(j.m_data.m_value.number_unsigned));
@@ -2033,376 +1951,6 @@ class binary_writer
        }
    }

-    /*!
-    @brief size class of an unsigned integer from its bit length
-
-    1, 2, 3, or 4 if @a x fits 1, 2, 4, or 8 bytes. Looked up from the number
-    of leading zero bits instead of found by branches: the sizes of a stream
-    of numbers are hard to predict, and a mispredicted branch costs more than
-    writing the number. (A table, as comparisons are vectorized by clang into
-    slower code.)
-    */
-    static unsigned integer_size_class(const std::uint64_t x) noexcept
-    {
-        static constexpr std::array<std::uint8_t, 64> size_class_by_leading_zeros =
-        {
-            {
-                4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
-                3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
-                2, 2, 2, 2, 2, 2, 2, 2,
-                1, 1, 1, 1, 1, 1, 1, 1
-            }
-        };
-        // x | 1 keeps count_leading_zeros() away from 0
-        return size_class_by_leading_zeros[static_cast<std::size_t>(count_leading_zeros(x | 1u))];
-    }
-
-    /*!
-    @brief encode @a first_byte and the low-order bytes of @a value that
-           @a size_class calls for (none, or 1, 2, 4, or 8) in network order
-           to @a out
-    @return the number of characters of the encoding; up to
-            @ref integer_encoding_space characters at @a out are overwritten
-
-    The bytes are written as one byte and one 8-byte word whose bytes after
-    the value are scratch that the caller drops, so that writing them does not
-    depend on the size class. For class 0 the word is all scratch; it is
-    shifted by 60 bits rather than 64, which would be undefined.
-    */
-    std::size_t encode_first_byte_and_tail(CharType* out, const std::uint8_t first_byte, const unsigned size_class, const std::uint64_t value) const noexcept
-    {
-        out[0] = to_char_type(first_byte);
-        const unsigned unused_bits = 64u - ((8u << size_class) >> 1u);
-        const std::uint64_t tail = is_little_endian ? byte_swap(value) >> unused_bits : value << unused_bits;
-        std::memcpy(out + 1, &tail, sizeof(tail));
-        return ((std::size_t{1} << size_class) >> 1u) + 1;
-    }
-
-    /// characters encode_first_byte_and_tail() may overwrite: the first byte
-    /// and one 8-byte word
-    static constexpr std::size_t integer_encoding_space = 9;
-
-    /*!
-    @brief the 64 bits of a number_integer or number_unsigned value, and a mask
-           that is all ones if it is negative, else zero
-
-    Selected through masks rather than branches, as the type and the sign of
-    the values in an array of mixed signs alternate unpredictably (non-negative
-    integers are number_unsigned after parsing). Up to 64 bits, the sign is bit
-    63 of the result (a narrower integer is sign-extended); computing it with
-    masks keeps GCC from branching on the type. A wider integer has to be
-    compared.
-    */
-    static std::uint64_t integer_bits(const BasicJsonType& j, std::uint64_t& sign_mask) noexcept
-    {
-        const bool is_signed = j.m_data.m_type == value_t::number_integer;
-        const std::uint64_t raw = is_signed
-                                  ? static_cast<std::uint64_t>(j.m_data.m_value.number_integer)
-                                  : static_cast<std::uint64_t>(j.m_data.m_value.number_unsigned);
-        sign_mask = sizeof(typename BasicJsonType::number_integer_t) <= sizeof(std::uint64_t)
-                    ? (std::uint64_t{0} - static_cast<std::uint64_t>(is_signed)) & (std::uint64_t{0} - (raw >> 63u))
-                    : std::uint64_t{0} - static_cast<std::uint64_t>(is_signed && j.m_data.m_value.number_integer < 0);
-        return raw;
-    }
-
-    /*!
-    @brief encode the head of a CBOR integer to @a out without branching on its
-           size
-    @return the number of characters of the head
-
-    Same output as @ref write_cbor_head. The lengths of strings and containers
-    are mostly predictable, so their heads keep the branches; the sizes of a
-    run of integers are not, so an integer's head is assembled without them.
-    */
-    std::size_t encode_cbor_integer_head(CharType* out, const std::uint8_t major_type, const std::uint64_t argument) const noexcept
-    {
-        // an argument of at most 23 is in size class 1 (one byte) and is moved
-        // to class 0, the first byte, by subtracting 1
-        const auto is_immediate = static_cast<unsigned>(argument <= 0x17u);
-        const unsigned size_class = integer_size_class(argument) - is_immediate;
-
-        // the first byte: the argument itself if it is immediate, else
-        // 0x17 + size_class, selected through a mask
-        const std::uint64_t immediate_mask = std::uint64_t{0} - is_immediate;
-        const auto first_byte = static_cast<std::uint8_t>(major_type + ((argument & immediate_mask) | ((0x17u + size_class) & ~immediate_mask)));
-        return encode_first_byte_and_tail(out, first_byte, size_class, argument);
-    }
-
-    /*!
-    @brief write an array value (head and elements) as CBOR
-
-    Integer elements, the most common scalar, are written without a call to
-    @ref write_cbor. The loop is kept out of line: inlined into write_cbor, its
-    registers would be saved and restored on every call of write_cbor, which
-    is one call per value nested in an object.
-    */
-    JSON_HEDLEY_NEVER_INLINE
-    void write_cbor_array(const BasicJsonType& j, const std::size_t depth)
-    {
-        write_cbor_head(0x80, j.m_data.m_value.array->size());
-        write_cbor_array_elements(j, depth, std::integral_constant<bool, integers_fit_64_bits()>());
-    }
-
-    void write_cbor_array_elements(const BasicJsonType& j, const std::size_t depth, std::true_type /*fits_64_bits*/)
-    {
-        write_array_elements(j, [this](CharType * out, const BasicJsonType & el)
-        {
-            return encode_cbor_integer(out, el);
-        }, [this, depth](const BasicJsonType & el)
-        {
-            write_cbor(el, depth + 1);
-        });
-    }
-
-    void write_cbor_array_elements(const BasicJsonType& j, const std::size_t depth, std::false_type /*fits_64_bits*/)
-    {
-        for (const auto& el : *j.m_data.m_value.array)
-        {
-            write_cbor(el, depth + 1);
-        }
-    }
-
-    /*!
-    @brief write the elements of the array @a j, runs of integers with
-           @a encode_integer and all other values with @a write_value
-
-    Runs of integers are encoded straight into space reserved from the sink
-    for a whole run: the write pointer stays a local, where it would otherwise
-    be reloaded from the sink for every value, as a store of a character may
-    alias it.
-    */
-    template<typename EncodeInteger, typename WriteValue>
-    void write_array_elements(const BasicJsonType& j, EncodeInteger encode_integer, WriteValue write_value)
-    {
-        constexpr std::size_t max_run = max_reserve_size / integer_encoding_space;
-        auto it = j.m_data.m_value.array->begin();
-        const auto end = j.m_data.m_value.array->end();
-        while (it != end)
-        {
-            if (it->is_number_integer())
-            {
-                CharType* const start = oa.reserve(max_run * integer_encoding_space);
-                CharType* out = start;
-                for (std::size_t n = 0; n < max_run && it != end && it->is_number_integer(); ++n, ++it)
-                {
-                    out += encode_integer(out, *it);
-                }
-                oa.commit(static_cast<std::size_t>(out - start));
-            }
-            else
-            {
-                write_value(*it);
-                ++it;
-            }
-        }
-    }
-
-    /*!
-    @brief write a number_integer or number_unsigned value as a CBOR integer
-
-    A negative integer n has major type 1 and the argument -1 - n, which is ~n.
-    Kept out of line, like the other per-value paths, so that write_cbor stays
-    small (runs of integers in an array are encoded inline instead).
-    */
-    JSON_HEDLEY_NEVER_INLINE
-    void write_cbor_integer(const BasicJsonType& j, std::true_type /*fits_64_bits*/)
-    {
-        oa.commit(encode_cbor_integer(oa.reserve(integer_encoding_space), j));
-    }
-
-    /// write a number_integer or number_unsigned value of a number type wider
-    /// than 64 bits as a CBOR integer, with range checks on the whole value
-    void write_cbor_integer(const BasicJsonType& j, std::false_type /*fits_64_bits*/)
-    {
-        if (j.m_data.m_type == value_t::number_unsigned)
-        {
-            if (JSON_HEDLEY_UNLIKELY(!integer_fits_max<std::uint64_t>(j.m_data.m_value.number_unsigned)))
-            {
-                throw_integer_out_of_range(j, "CBOR", "uint64");
-            }
-            write_cbor_head(0x00, conditional_static_cast<std::uint64_t>(j.m_data.m_value.number_unsigned));
-            return;
-        }
-
-        if (j.m_data.m_value.number_integer >= 0)
-        {
-            if (JSON_HEDLEY_UNLIKELY(!integer_fits_max<std::uint64_t>(j.m_data.m_value.number_integer)))
-            {
-                throw_integer_out_of_range(j, "CBOR", "[-2^64, 2^64-1]");
-            }
-            // CBOR does not differentiate between positive signed
-            // integers and unsigned integers
-            write_cbor_head(0x00, static_cast<std::uint64_t>(j.m_data.m_value.number_integer));
-        }
-        else
-        {
-            // a negative integer n is encoded as -1 - n
-            if (JSON_HEDLEY_UNLIKELY(!integer_fits_max<std::uint64_t>(-1 - j.m_data.m_value.number_integer)))
-            {
-                throw_integer_out_of_range(j, "CBOR", "[-2^64, 2^64-1]");
-            }
-            write_cbor_head(0x20, static_cast<std::uint64_t>(-1 - j.m_data.m_value.number_integer));
-        }
-    }
-
-    /// encode a number_integer or number_unsigned value to @a out (see
-    /// @ref write_cbor_integer) and return the number of characters
-    std::size_t encode_cbor_integer(CharType* out, const BasicJsonType& j) const noexcept
-    {
-        std::uint64_t sign_mask = 0;
-        const std::uint64_t raw = integer_bits(j, sign_mask);
-        // ~raw is -1 - n in the 64 bits that are written
-        return encode_cbor_integer_head(out, static_cast<std::uint8_t>(sign_mask & 0x20u), raw ^ sign_mask);
-    }
-
-    /*!
-    @brief whether the CBOR and MessagePack integers of BasicJsonType are
-           written by @ref encode_cbor_integer and @ref encode_msgpack_integer
-
-    These pick the format from the low 64 bits; a wider number type is written
-    with range checks on the whole value instead.
-    */
-    static constexpr bool integers_fit_64_bits() noexcept
-    {
-        return sizeof(typename BasicJsonType::number_integer_t) <= sizeof(std::uint64_t)
-               && sizeof(typename BasicJsonType::number_unsigned_t) <= sizeof(std::uint64_t);
-    }
-
-    /*!
-    @brief write a number_integer or number_unsigned value as a MessagePack
-           integer without branching on its sign or size
-
-    Same output as @ref write_msgpack: a non-negative integer as positive fixint
-    (< 128) or uint 8/16/32/64, a negative one as negative fixint (>= -32) or
-    int 8/16/32/64. Kept out of line (see @ref write_cbor_integer).
-    */
-    JSON_HEDLEY_NEVER_INLINE
-    void write_msgpack_integer(const BasicJsonType& j, std::true_type /*fits_64_bits*/)
-    {
-        oa.commit(encode_msgpack_integer(oa.reserve(integer_encoding_space), j));
-    }
-
-    /// encode a number_integer or number_unsigned value to @a out (see
-    /// @ref write_msgpack_integer) and return the number of characters
-    std::size_t encode_msgpack_integer(CharType* out, const BasicJsonType& j) const noexcept
-    {
-        std::uint64_t sign_mask = 0;
-        const std::uint64_t raw = integer_bits(j, sign_mask);
-
-        // A negative n fits int 8/16/32 exactly if 2 * (-1 - n) + 1 fits
-        // uint 8/16/32, so x gives the size class of either sign.
-        const std::uint64_t is_negative = sign_mask & 1u;
-        const std::uint64_t x = ((raw ^ sign_mask) << is_negative) | is_negative;
-
-        // A fixint is at most 127, or at least -32 (x at most 63). It is in
-        // size class 1 and is moved to class 0, the first byte, by subtracting 1.
-        const auto is_fixint = static_cast<unsigned>(x <= (127u ^ (sign_mask & 64u)));
-        const unsigned size_class = integer_size_class(x) - is_fixint;
-
-        // the first byte: the low byte of the integer for a fixint, else the
-        // marker 0xCC..0xCF (uint) or 0xD0..0xD3 (int), selected through a mask
-        const std::uint64_t fixint_mask = std::uint64_t{0} - is_fixint;
-        const std::uint64_t marker = 0xCBu + size_class + (sign_mask & 4u);
-        const auto first_byte = static_cast<std::uint8_t>((raw & fixint_mask) | (marker & ~fixint_mask));
-        return encode_first_byte_and_tail(out, first_byte, size_class, raw);
-    }
-
-    /// write a number_integer or number_unsigned value of a number type wider
-    /// than 64 bits as a MessagePack integer, with range checks on the whole value
-    void write_msgpack_integer(const BasicJsonType& j, std::false_type /*fits_64_bits*/)
-    {
-        if (j.m_data.m_type == value_t::number_unsigned)
-        {
-            if (JSON_HEDLEY_UNLIKELY(!integer_fits_max<std::uint64_t>(j.m_data.m_value.number_unsigned)))
-            {
-                throw_integer_out_of_range(j, "MessagePack", "uint64");
-            }
-            write_msgpack_unsigned(static_cast<std::uint64_t>(j.m_data.m_value.number_unsigned));
-            return;
-        }
-
-        if (j.m_data.m_value.number_integer >= 0)
-        {
-            if (JSON_HEDLEY_UNLIKELY(!integer_fits_max<std::uint64_t>(j.m_data.m_value.number_integer)))
-            {
-                throw_integer_out_of_range(j, "MessagePack", "[-2^63, 2^64-1]");
-            }
-            // MessagePack does not differentiate between positive
-            // signed integers and unsigned integers.
-            write_msgpack_unsigned(static_cast<std::uint64_t>(j.m_data.m_value.number_integer));
-        }
-        else
-        {
-            if (JSON_HEDLEY_UNLIKELY(!integer_fits_min<std::int64_t>(j.m_data.m_value.number_integer)))
-            {
-                throw_integer_out_of_range(j, "MessagePack", "[-2^63, 2^64-1]");
-            }
-            if (j.m_data.m_value.number_integer >= -32)
-            {
-                // negative fixnum
-                write_number(static_cast<std::int8_t>(j.m_data.m_value.number_integer));
-            }
-            else if (j.m_data.m_value.number_integer >= (std::numeric_limits<std::int8_t>::min)() &&
-                     j.m_data.m_value.number_integer <= (std::numeric_limits<std::int8_t>::max)())
-            {
-                // int 8
-                oa.write_character(to_char_type(0xD0));
-                write_number(static_cast<std::int8_t>(j.m_data.m_value.number_integer));
-            }
-            else if (j.m_data.m_value.number_integer >= (std::numeric_limits<std::int16_t>::min)() &&
-                     j.m_data.m_value.number_integer <= (std::numeric_limits<std::int16_t>::max)())
-            {
-                // int 16
-                oa.write_character(to_char_type(0xD1));
-                write_number(static_cast<std::int16_t>(j.m_data.m_value.number_integer));
-            }
-            else if (j.m_data.m_value.number_integer >= (std::numeric_limits<std::int32_t>::min)() &&
-                     j.m_data.m_value.number_integer <= (std::numeric_limits<std::int32_t>::max)())
-            {
-                // int 32
-                oa.write_character(to_char_type(0xD2));
-                write_number(static_cast<std::int32_t>(j.m_data.m_value.number_integer));
-            }
-            else
-            {
-                // int 64
-                oa.write_character(to_char_type(0xD3));
-                write_number(static_cast<std::int64_t>(j.m_data.m_value.number_integer));
-            }
-        }
-    }
-
-    /*!
-    @brief write an array value (head and elements) as MessagePack
-
-    See @ref write_cbor_array.
-    */
-    JSON_HEDLEY_NEVER_INLINE
-    void write_msgpack_array(const BasicJsonType& j, const std::size_t depth)
-    {
-        write_msgpack_array_prefix(j.m_data.m_value.array->size(), j);
-        write_msgpack_array_elements(j, depth, std::integral_constant<bool, integers_fit_64_bits()>());
-    }
-
-    void write_msgpack_array_elements(const BasicJsonType& j, const std::size_t depth, std::true_type /*fits_64_bits*/)
-    {
-        write_array_elements(j, [this](CharType * out, const BasicJsonType & el)
-        {
-            return encode_msgpack_integer(out, el);
-        }, [this, depth](const BasicJsonType & el)
-        {
-            write_msgpack(el, depth + 1);
-        });
-    }
-
-    void write_msgpack_array_elements(const BasicJsonType& j, const std::size_t depth, std::false_type /*fits_64_bits*/)
-    {
-        for (const auto& el : *j.m_data.m_value.array)
-        {
-            write_msgpack(el, depth + 1);
-        }
-    }
-
    /*!
    @brief write an object key as a CBOR text string

@@ -2599,7 +2147,7 @@ class binary_writer
        {
            return 'L';
        }
-        if (use_bjdata && std::is_unsigned<NumberType>::value && integer_fits_max<std::uint64_t>(n))
+        if (use_bjdata && std::is_unsigned<NumberType>::value)
        {
            return 'M';
        }
@@ -2724,16 +2272,14 @@ class binary_writer
    @brief checks whether a JSON number fits into @a TargetType
    @param[in] el a JSON number of either the signed or unsigned integer kind
    @return whether @a el's value can be represented by @a TargetType without
-            wrapping, regardless of which of the two kinds it is stored as;
-            false for a value that does not even fit the 64-bit type it is
-            read as (possible for number types wider than 64 bits)
+            wrapping, regardless of which of the two kinds it is stored as
    */
    template<typename TargetType>
    static bool bjdata_ndarray_value_in_range(const BasicJsonType& el)
    {
        return el.is_number_unsigned()
-               ? integer_fits_max<std::uint64_t>(el.m_data.m_value.number_unsigned) && value_in_range_of<TargetType>(el.template get<std::uint64_t>())
-               : integer_fits<std::int64_t>(el.m_data.m_value.number_integer) && value_in_range_of<TargetType>(el.template get<std::int64_t>());
+               ? value_in_range_of<TargetType>(el.template get<std::uint64_t>())
+               : value_in_range_of<TargetType>(el.template get<std::int64_t>());
    }

    /*!
@@ -2965,11 +2511,10 @@ class binary_writer
        for (const auto& el : dims)
        {
            // a dimension is read as an unsigned value below, so anything that
-            // is not a non-negative integer in the range of std::uint64_t is
-            // rejected: a non-integer entry would pun unrelated bytes as the
-            // dimension, and a negative or wider one would wrap into a
-            // nonsensical length
-            if (!el.is_number_integer() || !bjdata_ndarray_value_in_range<std::uint64_t>(el))
+            // is not a non-negative integer is rejected: a non-integer entry
+            // would pun unrelated bytes as the dimension, and a negative one
+            // would wrap into a nonsensical length
+            if (!el.is_number_integer() || (!el.is_number_unsigned() && el.template get<std::int64_t>() < 0))
            {
                return true;
            }
@@ -3101,9 +2646,9 @@ class binary_writer

            case value_t::number_unsigned:
            {
-                if (JSON_HEDLEY_UNLIKELY(!integer_fits_max<std::int64_t>(j.m_data.m_value.number_unsigned)))
+                if (j.m_data.m_value.number_unsigned > static_cast<typename BasicJsonType::number_unsigned_t>((std::numeric_limits<std::int64_t>::max)()))
                {
-                    throw_integer_out_of_range(j, "BON8", "int64");
+                    JSON_THROW(out_of_range::create(exception_id::integer_too_large, concat("integer number ", std::to_string(j.m_data.m_value.number_unsigned), " cannot be represented by BON8 as it does not fit int64"), &j));
                }
                write_bon8_integer(static_cast<std::int64_t>(j.m_data.m_value.number_unsigned));
                string_open = false;
@@ -3112,10 +2657,6 @@ class binary_writer

            case value_t::number_integer:
            {
-                if (JSON_HEDLEY_UNLIKELY(!integer_fits<std::int64_t>(j.m_data.m_value.number_integer)))
-                {
-                    throw_integer_out_of_range(j, "BON8", "int64");
-                }
                write_bon8_integer(static_cast<std::int64_t>(j.m_data.m_value.number_integer));
                string_open = false;
                break;
@@ -8,10 +8,7 @@

 #pragma once

-#include <algorithm> // max
-#include <array> // array
 #include <cstddef> // size_t
-#include <cstring> // memcpy
 #include <memory> // shared_ptr, make_shared
 #include <string> // basic_string
 #include <type_traits> // conditional, integral_constant, is_same
@@ -51,170 +48,32 @@ template<typename CharType> struct output_adapter_protocol
 template<typename CharType>
 using output_adapter_t = std::shared_ptr<output_adapter_protocol<CharType>>;

-/// the largest number of characters a writer may reserve() from a sink at once;
-/// output_vector_sink also appends writes of at least this size with insert()
-constexpr std::size_t max_reserve_size = 256;
-
 /// @brief non-virtual output sink writing into a std::vector
 ///
 /// This sink is not part of the virtual output_adapter_protocol hierarchy: it is
 /// passed to binary_writer by value as a template parameter, so
 /// write_character()/write_characters() are ordinary (inlinable) calls with no
 /// vtable lookup and no shared_ptr. It is used for the common
-/// `to_cbor`/`to_msgpack`/... into a std::vector.
-///
-/// Most writes are a few bytes - a type marker, or a number of 1, 2, 4, or 8
-/// bytes - and appending those with push_back() or insert() cost more than
-/// encoding them: insert() is an out-of-line call into a routine that can insert
-/// anywhere, and resize() is one as well with libstdc++. The sink therefore keeps
-/// its own write position: it grows the vector geometrically ahead of the
-/// position and copies each write to it, so a write is a capacity check and a
-/// short copy. The destructor shrinks the vector to the bytes actually written,
-/// also when a write throws; shrinking a vector never allocates. The sink owns
-/// that trim, so it can be moved but not copied, and the vector must not be used
-/// while the sink is alive.
+/// `to_cbor`/`to_msgpack`/... into a std::vector. output_vector_adapter below
+/// wraps this same sink to provide the virtual interface.
 template<typename CharType, typename AllocatorType = std::allocator<CharType>>
 class output_vector_sink
 {
  public:
    explicit output_vector_sink(std::vector<CharType, AllocatorType>& vec) noexcept
-        : v(&vec), position(vec.size())
-    {}
-
-    output_vector_sink(const output_vector_sink&) = delete;
-    output_vector_sink& operator=(const output_vector_sink&) = delete;
-    output_vector_sink& operator=(output_vector_sink&&) = delete;
-
-    output_vector_sink(output_vector_sink&& other) noexcept
-        : v(other.v), position(other.position)
-    {
-        other.v = nullptr;
-    }
-
-    ~output_vector_sink()
-    {
-        if (v != nullptr)
-        {
-            v->resize(position);
-        }
-    }
-
-    // always inlined: GCC otherwise keeps these out of line in a large
-    // translation unit, and a call per byte or number costs more than the write
-    JSON_HEDLEY_ALWAYS_INLINE
-    void write_character(CharType c)
-    {
-        if (JSON_HEDLEY_UNLIKELY(position == v->size()))
-        {
-            grow(1);
-        }
-        (*v)[position++] = c;
-    }
-
-    // no JSON_HEDLEY_NON_NULL here: binary_writer legitimately passes a null
-    // pointer with length 0 for empty strings/binary values; memcpy must not
-    // see it.
-    JSON_HEDLEY_ALWAYS_INLINE
-    void write_characters(const CharType* s, std::size_t length)
-    {
-        if (JSON_HEDLEY_UNLIKELY(v->size() - position < length))
-        {
-            if (length >= max_reserve_size)
-            {
-                append(s, length);
-                return;
-            }
-            grow(length);
-        }
-        if (length != 0)
-        {
-            std::memcpy(v->data() + position, s, length * sizeof(CharType));
-            position += length;
-        }
-    }
-
-    /// @brief space for writing up to @a length characters directly
-    ///
-    /// Returns a pointer to at least @a length (at most @ref max_reserve_size)
-    /// writable characters at the write position; @ref commit then keeps the
-    /// first ones of them. A writer can store whole words there and keep only
-    /// the bytes it needs, and keep its write pointer in a register across many
-    /// values instead of updating the sink after each.
-    JSON_HEDLEY_ALWAYS_INLINE
-    CharType* reserve(const std::size_t length)
-    {
-        JSON_ASSERT(length <= max_reserve_size);
-        if (JSON_HEDLEY_UNLIKELY(v->size() - position < length))
-        {
-            grow(length);
-        }
-        return v->data() + position;
-    }
-
-    /// keep the first @a length characters written to the space from reserve()
-    JSON_HEDLEY_ALWAYS_INLINE
-    void commit(const std::size_t length) noexcept
-    {
-        position += length;
-    }
-
-  private:
-    /// make room for at least @a length more characters after the position;
-    /// kept out of line so that the write functions stay small enough for
-    /// GCC to inline them into the writer
-    JSON_HEDLEY_NEVER_INLINE
-    void grow(const std::size_t length)
-    {
-        // use the capacity the vector already has, else at least double it;
-        // never less than 64 characters, so that a small value does not
-        // reallocate for every few bytes
-        const std::size_t needed = position + length;
-        v->resize((std::max)(std::size_t{64}, needed <= v->capacity()
-                             ? v->capacity()
-                             : (std::max)(needed, v->capacity() * 2)));
-    }
-
-    /// append @a length (at least max_reserve_size) characters that do not fit
-    /// the space ahead of the position: insert() copies them once into the
-    /// grown vector, where grow() would first zero the new space and then copy
-    /// over it - noticeable for a large string or binary value
-    JSON_HEDLEY_NEVER_INLINE
-    void append(const CharType* s, const std::size_t length)
-    {
-        v->resize(position);
-        if (v->capacity() - position < length)
-        {
-            // grow geometrically, with room for the writes that follow, so
-            // that the next grow() need not reallocate right away
-            v->reserve((std::max)(v->capacity() * 2, position + length + max_reserve_size));
-        }
-        v->insert(v->end(), s, s + length);
-        position = v->size();
-    }
-
-    std::vector<CharType, AllocatorType>* v;
-    /// number of characters of *v written so far
-    std::size_t position;
-};
-
-/// output adapter for byte vectors
-template<typename CharType, typename AllocatorType = std::allocator<CharType>>
-class output_vector_adapter : public output_adapter_protocol<CharType>
-{
-  public:
-    explicit output_vector_adapter(std::vector<CharType, AllocatorType>& vec) noexcept
        : v(vec)
    {}

-    void write_character(CharType c) override
+    void write_character(CharType c)
    {
        v.push_back(c);
    }

    // no JSON_HEDLEY_NON_NULL here: binary_writer legitimately passes a null
-    // pointer with length 0 for empty strings/binary values; appending an empty
-    // range is a no-op
-    void write_characters(const CharType* s, std::size_t length) override
+    // pointer with length 0 for empty strings/binary values. Appending an empty
+    // range is a no-op; the type-erased path tolerates this via the (unattributed)
+    // virtual base, and the concrete sink must do the same.
+    void write_characters(const CharType* s, std::size_t length)
    {
        v.insert(v.end(), s, s + length);
    }
@@ -223,6 +82,33 @@ class output_vector_adapter : public output_adapter_protocol<CharType>
    std::vector<CharType, AllocatorType>& v;
 };

+/// output adapter for byte vectors
+///
+/// The appending itself lives in output_vector_sink; this class only adds the
+/// virtual output_adapter_protocol interface on top of it, so both the
+/// type-erased and the templated path share one implementation.
+template<typename CharType, typename AllocatorType = std::allocator<CharType>>
+class output_vector_adapter : public output_adapter_protocol<CharType>
+{
+  public:
+    explicit output_vector_adapter(std::vector<CharType, AllocatorType>& vec) noexcept
+        : sink(vec)
+    {}
+
+    void write_character(CharType c) override
+    {
+        sink.write_character(c);
+    }
+
+    void write_characters(const CharType* s, std::size_t length) override
+    {
+        sink.write_characters(s, length);
+    }
+
+  private:
+    output_vector_sink<CharType, AllocatorType> sink;
+};
+
 #ifndef JSON_NO_IO
 /// output adapter for output streams
 template<typename CharType>
@@ -302,24 +188,8 @@ class output_adapter_sink
        oa->write_characters(s, length);
    }

-    /// space for writing up to @a length characters (see
-    /// output_vector_sink::reserve)
-    CharType* reserve(const std::size_t length) noexcept
-    {
-        JSON_ASSERT(length <= max_reserve_size);
-        static_cast<void>(length);
-        return reserved.data();
-    }
-
-    /// write the first @a length characters written to the space from reserve()
-    void commit(const std::size_t length)
-    {
-        oa->write_characters(reserved.data(), length);
-    }
-
  private:
    output_adapter_t<CharType> oa;
-    std::array<CharType, max_reserve_size> reserved{};
 };

 /// @brief whether std::basic_string<CharType> has a non-deprecated std::char_traits
@@ -1525,7 +1525,7 @@ class serializer
        // without leading zeros
        if (abs_value < 10000000000000000u)
        {
-            const auto value = static_cast<std::uint64_t>(abs_value); // fits: abs_value < 10^16
+            const std::uint64_t value = abs_value;
            const std::uint64_t upper = value / 100000000u;
            const std::uint64_t first = dtoa_impl::eight_digit_bytes(upper != 0 ? upper : value);
            const auto leading = static_cast<unsigned>(count_leading_zeros(first) / 8); // (first is not 0)
@@ -14,6 +14,7 @@
 #include <cstdint> // uint8_t
 #include <limits> // numeric_limits
 #include <string> // string
+#include <type_traits> // is_signed

 #include <nlohmann/detail/macro_scope.hpp>
 #if JSON_HAS_THREE_WAY_COMPARISON
@@ -207,16 +208,13 @@ FloatType compare_integer_with_float(const IntegerType i, const FloatType f) noe

    // values of IntegerType lie in [-bound, bound) when signed and in
    // [0, bound) when unsigned; digits excludes the sign bit, so bound is a
-    // power of two that the float represents exactly; the signedness comes
-    // from numeric_limits as well, because std::is_signed is false for class
-    // types such as 128-bit or multiprecision integers
-    using limits = std::numeric_limits<IntegerType>;
-    const FloatType bound = std::ldexp(static_cast<FloatType>(1), limits::digits);
+    // power of two that the float represents exactly
+    const FloatType bound = std::ldexp(static_cast<FloatType>(1), std::numeric_limits<IntegerType>::digits);
    if (f >= bound)
    {
        return ordered(-1);
    }
-    if (limits::is_signed ? (f < -bound) : (f < static_cast<FloatType>(0)))
+    if (std::is_signed<IntegerType>::value ? (f < -bound) : (f < static_cast<FloatType>(0)))
    {
        return ordered(1);
    }
@@ -11,7 +11,7 @@
 #include <array> // array
 #include <cstddef> // size_t
 #include <cstdint> // uint8_t, uint32_t
-#include <cstring> // memcmp, memcpy
+#include <cstring> // memcpy
 #include <limits> // numeric_limits
 #include <map> // map
 #include <memory> // unique_ptr
@@ -56,16 +56,14 @@ struct document_data
    std::vector<object_index> indexes;
    std::vector<std::uint32_t> index_slots;
    std::vector<std::uint32_t> large_objects; ///< positions of the objects to index (noted while parsing)
-    std::array<const char*, 4> base = {{nullptr, nullptr, nullptr, nullptr}}; ///< string bases: source, arena, edit arena, unused (indexed by flags & node_flags::storage)
+    std::array<const char*, 4> base = {{nullptr, nullptr, nullptr, nullptr}}; ///< string bases: source, arena, edit arena (indexed by flags & node_flags::storage)
    bool discarded = true;

    /// The storage of edits (editable documents only; see edit_storage.hpp).
-    /// No edit moves or resizes the parsed index, and the nodes of values
-    /// written by edits never move either, so a view stays valid whenever it
-    /// was taken, before the first edit or between later ones: an array/object
-    /// whose elements change gets node_flags::moved, and its elements then live
-    /// in a separate sequence (a header node, then the entries), whose entries
-    /// link to the values.
+    /// Edits never move or resize the parsed index, so views stay valid: an
+    /// array/object whose elements change gets node_flags::moved, and its
+    /// elements then live in a separate sequence (a header node, then the
+    /// entries), whose entries link to the values.
    struct edit_state
    {
        std::vector<node*> moved{};                    ///< element sequences of moved arrays/objects (header node first) // NOLINT(readability-redundant-member-init)
@@ -185,12 +183,6 @@ struct document_data
        return base[n.flags & node_flags::storage] + n.off;
    }

-    /// whether the string of node k (a key) is the n bytes at key
-    bool key_equals(const node& k, const char* key, std::size_t n) const noexcept
-    {
-        return k.len == n && (n == 0 || std::memcmp(str(k), key, n) == 0);
-    }
-
    /// the node after n's subtree (containers span `next` nodes, scalars one)
    static NLOHMANN_VIEW_ALWAYS_INLINE const node* after(const node* n) noexcept
    {
@@ -12,7 +12,7 @@
 #include <cmath> // isinf, isnan
 #include <cstddef> // size_t
 #include <cstdint> // int64_t, uint8_t, uint32_t, uint64_t
-#include <cstring> // memmove
+#include <cstring> // memcmp, memmove
 #include <limits> // numeric_limits
 #include <string> // string, to_string
 #include <type_traits> // decay, enable_if, integral_constant, is_arithmetic, is_convertible, is_floating_point, is_same, is_signed
@@ -313,7 +313,7 @@ class editor

    bool key_equals(const node& k, string_view_t key) const noexcept
    {
-        return m_doc.key_equals(k, key.data(), key.size());
+        return k.len == key.size() && (key.size() == 0 || std::memcmp(m_doc.str(k), key.data(), key.size()) == 0);
    }

    /// remove the members with this key (all, or all but the first) from an object
@@ -50,19 +50,7 @@ inline node* alloc_nodes(document_data& d, std::size_t k)
    document_data::edit_state& e = edit_state_of(d);
    if (NLOHMANN_VIEW_UNLIKELY(static_cast<std::size_t>(e.chunk_end - e.chunk_cur) < k))
    {
-        if (k >= e.chunk_next / 2)
-        {
-            // a large request (half of the next chunk or more) gets a chunk of
-            // its own, so that the rest of the current chunk stays available
-            // for smaller ones
-            std::unique_ptr<node[]> own(new node[k]()); // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
-            e.chunks.push_back(std::move(own));
-            e.bytes += k * sizeof(node);
-            return e.chunks.back().get();
-        }
-        // a smaller request leaves the rest of the current chunk unused
-        // (fewer than k nodes, and k is less than half of the new chunk)
-        const std::size_t count = e.chunk_next;
+        const std::size_t count = (std::max)(k, e.chunk_next);
        std::unique_ptr<node[]> fresh(new node[count]()); // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
        e.chunks.push_back(std::move(fresh));
        e.chunk_cur = e.chunks.back().get();
@@ -93,8 +81,7 @@ inline std::size_t text_capacity(std::size_t cap, std::size_t used, std::size_t
 }

 /// copy n bytes into the edit arena and return their offset; a new buffer
-/// leaves the old one alive, so that string views into it remain valid; n is
-/// 0 for an empty string (written by an edit, or the key of a new member)
+/// leaves the old one alive, so that string views into it remain valid
 inline std::uint32_t append_text(document_data& d, const char* s, std::size_t n)
 {
    document_data::edit_state& e = edit_state_of(d);
@@ -102,7 +89,7 @@ inline std::uint32_t append_text(document_data& d, const char* s, std::size_t n)
    {
        const std::size_t cap = text_capacity(e.text_cap, e.text_used, n);
        std::unique_ptr<char[]> fresh(new char[cap]); // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
-        if (NLOHMANN_VIEW_LIKELY(e.text_used != 0)) // (0 only for the first buffer, and then texts is empty)
+        if (e.text_used != 0)
        {
            std::memcpy(fresh.get(), e.texts.back().get(), e.text_used);
        }
@@ -140,10 +127,8 @@ inline void reserve_moved(document_data& d)
    if (e.moved.size() == e.moved.capacity() || e.moved_cap.size() == e.moved_cap.capacity())
    {
        // both grow before either changes, so that the push_backs cannot throw
-        // (both conditions are needed: reserve() may allocate more than asked,
-        // so the two capacities can differ)
-        e.moved.reserve((e.moved.size() * 2) + 16);
-        e.moved_cap.reserve((e.moved.size() * 2) + 16);
+        e.moved.reserve((2 * e.moved.size()) + 16);
+        e.moved_cap.reserve((2 * e.moved.size()) + 16);
    }
 }

@@ -8,11 +8,11 @@

 #pragma once

-#include <algorithm> // min, sort
+#include <algorithm> // sort
 #include <array> // array
-#include <cstddef> // offsetof, size_t
+#include <cstddef> // size_t
 #include <cstdint> // int64_t, uint8_t, uint16_t, uint32_t, uint64_t
-#include <cstring> // memcmp, memcpy, memset
+#include <cstring> // memcmp, memcpy
 #include <limits> // numeric_limits
 #include <string> // string
 #include <vector> // vector
@@ -162,7 +162,7 @@ inline void compact_nodes(const document_data& d, std::size_t arena_size, std::v
    copy_node(d.nodes);
    while (!stack.empty())
    {
-        const frame top = stack.back();
+        frame& top = stack.back();
        if (top.cur == top.end)
        {
            node& c = out[top.index];
@@ -171,14 +171,20 @@ inline void compact_nodes(const document_data& d, std::size_t arena_size, std::v
            stack.pop_back();
            continue;
        }
+        ++top.count;
+        const node* v = nullptr;
        if (top.object)
        {
            out.push_back(string_node(*top.cur));
+            v = document_data::deref(top.cur + 1);
+            top.cur = document_data::after(top.cur + 1);
        }
-        const node* const value = top.cur + (top.object ? 1 : 0);
-        stack.back().cur = document_data::after(value);
-        ++stack.back().count;
-        copy_node(document_data::deref(value)); // may grow the stack
+        else
+        {
+            v = document_data::deref(top.cur);
+            top.cur = document_data::after(top.cur);
+        }
+        copy_node(v); // may grow the stack (top is not used afterwards)
    }
 }

@@ -189,15 +195,17 @@ inline std::vector<std::uint8_t> save_image(const document_data& d)
    throw_type_error(320, "json_document images need a little-endian target"); // LCOV_EXCL_LINE
 #endif
    const std::size_t arena_size = d.arena_size;
+    const node* nodes = d.nodes;
+    std::size_t count = d.node_count;
    std::vector<node> compacted;
    std::string text_tail;
    std::string arena_tail;
    if (d.edits)
    {
        compact_nodes(d, arena_size, compacted, text_tail, arena_tail);
+        nodes = compacted.data();
+        count = compacted.size();
    }
-    const node* const nodes = d.edits ? compacted.data() : d.nodes;
-    const std::size_t count = d.edits ? compacted.size() : d.node_count;
    const std::size_t text_size = d.size + text_tail.size();
    const std::size_t total_arena = arena_size + arena_tail.size();
    if (NLOHMANN_VIEW_UNLIKELY(text_size >= image_limit || total_arena >= image_limit || count >= image_limit))
@@ -217,13 +225,14 @@ inline std::vector<std::uint8_t> save_image(const document_data& d)
    std::memcpy(o, &h, sizeof(h));
    o += sizeof(h);
    std::memcpy(o, nodes, count * sizeof(node));
-    // the hash indexes are rebuilt by load(), whose check rejects any other
-    // extra of an object, and the same document saves to the same bytes
+    // the hash indexes are rebuilt by load()
    for (std::size_t i = 0; i < count; ++i)
    {
        if (nodes[i].kind == static_cast<std::uint8_t>(value_t::object) && nodes[i].extra != 0)
        {
-            std::memset(o + (i * sizeof(node)) + offsetof(node, extra), 0, sizeof(nodes[i].extra));
+            node n = nodes[i];
+            n.extra = 0;
+            std::memcpy(o + (i * sizeof(node)), &n, sizeof(node));
        }
    }
    o += count * sizeof(node);
@@ -262,22 +271,21 @@ inline bool scan_number_token(const unsigned char* s, std::size_t len, number_to
    const unsigned char* p = s;
    t.negative = p != e && *p == '-';
    p += t.negative ? 1 : 0;
+    t.int_start = p;
    if (p == e)
    {
        return false;
    }
-    t.int_start = p;
    if (*p == '0')
    {
        ++p;
    }
    else if (*p >= '1' && *p <= '9')
    {
-        do
+        while (p != e && is_digit(*p))
        {
            ++p;
        }
-        while (p != e && is_digit(*p));
    }
    else
    {
@@ -310,12 +318,11 @@ inline bool scan_number_token(const unsigned char* s, std::size_t len, number_to
        {
            return false;
        }
-        do
+        while (p != e && is_digit(*p))
        {
            t.exponent = t.exponent < 100000 ? (t.exponent * 10) + (*p - '0') : t.exponent;
            ++p;
        }
-        while (p != e && is_digit(*p));
        t.exponent = exp_negative ? -t.exponent : t.exponent;
        t.is_float = true;
    }
@@ -326,7 +333,7 @@ inline bool scan_number_token(const unsigned char* s, std::size_t len, number_to
 /// writes "many" instead; the caller accepts both)
 inline std::uint16_t float_layout(const number_token& t)
 {
-    return static_cast<std::uint16_t>((std::min)(t.int_digits, std::size_t{255}) | ((std::min)(t.frac_digits, std::size_t{255}) << 8u));
+    return static_cast<std::uint16_t>((t.int_digits < 255 ? t.int_digits : 255) | ((t.frac_digits < 255 ? t.frac_digits : 255) << 8u));
 }

 /// whether a float token (well-formed, per scan_number_token) is finite as
@@ -728,10 +735,14 @@ inline void load_image(document_data& d, const std::uint8_t* image, std::size_t
    // the hash indexes of large objects, as after parsing
    for (std::size_t i = 0; i < count; ++i)
    {
-        const node& n = d.nodes[i];
-        if (n.kind == static_cast<std::uint8_t>(value_t::object) && n.len >= document_data::index_min_members)
+        node& n = d.nodes[i];
+        if (n.kind == static_cast<std::uint8_t>(value_t::object))
        {
-            d.large_objects.push_back(static_cast<std::uint32_t>(i));
+            n.extra = 0;
+            if (n.len >= document_data::index_min_members)
+            {
+                d.large_objects.push_back(static_cast<std::uint32_t>(i));
+            }
        }
    }
    build_object_indexes(d);
@@ -112,7 +112,7 @@ const node* find_member(const document_data& d, const node* object, const char*
    }
    for (const node* m = nav::first(d, object); m != end; m = document_data::after(m + 1))
    {
-        if (d.key_equals(*m, key, n))
+        if (m->len == n && std::memcmp(d.str(*m), key, n) == 0)
        {
            return m;
        }
@@ -129,7 +129,7 @@ std::size_t count_members(const document_data& d, const node* object, const char
    const node* const end = nav::end(d, object);
    for (const node* m = nav::first(d, object); m != end; m = document_data::after(m + 1))
    {
-        if (d.key_equals(*m, key, n))
+        if (m->len == n && (n == 0 || std::memcmp(d.str(*m), key, n) == 0))
        {
            ++result;
        }
@@ -34,7 +34,7 @@ struct node_flags
 {
    static constexpr std::uint8_t escaped = 1; ///< string payload lives in the decode arena, not the source
    static constexpr std::uint8_t edited = 2;  ///< string or number token lives in the edit arena (editable documents)
-    static constexpr std::uint8_t storage = escaped | edited; ///< mask: where a string or number token lives (index into document_data::base)
+    static constexpr std::uint8_t storage = 3; ///< mask: where a string or number token lives (index into document_data::base)
    static constexpr std::uint8_t is_true = 4; ///< boolean value
    static constexpr std::uint8_t moved = 8;   ///< array/object: the elements live in a separate sequence (editable documents)
    static constexpr std::uint8_t is_new = 16; ///< written by an edit: no source position
@@ -45,11 +45,10 @@ inline bool float_token_layout(const char* first, const char* last, std::size_t&
    {
        return false;
    }
-    do
+    while (digit(p))
    {
        ++p;
    }
-    while (digit(p));
    dot = std::string::npos;
    if (p != last && *p == '.')
    {
@@ -58,11 +57,10 @@ inline bool float_token_layout(const char* first, const char* last, std::size_t&
        {
            return false;
        }
-        do
+        while (digit(p))
        {
            ++p;
        }
-        while (digit(p));
    }
    mantissa_end = static_cast<std::size_t>(p - first);
    if (p != last && (*p == 'e' || *p == 'E'))
@@ -73,11 +71,10 @@ inline bool float_token_layout(const char* first, const char* last, std::size_t&
        {
            return false;
        }
-        do
+        while (digit(p))
        {
            ++p;
        }
-        while (digit(p));
    }
    return p == last;
 }
@@ -10,8 +10,10 @@

 #include <cstddef> // size_t
 #include <cstdint> // uint32_t, uint64_t
+#include <cstring> // memcmp

 #include <nlohmann/json.hpp>
+#include <nlohmann/detail/meta/type_traits.hpp>
 #include <nlohmann/detail/view/document_data.hpp>
 #include <nlohmann/detail/view/macro_scope.hpp>
 #include <nlohmann/detail/view/node.hpp>
@@ -93,7 +95,7 @@ inline void build_object_index(document_data& d, node* obj)
        while (table[slot] != 0)
        {
            const node* const other = obj + table[slot];
-            if (d.key_equals(*other, key, k->len))
+            if (other->len == k->len && (k->len == 0 || std::memcmp(d.str(*other), key, k->len) == 0))
            {
                duplicate = true; // keep the first
                break;
@@ -140,7 +142,7 @@ inline const node* find_indexed(const document_data& d, const node* obj, const c
            return nullptr;
        }
        const node* const k = obj + s;
-        if (d.key_equals(*k, key, n))
+        if (k->len == n && (n == 0 || std::memcmp(d.str(*k), key, n) == 0))
        {
            return k;
        }
@@ -175,7 +175,32 @@ NLOHMANN_VIEW_ALWAYS_INLINE const unsigned char* skip_digits(const unsigned char
 /// powers of ten up to 10^19 as integers
 inline std::uint64_t int_pow10(unsigned k) noexcept
 {
-    return ::nlohmann::detail::dtoa_impl::powers_of_ten()[k];
+    static const std::array<std::uint64_t, 20> table =
+    {
+        {
+            1u,
+            10u,
+            100u,
+            1000u,
+            10000u,
+            100000u,
+            1000000u,
+            10000000u,
+            100000000u,
+            1000000000u,
+            10000000000u,
+            100000000000u,
+            1000000000000u,
+            10000000000000u,
+            100000000000000u,
+            1000000000000000u,
+            10000000000000000u,
+            100000000000000000u,
+            1000000000000000000u,
+            10000000000000000000u
+        }
+    };
+    return table[k];
 }

 /// value of 0 < k < 8 digits at p in one step if [p, p + 8) lies below
@@ -75,7 +75,7 @@ class output_buffer

    /// a string literal, without its terminating NUL
    template<std::size_t N>
-    NLOHMANN_VIEW_ALWAYS_INLINE void put(const char (&s)[N]) // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
+    NLOHMANN_VIEW_ALWAYS_INLINE void put(const char (&s)[N])
    {
        put(s, N - 1);
    }
@@ -109,7 +109,7 @@ class output_buffer
    /// which a static constexpr member does not have before C++17)
    static constexpr std::size_t step() noexcept
    {
-        return 0x10000;
+        return 65536;
    }

    static StringType& sized(StringType& out, std::size_t estimate)
@@ -174,17 +174,14 @@ inline std::size_t plain_output_run(const unsigned char* s, std::size_t n) noexc
 /// A stack that starts in a buffer of the caller (a local array) and moves to
 /// the heap (a vector of the caller) only when that is full, so that dumps of
 /// shallow documents need no allocation. The top is a pointer, as in
-/// std::vector. grow() is static and out of line: it gets the vector and the
-/// used range and returns the new storage, so the address of the stack never
-/// reaches a call. Otherwise the compiler would have to keep the three
-/// pointers in memory and load and store them on every push_back() and
-/// pop_back(), not just when growing.
+/// std::vector. The address of the stack never escapes (the growth gets the
+/// vector and returns the new storage), so its pointers stay in registers.
 template<typename T>
 class small_stack
 {
  public:
    small_stack(T* buffer, std::size_t capacity, std::vector<T>& heap) noexcept
-        : m_begin(buffer), m_top(buffer), m_end(buffer + capacity), m_heap(heap)
+        : m_begin(buffer), m_top(buffer), m_end(buffer + capacity), m_heap(&heap)
    {}
    small_stack(const small_stack&) = delete;
    small_stack(small_stack&&) = delete;
@@ -198,7 +195,7 @@ class small_stack
        {
            const std::size_t used = size();
            const std::size_t capacity = 2 * static_cast<std::size_t>(m_end - m_begin);
-            m_begin = grow(m_heap, m_begin, used, capacity);
+            m_begin = grow(*m_heap, m_begin, used, capacity);
            m_top = m_begin + used;
            m_end = m_begin + capacity;
        }
@@ -238,18 +235,9 @@ class small_stack
    T* m_begin;
    T* m_top;
    T* m_end;
-    std::vector<T>& m_heap;
+    std::vector<T>* m_heap;
 };

-/// a string literal at w, without its terminating NUL (after room())
-/// @return a pointer past it
-template<std::size_t N>
-NLOHMANN_VIEW_ALWAYS_INLINE char* put_literal(char* w, const char (&s)[N]) noexcept // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
-{
-    std::memcpy(w, s, N - 1);
-    return w + N - 1;
-}
-
 /// how the view's dump() writes a value
 struct dump_style
 {
@@ -338,15 +326,15 @@ class view_serializer
                    m_out.finish();
                    return;
                }
-                if (stack.back().pos == stack.back().end)
+                frame& f = stack.back();
+                if (f.pos == f.end)
                {
-                    const bool object = stack.back().object;
+                    const bool object = f.object; // (f dangles after pop_back)
                    stack.pop_back();
                    newline(stack.size());
                    m_out.put(object ? '}' : ']');
                    continue;
                }
-                frame& f = stack.back();
                if (!f.first)
                {
                    m_out.put(',');
@@ -473,6 +461,12 @@ class view_serializer
            }
            w += n;
        };
+        // a literal of n bytes (after room(n))
+        const auto literal = [&](const char* text, std::size_t n)
+        {
+            std::memcpy(w, text, n);
+            w += n;
+        };
        // a string that is not a plain string of the source (out of line, so
        // that the cursor stays in a register here)
        const auto escaped = [&](const node & n)
@@ -558,11 +552,11 @@ class view_serializer
                    room(8);
                    if ((n->flags & node_flags::is_true) != 0)
                    {
-                        w = put_literal(w, "true");
+                        literal("true", 4);
                    }
                    else
                    {
-                        w = put_literal(w, "false");
+                        literal("false", 5);
                    }
                    break;
                case value_t::object:
@@ -572,7 +566,7 @@ class view_serializer
                    room(8);
                    if (n->len == 0)
                    {
-                        w = object ? put_literal(w, "{}") : put_literal(w, "[]");
+                        literal(object ? "{}" : "[]", 2);
                    }
                    else
                    {
@@ -592,7 +586,7 @@ class view_serializer
                }
                case value_t::null:
                    room(8);
-                    w = put_literal(w, "null");
+                    literal("null", 4);
                    break;
                case value_t::binary:    // LCOV_EXCL_LINE (not in a document)
                case value_t::discarded: // LCOV_EXCL_LINE
@@ -772,7 +766,7 @@ class view_serializer
                // check also keeps an image that was only checked for bounds,
                // whose token may not be made of digits, from the counted
                // overload)
-                const auto& powers = ::nlohmann::detail::dtoa_impl::powers_of_ten();
+                const auto& powers = ::nlohmann::detail::dtoa_impl::powers_of_ten_16();
                const unsigned count = int_digits + frac_digits;
                return count - 1u < 15u && d.w >= powers[count - 1u] && d.w < powers[count]
                       ? ::nlohmann::detail::dtoa_impl::write_short_decimal(w, d.w, static_cast<int>(count), static_cast<int>(d.exponent))
@@ -12,7 +12,7 @@
 #include <cstdint> // int64_t
 #include <map> // map
 #include <string> // basic_string
-#include <type_traits> // decay, enable_if, is_arithmetic, is_constructible, is_integral, is_same
+#include <type_traits> // enable_if, is_constructible
 #include <unordered_map> // unordered_map
 #include <vector> // vector

@@ -104,20 +104,6 @@ Map map_value(const View& v)
 template<typename Key>
 struct is_string_key : std::is_constructible<Key, const char*, std::size_t> {};

-/// the arithmetic types arithmetic_value() converts to (bool has its own
-/// conversion)
-template<typename T>
-struct is_non_bool_arithmetic : conjunction<std::is_arithmetic<T>, negation<std::is_same<T, bool>>> {};
-
-/// the default values of value() other than C strings, which have their own
-/// overload (returning string_t)
-template<typename T>
-struct is_non_c_string_default : negation<std::is_same<typename std::decay<T>::type, const char*>> {};
-
-/// the integral types accepted as an array index by the edits of a document
-template<typename T>
-struct is_non_bool_integral : conjunction<std::is_integral<T>, negation<std::is_same<T, bool>>> {};
-
 /// whether View::get<T>() converts to T without materialize(); get_to()
 /// assigns these, and passes the others to from_json
 template<typename T, typename BasicJsonType, typename View>
@@ -379,7 +379,7 @@ class basic_json_view
    /// the member with this key converted to T, or the default value if there
    /// is no such member (the first one, should the key occur more than
    /// once). Throws type_error.306 if this is not an object.
-    template<typename T, typename std::enable_if<detail::view::is_non_c_string_default<T>::value, int>::type = 0>
+    template < typename T, typename std::enable_if < !std::is_same<typename std::decay<T>::type, const char*>::value, int >::type = 0 >
    T value(string_view_t key, const T& default_value) const
    {
        if (NLOHMANN_VIEW_UNLIKELY(!is_object()))
@@ -398,7 +398,7 @@ class basic_json_view
    /// the value a JSON pointer refers to converted to T, or the default
    /// value if the pointer cannot be resolved. Throws type_error.306 if this
    /// is neither an object nor an array.
-    template<typename T, typename std::enable_if<detail::view::is_non_c_string_default<T>::value, int>::type = 0>
+    template < typename T, typename std::enable_if < !std::is_same<typename std::decay<T>::type, const char*>::value, int >::type = 0 >
    T value(const json_pointer& ptr, const T& default_value) const
    {
        if (NLOHMANN_VIEW_UNLIKELY(!is_structured()))
@@ -750,10 +750,8 @@ class basic_json_view
    {
        if (editable() && m_doc->edits != nullptr)
        {
-            // positions of moved and new values are not source offsets; the root
-            // (the first node) spans the source text and every edit
-            const bool is_root = m_node == m_doc->nodes;
-            return is_root ? m_doc->size + m_doc->edits->text_used : 64;
+            // positions of moved and new values are not source offsets
+            return m_node == m_doc->nodes ? m_doc->size + m_doc->edits->text_used : 64;
        }
        const node* const end = m_doc->nodes + m_doc->node_count;
        if ((m_node->flags & detail::view::node_flags::storage) != 0)
@@ -800,7 +798,7 @@ class basic_json_view
        return (m_node->flags & detail::view::node_flags::is_true) != 0;
    }

-    template<typename T, typename std::enable_if<detail::view::is_non_bool_arithmetic<T>::value, int>::type = 0>
+    template < typename T, typename std::enable_if < std::is_arithmetic<T>::value && !std::is_same<T, bool>::value, int >::type = 0 >
    NLOHMANN_VIEW_ALWAYS_INLINE T get_impl(detail::view::value_tag<T> /*unused*/, detail::priority_tag<2> /*unused*/) const
    {
        if (NLOHMANN_VIEW_UNLIKELY(m_node == nullptr))
@@ -1040,7 +1038,7 @@ class basic_json_document
        return m_data ? m_data->node_count : 0;
    }

-    /// bytes held by the document (index, decoded strings, and owned text or image)
+    /// bytes held by the document (index, decoded strings, owned text or image)
    std::size_t memory_usage() const noexcept
    {
        if (!m_data)
@@ -1188,7 +1186,7 @@ class basic_json_document
    }

    /// assign an existing array element; returns a view of it
-    template<typename I, typename V, typename std::enable_if<detail::view::is_non_bool_integral<I>::value, int>::type = 0>
+    template < typename I, typename V, typename std::enable_if < std::is_integral<I>::value && !std::is_same<I, bool>::value, int >::type = 0 >
    view_type set(view_type array, I idx, V && value)
    {
        return editor().set(array, index(idx), std::forward<V>(value));
@@ -1210,14 +1208,14 @@ class basic_json_document
        const auto& token = ptr.back();
        if (parent.is_null())
        {
-            if (token == "-")
-            {
-                return push_back(parent, std::forward<V>(value));
-            }
            const bool digits = std::all_of(token.begin(), token.end(), [](const char c)
            {
                return c >= '0' && c <= '9';
            });
+            if (token == "-")
+            {
+                return push_back(parent, std::forward<V>(value));
+            }
            if (digits)
            {
                // (an invalid index is an error before the parent changes)
@@ -1255,7 +1253,7 @@ class basic_json_document

    /// insert into an array before position idx (idx <= size()); returns a
    /// view of the new element
-    template<typename I, typename V, typename std::enable_if<detail::view::is_non_bool_integral<I>::value, int>::type = 0>
+    template < typename I, typename V, typename std::enable_if < std::is_integral<I>::value && !std::is_same<I, bool>::value, int >::type = 0 >
    view_type insert(view_type array, I idx, V && value)
    {
        return editor().insert(array, index(idx), std::forward<V>(value));
@@ -1268,7 +1266,7 @@ class basic_json_document
    }

    /// remove an array element
-    template<typename I, typename std::enable_if<detail::view::is_non_bool_integral<I>::value, int>::type = 0>
+    template < typename I, typename std::enable_if < std::is_integral<I>::value && !std::is_same<I, bool>::value, int >::type = 0 >
    void erase(view_type array, I idx)
    {
        editor().erase(array, index(idx));
@@ -71,14 +71,6 @@
    #define JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS 0
 #endif

-#ifndef JSON_DISABLE_STREAM_BULK_SCAN
-    #define JSON_DISABLE_STREAM_BULK_SCAN 0
-#endif
-
-#ifndef JSON_DISABLE_UNLOCKED_FILE_IO
-    #define JSON_DISABLE_UNLOCKED_FILE_IO 0
-#endif
-
 #if JSON_DIAGNOSTICS
    #define NLOHMANN_JSON_ABI_TAG_DIAGNOSTICS _diag
 #else
@@ -127,18 +119,6 @@
    #define NLOHMANN_JSON_ABI_TAG_OBJECTS_FOR_ENUM_KEYED_MAPS
 #endif

-#if JSON_DISABLE_STREAM_BULK_SCAN
-    #define NLOHMANN_JSON_ABI_TAG_DISABLE_STREAM_BULK_SCAN _dsbs
-#else
-    #define NLOHMANN_JSON_ABI_TAG_DISABLE_STREAM_BULK_SCAN
-#endif
-
-#if JSON_DISABLE_UNLOCKED_FILE_IO
-    #define NLOHMANN_JSON_ABI_TAG_DISABLE_UNLOCKED_FILE_IO _dufio
-#else
-    #define NLOHMANN_JSON_ABI_TAG_DISABLE_UNLOCKED_FILE_IO
-#endif
-
 #ifdef JSON_VIEW_NO_SIMD
    #define NLOHMANN_JSON_ABI_TAG_VIEW_NO_SIMD _vns
 #else
@@ -156,9 +136,9 @@
 #endif

 // Construct the namespace ABI tags component
-#define NLOHMANN_JSON_ABI_TAGS_CONCAT_EX(a, b, c, d, e, f, g, h, i, j, k, l) json_abi ## a ## b ## c ## d ## e ## f ## g ## h ## i ## j ## k ## l
-#define NLOHMANN_JSON_ABI_TAGS_CONCAT(a, b, c, d, e, f, g, h, i, j, k, l) \
-    NLOHMANN_JSON_ABI_TAGS_CONCAT_EX(a, b, c, d, e, f, g, h, i, j, k, l)
+#define NLOHMANN_JSON_ABI_TAGS_CONCAT_EX(a, b, c, d, e, f, g, h, i, j) json_abi ## a ## b ## c ## d ## e ## f ## g ## h ## i ## j
+#define NLOHMANN_JSON_ABI_TAGS_CONCAT(a, b, c, d, e, f, g, h, i, j) \
+    NLOHMANN_JSON_ABI_TAGS_CONCAT_EX(a, b, c, d, e, f, g, h, i, j)

 #define NLOHMANN_JSON_ABI_TAGS                                       \
    NLOHMANN_JSON_ABI_TAGS_CONCAT(                                   \
@@ -170,8 +150,6 @@
            NLOHMANN_JSON_ABI_TAG_STRICT_NUL_HANDLING,               \
            NLOHMANN_JSON_ABI_TAG_STRICT_BINARY_UTF8,                \
            NLOHMANN_JSON_ABI_TAG_OBJECTS_FOR_ENUM_KEYED_MAPS,       \
-            NLOHMANN_JSON_ABI_TAG_DISABLE_STREAM_BULK_SCAN,          \
-            NLOHMANN_JSON_ABI_TAG_DISABLE_UNLOCKED_FILE_IO,          \
            NLOHMANN_JSON_ABI_TAG_VIEW_NO_SIMD,                      \
            NLOHMANN_JSON_ABI_TAG_VIEW_USE_SSSE3)

@@ -2,14 +2,12 @@ cmake_minimum_required(VERSION 3.13...4.0)

 option(JSON_Valgrind    "Execute test suite with Valgrind." OFF)
 option(JSON_FastTests   "Skip expensive/slow tests." OFF)
-option(JSON_TestUnityBuild "Build the unit tests in batches of several files per executable to speed up compilation." ON)
 option(JSON_TestSimdutf "Build the unit tests against the simdutf UTF-8 validation backend." OFF)

 set(JSON_SIMDUTF_VERSION 9.1.0 CACHE STRING "The simdutf version used by JSON_TestSimdutf.")

 set(JSON_32bitTest     AUTO CACHE STRING "Enable the 32bit unit test (ON/OFF/AUTO/ONLY).")
 set(JSON_TestStandards "" CACHE STRING "The list of standards to test explicitly.")
-set(JSON_TestUnityBatchSize 8 CACHE STRING "The number of unit test files compiled into one executable with JSON_TestUnityBuild.")
 set(JSON_TestShard     "" CACHE STRING "Build only a part of the unit tests, given as <index>/<count> (e.g. 0/2), to split them across CI jobs with a time limit.")

 # using an env var, since this will also affect targets executing cmake (such as "ci_test_compiler_default")
@@ -22,11 +20,6 @@ endif()

 include(test)

-# MinGW's GNU ld hits section and relocation limits with the large merged translation units
-if(MINGW)
-    set(JSON_TestUnityBuild OFF)
-endif()
-
 #############################################################################
 # override standard support
 #############################################################################
@@ -292,10 +285,6 @@ if (JSON_TestSimdutf)
    endif()
 endif()

-# test-file_input checks from a second thread that parsing from a FILE* releases the file's lock
-find_package(Threads REQUIRED)
-json_test_set_test_options("test-file_input;test-file_input_unlocked_io_disabled" LINK_LIBRARIES Threads::Threads)
-
 # *DO* use json_test_set_test_options() above this line

 json_test_should_build_32bit_test(json_32bit_test json_32bit_test_only "${JSON_32bitTest}")
@@ -333,28 +322,9 @@ if(NOT "${JSON_TestShard}" STREQUAL "")
    message(STATUS "Test shard ${JSON_TestShard}: ${shard_file_count} of ${test_file_count} unit test files")
 endif()

-# Explicit groups of test files (file names without "unit-" and ".cpp") for
-# JSON_TestUnityBuild: all files of a group are compiled into one translation
-# unit per C++ standard, so that related tests share their template
-# instantiations (all binary formats instantiate the same readers and
-# writers). Only add a group where this was measured to pay off: grouping
-# files that share little just creates one slow translation unit. Files in no
-# group are batched alphabetically by JSON_TestUnityBatchSize.
-set(json_test_unity_groups binary)
-set(json_test_unity_group_binary binary_formats binary_utf8_error_handler binary_writer_sinks bjdata bon8 bon8-cpp17 bson byte_container_with_subtype cbor msgpack msgpack-cpp17 ubjson)
-
-if(JSON_TestUnityBuild)
-    message(STATUS "Building the unit tests in batches of ${JSON_TestUnityBatchSize} files (JSON_TestUnityBuild)")
-    json_test_add_unity_tests(FILES ${files} MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
-        BATCH_SIZE ${JSON_TestUnityBatchSize}
-        GROUPS ${json_test_unity_groups}
-        VARIANT_FILES src/unit-comparison.cpp src/unit-comparison-cpp20.cpp src/unit-class_parser.cpp src/unit-diagnostic-positions.cpp
-    )
-else()
-    foreach(file ${files})
-        json_test_add_test_for(${file} MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force})
-    endforeach()
-endif()
+foreach(file ${files})
+    json_test_add_test_for(${file} MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force})
+endforeach()

 # tests/src/unit-no-macro-leak.cpp #include-s the generated leak-check file,
 # so its test targets must be built after generate_hedley_undef_checks.
@@ -380,13 +350,6 @@ json_test_add_test_for(src/unit-comparison.cpp
    NAME test-comparison_legacy
    MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
 )
-json_test_set_test_options(test-comparison_legacy-cpp20
-    COMPILE_DEFINITIONS JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON=1
-)
-json_test_add_test_for(src/unit-comparison-cpp20.cpp
-    NAME test-comparison_legacy-cpp20
-    MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
-)

 # test the parser again with JSON_DIAGNOSTIC_POSITIONS enabled
 json_test_set_test_options(test-class_parser_diagnostic_positions
@@ -406,33 +369,6 @@ json_test_add_test_for(src/unit-diagnostic-positions.cpp
    MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
 )

-# test reading from a std::istream again without scanning the get area in bulk
-json_test_set_test_options(test-stream-bulk-scan_disabled
-    COMPILE_DEFINITIONS JSON_DISABLE_STREAM_BULK_SCAN=1
-)
-json_test_add_test_for(src/unit-stream-bulk-scan.cpp
-    NAME test-stream-bulk-scan_disabled
-    MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
-)
-
-# test reading from a std::istream again with JSON_PRECISE_STREAM_POSITION
-json_test_set_test_options(test-stream-bulk-scan_precise
-    COMPILE_DEFINITIONS JSON_PRECISE_STREAM_POSITION=1
-)
-json_test_add_test_for(src/unit-stream-bulk-scan.cpp
-    NAME test-stream-bulk-scan_precise
-    MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
-)
-
-# test reading from a FILE* again with the locking stdio functions
-json_test_set_test_options(test-file_input_unlocked_io_disabled
-    COMPILE_DEFINITIONS JSON_DISABLE_UNLOCKED_FILE_IO=1
-)
-json_test_add_test_for(src/unit-file_input.cpp
-    NAME test-file_input_unlocked_io_disabled
-    MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
-)
-
 # the json_view parser again with the portable string scanning instead of
 # NEON/SSE2, and on x86-64 with the SSSE3 UTF-8 check (JSON_VIEW_USE_SSSE3)
 json_test_set_test_options(test-json_view_builder_portable
@@ -1,92 +0,0 @@
-# Unit tests
-
-The unit tests are in [`src/unit-*.cpp`](src) and use [doctest](https://github.com/doctest/doctest). Each file becomes
-one CTest test per C++ standard it is built for, named after the file: `src/unit-foo.cpp` becomes `test-foo_cpp11`.
-
-## Build and run
-
-```sh
-cmake -S . -B build -DJSON_BuildTests=ON
-cmake --build build -j 10
-ctest --test-dir build -j 10
-```
-
-The [CMake options](../docs/mkdocs/docs/integration/cmake.md) starting with `JSON_Test` (and `JSON_FastTests`,
-`JSON_Valgrind`) control the test build. The most relevant ones:
-
- `JSON_TestStandards`: build every test file for the given standards, e.g., `-DJSON_TestStandards=17`. By default,
-  a file is built for C++11 and for each standard whose `JSON_HAS_CPP_<N>` macro it mentions (see below).
- `JSON_TestUnityBuild`: compile several test files together (see below). Set it to `OFF` to get one executable per
-  test file, e.g., to debug a single test in a debugger.
- `JSON_TestShard`: build only a part of the test files, e.g., `-DJSON_TestShard=0/2`.
-
-To run the tests of one file only, run its CTest test, e.g., `ctest --test-dir build -R test-foo_cpp11`.
-
-## How test files are built
-
-Two mechanisms keep the compile time down. Both are automatic, but they set a few rules for test files.
-
-### C++ standards
-
-A test file is built for a C++ standard beyond C++11 if its text contains `JSON_HAS_CPP_<N>`, for instance in
-`#ifdef JSON_HAS_CPP_17`, or in a comment `// JSON_HAS_CPP_17` next to code that needs a macro only defined for that
-standard, such as `JSON_HAS_FILESYSTEM`. Then the *whole file* is compiled again for that standard.
-
-So that this does not happen for the large files, tests that need C++14, C++17, or C++20 go into a separate file
-`src/unit-<name>-cpp<N>.cpp` (e.g., [`src/unit-regression3-cpp17.cpp`](src/unit-regression3-cpp17.cpp)), whose body
-is wrapped in `#ifdef JSON_HAS_CPP_<N>`. The main file `src/unit-<name>.cpp` must not mention `JSON_HAS_CPP_<N>` at
-all, not even in a comment, so it is built for C++11 only. The CI jobs `ci_test_*_cxx<N>` still build every test file
-for every standard.
-
-### Unity build
-
-With `JSON_TestUnityBuild` (`ON` by default, `OFF` with MinGW), CMake compiles several test files as one translation
-unit, so they share the template instantiations of the library. CMake generates `build/tests/unity/test-unity-*.cpp`,
-which `#include` the test files of a batch. Every test file still gets its own CTest test, which runs the batch
-executable with `--source-file=*unit-foo.cpp`, so only the test cases of that file run.
-
-CMake decides from the macros a file defines *before* including `<nlohmann/json.hpp>`:
-
-| Macros defined before the include                                                         | Built as                          |
-|-------------------------------------------------------------------------------------------|-----------------------------------|
-| none (or only `SKIP_TESTS_FOR_*` and similar macros derived from global definitions)      | batch with the other plain files  |
-| only `JSON_TESTS_PRIVATE`                                                                 | batch with the other such files   |
-| any library configuration macro (`JSON_DIAGNOSTICS`, `JSON_NO_IO`, `JSON_ASSERT`, ...)    | its own executable                |
-
-Files with test-specific build options (`json_test_set_test_options(test-foo ...)` in
-[`CMakeLists.txt`](CMakeLists.txt)) also get their own executable. The batchable files are split alphabetically into
-batches of `JSON_TestUnityBatchSize` files, except for explicit groups of related files: `json_test_unity_group_binary`
-compiles all binary-format tests together, because they share the binary readers and writers. Only add a group if it
-measurably pays off; files that share little just make one slow translation unit.
-
-## Rules for test files
-
-Because the files of a batch share one translation unit, a test file must not affect the files that follow it:
-
-1. **Give file-scope helpers file-specific names.** An anonymous namespace does not help, as the batch is one
-   translation unit. Use a name such as `my_allocator_2982`, or wrap the helpers in a namespace named after the file
-   (e.g., `namespace unit_comparison_detail`). Clashes show up as compile errors.
-2. **Do not `#undef` library macros**, such as `JSON_HAS_CPP_17`, at the end of a file: this silently disables the tests
-   that depend on them in the later files of the batch. `#undef` macros you define yourself after including the library.
-3. **Put version-dependent tests into `unit-<name>-cpp<N>.cpp`** (see [C++ standards](#c-standards)).
-4. **Define test cases in the `.cpp` file itself.** The batch executable selects the tests of a file by its name, so a
-   `TEST_CASE` in a shared header is not run. The only exception is the test case in
-   [`src/make_test_data_available.hpp`](src/make_test_data_available.hpp), which CMake handles explicitly.
-
-To check a new file for clashes with all others at once, build with `-DJSON_TestUnityBatchSize=1000`, which puts all
-batchable files of a kind into one translation unit.
-
-## Where to add tests
-
-Tests are structured along the features of the library. Usually, an existing file is the right place:
-
- For a bug fix, add a section referencing the issue to [`src/unit-regression3.cpp`](src/unit-regression3.cpp), or to
-  [`src/unit-regression3-cpp17.cpp`](src/unit-regression3-cpp17.cpp) /
-  [`src/unit-regression3-cpp20.cpp`](src/unit-regression3-cpp20.cpp) if the test needs C++17 / C++20.
-  [`src/unit-regression2.cpp`](src/unit-regression2.cpp) holds older tests and should not grow further.
- When testing exceptions, use `CHECK_THROWS_WITH_AS`, which also checks the `what()` message.
-
-A new file `src/unit-<name>.cpp` is picked up automatically when CMake runs again; no change to `CMakeLists.txt` is
-needed.
-
-See also [`fuzzing.md`](fuzzing.md) for fuzz testing.
@@ -22,8 +22,6 @@ foreach(test default noversion)
        JSON_DIAGNOSTICS=1
        JSON_DIAGNOSTIC_POSITIONS=1
        JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON=1
-        JSON_DISABLE_STREAM_BULK_SCAN=1
-        JSON_DISABLE_UNLOCKED_FILE_IO=1
        JSON_VIEW_NO_SIMD
        JSON_VIEW_USE_SSSE3)
    target_link_libraries(abi_config_${test}_all_tags PRIVATE abi_compat_main)
@@ -52,14 +52,6 @@ TEST_CASE("default namespace")
        expected += "_ekmo";
 #endif

-#if JSON_DISABLE_STREAM_BULK_SCAN
-        expected += "_dsbs";
-#endif
-
-#if JSON_DISABLE_UNLOCKED_FILE_IO
-        expected += "_dufio";
-#endif
-
 #ifdef JSON_VIEW_NO_SIMD
        expected += "_vns";
 #endif
@@ -53,14 +53,6 @@ TEST_CASE("default namespace without version component")
        expected += "_ekmo";
 #endif

-#if JSON_DISABLE_STREAM_BULK_SCAN
-        expected += "_dsbs";
-#endif
-
-#if JSON_DISABLE_UNLOCKED_FILE_IO
-        expected += "_dufio";
-#endif
-
 #ifdef JSON_VIEW_NO_SIMD
        expected += "_vns";
 #endif
@@ -8,13 +8,11 @@

 #include <benchmark/benchmark.h>
 #include <nlohmann/json.hpp>
-#include <array>
-#include <cstdio>
-#include <deque>
 #include <fstream>
+#include <array>
+#include <deque>
 #include <numeric>
 #include <set>
-#include <sstream>
 #include <vector>
 #include <test_data.hpp>

@@ -53,65 +51,6 @@ BENCHMARK_CAPTURE(ParseFile, signed_ints,       TEST_DATA_DIRECTORY "/regression
 BENCHMARK_CAPTURE(ParseFile, unsigned_ints,     TEST_DATA_DIRECTORY "/regression/unsigned_ints.json");
 BENCHMARK_CAPTURE(ParseFile, small_signed_ints, TEST_DATA_DIRECTORY "/regression/small_signed_ints.json");

-//////////////////////////////////////////////////////////////////////////////
-// parse JSON from a FILE*
-//////////////////////////////////////////////////////////////////////////////
-
-static void ParseFILE(benchmark::State& state, const char* filename)
-{
-    while (state.KeepRunning())
-    {
-        state.PauseTiming();
-        std::FILE* f = std::fopen(filename, "rb");
-        auto* j = new json();
-        state.ResumeTiming();
-
-        *j = json::parse(f);
-
-        state.PauseTiming();
-        std::fclose(f);
-        delete j;
-        state.ResumeTiming();
-    }
-
-    std::ifstream file(filename, std::ios::binary | std::ios::ate);
-    state.SetBytesProcessed(state.iterations() * file.tellg());
-}
-BENCHMARK_CAPTURE(ParseFILE, canada,       TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
-BENCHMARK_CAPTURE(ParseFILE, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(ParseFILE, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-//////////////////////////////////////////////////////////////////////////////
-// read many small values from one stream (NDJSON)
-//////////////////////////////////////////////////////////////////////////////
-
-static void ParseStreamValues(benchmark::State& state, bool numbers)
-{
-    std::string input;
-    for (int i = 0; i < 10000; ++i)
-    {
-        input += numbers ? std::to_string(i * 7919) + " "
-                 : R"({"id":)" + std::to_string(i) + R"(,"name":"user)" + std::to_string(i) + R"(","active":true,"score":)" + std::to_string(i * 0.25) + "}\n";
-    }
-
-    for (auto _ : state)
-    {
-        std::istringstream is(input);
-        json j;
-        std::size_t count = 0;
-        while (!(is >> std::ws).eof())
-        {
-            is >> j;
-            ++count;
-        }
-        benchmark::DoNotOptimize(count);
-    }
-
-    state.SetBytesProcessed(static_cast<int64_t>(state.iterations() * input.size()));
-}
-BENCHMARK_CAPTURE(ParseStreamValues, ndjson,  false);
-BENCHMARK_CAPTURE(ParseStreamValues, numbers, true);
-
 //////////////////////////////////////////////////////////////////////////////
 // parse JSON from string
 //////////////////////////////////////////////////////////////////////////////
@@ -1,98 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-// This file contains the C++17-only part of unit-allocator.cpp (std::string_view key
-// lookup with a failing allocator). It is kept in a separate translation unit so the (much
-// larger) unit-allocator.cpp is built for C++11 only and not rebuilt for every C++
-// standard.
-
-#include "doctest_compatibility.h"
-
-#include <nlohmann/json.hpp>
-
-#ifdef JSON_HAS_CPP_17
-#include <memory>
-#include <new>
-#include <string_view>
-#include <utility>
-
-namespace
-{
-bool next_construct_fails_cpp17 = false;
-bool next_destroy_fails_cpp17 = false;
-bool next_deallocate_fails_cpp17 = false;
-
-template<class T>
-struct my_allocator_cpp17 : std::allocator<T>
-{
-    using std::allocator<T>::allocator;
-
-    template<class... Args>
-    void construct(T* p, Args&& ... args)
-    {
-        if (next_construct_fails_cpp17)
-        {
-            next_construct_fails_cpp17 = false;
-            throw std::bad_alloc();
-        }
-
-        ::new (reinterpret_cast<void*>(p)) T(std::forward<Args>(args)...);
-    }
-
-    void deallocate(T* p, std::size_t n)
-    {
-        if (next_deallocate_fails_cpp17)
-        {
-            next_deallocate_fails_cpp17 = false;
-            throw std::bad_alloc();
-        }
-
-        std::allocator<T>::deallocate(p, n);
-    }
-
-    void destroy(T* p)
-    {
-        if (next_destroy_fails_cpp17)
-        {
-            next_destroy_fails_cpp17 = false;
-            throw std::bad_alloc();
-        }
-
-        static_cast<void>(p); // fix MSVC's C4100 warning
-        p->~T();
-    }
-
-    template <class U>
-    struct rebind
-    {
-        using other = my_allocator_cpp17<U>;
-    };
-};
-} // namespace
-
-// the no-exceptions CI job skips every CHECK_THROWS_AS, which would leave
-// next_construct_fails_cpp17 set for the next allocation outside a check
-#if !defined(JSON_NOEXCEPTION)
-TEST_CASE("a failed allocation leaves the value unchanged (C++17)")
-{
-    // create JSON type using the throwing allocator
-    using my_json = nlohmann::json::with_allocator_t<my_allocator_cpp17>;
-
-    SECTION("turning a null value into an array or object")
-    {
-        my_json j;
-
-        next_construct_fails_cpp17 = true;
-        CHECK_THROWS_AS(j[std::string_view("key")], std::bad_alloc&);
-        CHECK(j.is_null());
-
-        next_construct_fails_cpp17 = false;
-    }
-}
-#endif
-#endif
@@ -1,115 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-// This file contains the C++20-only part of unit-allocator.cpp (creating a value from a
-// std::ranges view with a failing allocator). It is kept in a separate translation unit so
-// the (much larger) unit-allocator.cpp is built for C++11 only and not rebuilt for every
-// C++ standard.
-
-#include "doctest_compatibility.h"
-
-#include <nlohmann/json.hpp>
-
-#ifdef JSON_HAS_CPP_20
-#if JSON_HAS_RANGES
-    #include <ranges>
-#endif
-
-#include <memory>
-#include <new>
-#include <utility>
-#include <vector>
-
-namespace
-{
-bool next_construct_fails_cpp20 = false;
-bool next_destroy_fails_cpp20 = false;
-bool next_deallocate_fails_cpp20 = false;
-
-template<class T>
-struct my_allocator_cpp20 : std::allocator<T>
-{
-    using std::allocator<T>::allocator;
-
-    template<class... Args>
-    void construct(T* p, Args&& ... args)
-    {
-        if (next_construct_fails_cpp20)
-        {
-            next_construct_fails_cpp20 = false;
-            throw std::bad_alloc();
-        }
-
-        ::new (reinterpret_cast<void*>(p)) T(std::forward<Args>(args)...);
-    }
-
-    void deallocate(T* p, std::size_t n)
-    {
-        if (next_deallocate_fails_cpp20)
-        {
-            next_deallocate_fails_cpp20 = false;
-            throw std::bad_alloc();
-        }
-
-        std::allocator<T>::deallocate(p, n);
-    }
-
-    void destroy(T* p)
-    {
-        if (next_destroy_fails_cpp20)
-        {
-            next_destroy_fails_cpp20 = false;
-            throw std::bad_alloc();
-        }
-
-        static_cast<void>(p); // fix MSVC's C4100 warning
-        p->~T();
-    }
-
-    template <class U>
-    struct rebind
-    {
-        using other = my_allocator_cpp20<U>;
-    };
-};
-} // namespace
-
-// the no-exceptions CI job skips every CHECK_THROWS_AS, which would leave
-// next_construct_fails_cpp20 set for the next allocation outside a check
-#if !defined(JSON_NOEXCEPTION)
-TEST_CASE("a failed allocation leaves the value unchanged (C++20)")
-{
-    // create JSON type using the throwing allocator
-    using my_json = nlohmann::json::with_allocator_t<my_allocator_cpp20>;
-
-    // With iterator debugging, VS 2015's containers construct a proxy with the
-    // allocator in constructors that cannot report its failure, so a failing
-    // allocator crashes this section there (SIGSEGV with VS 2015 Debug x86).
-#if !(defined(_MSC_VER) && _MSC_VER < 1910 && defined(_ITERATOR_DEBUG_LEVEL) && _ITERATOR_DEBUG_LEVEL > 0)
-    SECTION("converting into an existing value")
-    {
-        // to_json replaces the value it is given; the old one must survive a
-        // failed creation of the new one
-        my_json j = "old";
-
-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-        const std::vector<int> numbers = {1, 2};
-        next_construct_fails_cpp20 = true;
-        CHECK_THROWS_AS(nlohmann::to_json(j, numbers | std::views::filter([](int /*unused*/)
-        {
-            return true;
-        })), std::bad_alloc&);
-        CHECK(j == "old");
-#endif
-
-        next_construct_fails_cpp20 = false;
-    }
-#endif
-}
-#endif
-#endif
@@ -13,6 +13,9 @@
 using nlohmann::json;

 #include <valarray>
+#if JSON_HAS_RANGES
+    #include <ranges>
+#endif

 namespace
 {
@@ -681,6 +684,12 @@ TEST_CASE("a failed allocation leaves the value unchanged")
        CHECK_THROWS_AS(j["key"], std::bad_alloc&);
        CHECK(j.is_null());

+#ifdef JSON_HAS_CPP_17
+        next_construct_fails = true;
+        CHECK_THROWS_AS(j[std::string_view("key")], std::bad_alloc&);
+        CHECK(j.is_null());
+#endif
+
        next_construct_fails = true;
        CHECK_THROWS_AS(j.push_back(my_json(1)), std::bad_alloc&);
        CHECK(j.is_null());
@@ -778,6 +787,16 @@ TEST_CASE("a failed allocation leaves the value unchanged")
        CHECK_THROWS_AS(nlohmann::to_json(j, std::valarray<int> {1, 2}), std::bad_alloc&);
        CHECK(j == "old");

+#if JSON_HAS_RANGES && !defined(__MINGW32__)
+        const std::vector<int> numbers = {1, 2};
+        next_construct_fails = true;
+        CHECK_THROWS_AS(nlohmann::to_json(j, numbers | std::views::filter([](int /*unused*/)
+        {
+            return true;
+        })), std::bad_alloc&);
+        CHECK(j == "old");
+#endif
+
        next_construct_fails = false;
        nlohmann::to_json(j, std::vector<int> {1, 2});
        CHECK(j == my_json({1, 2}));
@@ -11,10 +11,8 @@
 #include <nlohmann/json.hpp>
 using nlohmann::json;

-#include <array>
 #include <cstdint>
 #include <limits>
-#include <sstream>
 #include <string>
 #include <vector>

@@ -37,17 +35,6 @@ std::vector<json> test_values()
        big_object[std::to_string(i)] = i;
    }

-    // large strings and binary values between small ones: a write too large
-    // for the space the vector sink has ahead takes a different path than a
-    // small one, and the small writes after it must still land behind it
-    json large_payloads = json::array();
-    for (int i = 0; i < 50; ++i)
-    {
-        large_payloads.push_back(std::string(300, static_cast<char>('a' + (i % 26))));
-        large_payloads.push_back(i);
-        large_payloads.push_back(json::binary(std::vector<std::uint8_t>(static_cast<std::size_t>(100 * i), static_cast<std::uint8_t>(i))));
-    }
-
    return
    {
        json(nullptr), json(true), json(false),
@@ -59,23 +46,10 @@ std::vector<json> test_values()
        json::array(), json::object(),
        json::array({1, 2, 3}), json({{"a", 1}, {"b", nullptr}}),
        json({{"nested", {{"deep", json::array({1, "two", 3.0, nullptr})}}}}),
-        big_array, big_object, large_payloads,
-        json::binary(std::vector<std::uint8_t>(5000, 0x42))
+        big_array, big_object
    };
 }

-// explicit char -> uint8_t conversion (the iterator-range constructor converts implicitly, which -fsanitize=integer flags)
-std::vector<std::uint8_t> to_bytes(const std::string& str)
-{
-    std::vector<std::uint8_t> result;
-    result.reserve(str.size());
-    for (const char c : str)
-    {
-        result.push_back(static_cast<std::uint8_t>(c));
-    }
-    return result;
-}
-
 // BON8 has no integers above the int64 range, so to_bon8() rejects them
 bool bon8_representable(const json& j)
 {
@@ -196,258 +170,6 @@ TEST_CASE("binary writer output sinks")
    }
 }

-namespace
-{
-
-// the CBOR head of an integer, encoded independently of binary_writer
-void reference_cbor_head(std::vector<std::uint8_t>& out, const std::uint8_t major_type, const std::uint64_t argument)
-{
-    if (argument <= 23)
-    {
-        out.push_back(static_cast<std::uint8_t>(major_type + argument));
-        return;
-    }
-
-    int length = 8;
-    std::uint8_t additional = 27;
-    if (argument <= 0xFF)
-    {
-        length = 1;
-        additional = 24;
-    }
-    else if (argument <= 0xFFFF)
-    {
-        length = 2;
-        additional = 25;
-    }
-    else if (argument <= 0xFFFFFFFF)
-    {
-        length = 4;
-        additional = 26;
-    }
-
-    out.push_back(static_cast<std::uint8_t>(major_type + additional));
-    for (int i = length - 1; i >= 0; --i)
-    {
-        out.push_back(static_cast<std::uint8_t>(argument >> (8 * i)));
-    }
-}
-
-// the CBOR encoding of an integer value
-void reference_cbor_integer(std::vector<std::uint8_t>& out, const json& j)
-{
-    if (j.is_number_unsigned())
-    {
-        reference_cbor_head(out, 0x00, j.get<std::uint64_t>());
-        return;
-    }
-
-    const auto n = j.get<std::int64_t>();
-    if (n >= 0)
-    {
-        reference_cbor_head(out, 0x00, static_cast<std::uint64_t>(n));
-    }
-    else
-    {
-        reference_cbor_head(out, 0x20, static_cast<std::uint64_t>(-1 - n));
-    }
-}
-
-// the MessagePack encoding of an integer value, encoded independently of
-// binary_writer
-void reference_msgpack_integer(std::vector<std::uint8_t>& out, const json& j)
-{
-    const auto put = [&out](const std::uint8_t marker, const std::uint64_t bits, const int length)
-    {
-        out.push_back(marker);
-        for (int i = length - 1; i >= 0; --i)
-        {
-            out.push_back(static_cast<std::uint8_t>(bits >> (8 * i)));
-        }
-    };
-
-    if (j.is_number_unsigned() || j.get<std::int64_t>() >= 0)
-    {
-        const auto u = j.get<std::uint64_t>();
-        if (u < 128)
-        {
-            out.push_back(static_cast<std::uint8_t>(u));
-        }
-        else if (u <= 0xFF)
-        {
-            put(0xCC, u, 1);
-        }
-        else if (u <= 0xFFFF)
-        {
-            put(0xCD, u, 2);
-        }
-        else if (u <= 0xFFFFFFFF)
-        {
-            put(0xCE, u, 4);
-        }
-        else
-        {
-            put(0xCF, u, 8);
-        }
-        return;
-    }
-
-    const auto n = j.get<std::int64_t>();
-    const auto bits = static_cast<std::uint64_t>(n);
-    if (n >= -32)
-    {
-        out.push_back(static_cast<std::uint8_t>(bits));
-    }
-    else if (n >= -128)
-    {
-        put(0xD0, bits, 1);
-    }
-    else if (n >= -32768)
-    {
-        put(0xD1, bits, 2);
-    }
-    else if (n >= -2147483648LL)
-    {
-        put(0xD2, bits, 4);
-    }
-    else
-    {
-        put(0xD3, bits, 8);
-    }
-}
-
-// integers at every boundary of the CBOR and MessagePack sizes, signed and
-// unsigned
-std::vector<json> boundary_integers()
-{
-    std::vector<json> result;
-    const std::array<std::uint64_t, 38> boundaries =
-    {
-        {
-            0, 1, 22, 23, 24, 25, 31, 32, 33, 126, 127, 128, 129, 254, 255, 256, 257,
-            32766, 32767, 32768, 32769, 65534, 65535, 65536, 65537,
-            2147483646ULL, 2147483647ULL, 2147483648ULL, 2147483649ULL,
-            4294967294ULL, 4294967295ULL, 4294967296ULL, 4294967297ULL,
-            9223372036854775806ULL, 9223372036854775807ULL, 9223372036854775808ULL,
-            18446744073709551614ULL, 18446744073709551615ULL
-        }
-    };
-    for (const std::uint64_t u : boundaries)
-    {
-        result.emplace_back(u);
-        if (u <= static_cast<std::uint64_t>((std::numeric_limits<std::int64_t>::max)()))
-        {
-            const auto n = static_cast<std::int64_t>(u);
-            result.emplace_back(n);
-            result.emplace_back(-n);
-            result.emplace_back(-n - 1);
-        }
-    }
-    return result;
-}
-
-} // namespace
-
-// Arrays of integers are written in runs straight into space reserved from the
-// sink, with branch-free encodings; check them against independent encoders for
-// runs shorter and longer than one reservation, broken up by other values, and
-// through each sink.
-TEST_CASE("CBOR and MessagePack integer arrays")
-{
-    const std::vector<json> integers = boundary_integers();
-
-    for (const std::size_t length :
-            {
-                std::size_t{1}, std::size_t{27}, std::size_t{28}, std::size_t{29}, std::size_t{57}, std::size_t{1000}
-            })
-    {
-        for (const std::size_t break_every :
-                {
-                    std::size_t{0}, std::size_t{1}, std::size_t{7}, std::size_t{28}
-                })
-        {
-            CAPTURE(length)
-            CAPTURE(break_every)
-
-            json array = json::array();
-            std::vector<std::uint8_t> expected_cbor;
-            std::vector<std::uint8_t> expected_msgpack;
-            for (std::size_t i = 0; i < length; ++i)
-            {
-                if (break_every != 0 && i % (break_every + 1) == break_every)
-                {
-                    array.push_back("x");
-                    expected_cbor.push_back(0x61);
-                    expected_cbor.push_back('x');
-                    expected_msgpack.push_back(0xA1);
-                    expected_msgpack.push_back('x');
-                }
-                else
-                {
-                    const json& value = integers[(i * 7) % integers.size()];
-                    array.push_back(value);
-                    reference_cbor_integer(expected_cbor, value);
-                    reference_msgpack_integer(expected_msgpack, value);
-                }
-            }
-
-            std::vector<std::uint8_t> head;
-            reference_cbor_head(head, 0x80, length);
-            expected_cbor.insert(expected_cbor.begin(), head.begin(), head.end());
-
-            head.clear();
-            if (length <= 15)
-            {
-                head.push_back(static_cast<std::uint8_t>(0x90 + length));
-            }
-            else
-            {
-                head = {0xDC, static_cast<std::uint8_t>(length >> 8), static_cast<std::uint8_t>(length)};
-            }
-            expected_msgpack.insert(expected_msgpack.begin(), head.begin(), head.end());
-
-            CHECK(json::to_cbor(array) == expected_cbor);
-            CHECK(json::to_msgpack(array) == expected_msgpack);
-
-            std::vector<std::uint8_t> through_adapter = {0xAA};
-            json::to_cbor(array, through_adapter);
-            CHECK(std::vector<std::uint8_t>(through_adapter.begin() + 1, through_adapter.end()) == expected_cbor);
-            through_adapter = {0xAA};
-            json::to_msgpack(array, through_adapter);
-            CHECK(std::vector<std::uint8_t>(through_adapter.begin() + 1, through_adapter.end()) == expected_msgpack);
-
-            std::ostringstream stream;
-            json::to_cbor(array, stream);
-            std::string streamed = stream.str();
-            CHECK(to_bytes(streamed) == expected_cbor);
-            stream.str("");
-            json::to_msgpack(array, stream);
-            streamed = stream.str();
-            CHECK(to_bytes(streamed) == expected_msgpack);
-
-            CHECK(json::from_cbor(expected_cbor) == array);
-            CHECK(json::from_msgpack(expected_msgpack) == array);
-
-            // the same array as object members
-            const json object = {{"a", array}, {"b", array}};
-            CHECK(json::from_cbor(json::to_cbor(object)) == object);
-            CHECK(json::from_msgpack(json::to_msgpack(object)) == object);
-        }
-    }
-
-    // single values, outside an array
-    for (const auto& value : integers)
-    {
-        CAPTURE(value)
-        std::vector<std::uint8_t> expected;
-        reference_cbor_integer(expected, value);
-        CHECK(json::to_cbor(value) == expected);
-        expected.clear();
-        reference_msgpack_integer(expected, value);
-        CHECK(json::to_msgpack(value) == expected);
-    }
-}
-
 // binary_reserve_hint() is documented as a *lower* bound on the serialized size,
 // so that reserving it up front can never leave the returned vector holding
 // capacity beyond what the value actually needs.
@@ -1,60 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-// This file contains the C++17-only part of unit-bon8.cpp (BON8 with std::byte
-// containers). It is kept in a separate translation unit so the (much larger) unit-
-// bon8.cpp is built for C++11 only and not rebuilt for every C++ standard.
-
-#include "doctest_compatibility.h"
-
-#include <nlohmann/json.hpp>
-using nlohmann::json;
-
-#ifdef JSON_HAS_CPP_17
-#include <cstddef>
-#include <cstdint>
-#include <vector>
-
-TEST_CASE("BON8 with std::byte")
-{
-    SECTION("vector roundtrip")
-    {
-        const json original =
-        {
-            {"name", "test"},
-            {"value", 42},
-            {"array", {1, 2, 3}}
-        };
-
-        const std::vector<uint8_t> temp = json::to_bon8(original);
-        std::vector<std::byte> bon8_data(temp.size());
-        for (size_t i = 0; i < temp.size(); ++i)
-        {
-            bon8_data[i] = std::byte(temp[i]);
-        }
-
-        json from_bytes;
-        CHECK_NOTHROW(from_bytes = json::from_bon8(bon8_data));
-        CHECK(from_bytes == original);
-    }
-
-    SECTION("empty vector")
-    {
-        const std::vector<std::byte> empty_data;
-        CHECK_THROWS_WITH_AS([&]()
-        {
-            [[maybe_unused]] auto result = json::from_bon8(empty_data);
-            return true;
-        }
-        (),
-        "[json.exception.parse_error.110] parse error at byte 1: syntax error while parsing BON8 value: unexpected end of input",
-        json::parse_error&);
-    }
-}
-
-#endif
@@ -1099,3 +1099,41 @@ TEST_CASE("issue #5648 - from_bon8(ptr, len) must read len bytes, not treat ptr
 #endif
 }

+#ifdef JSON_HAS_CPP_17
+TEST_CASE("BON8 with std::byte")
+{
+    SECTION("vector roundtrip")
+    {
+        const json original =
+        {
+            {"name", "test"},
+            {"value", 42},
+            {"array", {1, 2, 3}}
+        };
+
+        const std::vector<uint8_t> temp = json::to_bon8(original);
+        std::vector<std::byte> bon8_data(temp.size());
+        for (size_t i = 0; i < temp.size(); ++i)
+        {
+            bon8_data[i] = std::byte(temp[i]);
+        }
+
+        json from_bytes;
+        CHECK_NOTHROW(from_bytes = json::from_bon8(bon8_data));
+        CHECK(from_bytes == original);
+    }
+
+    SECTION("empty vector")
+    {
+        const std::vector<std::byte> empty_data;
+        CHECK_THROWS_WITH_AS([&]()
+        {
+            [[maybe_unused]] auto result = json::from_bon8(empty_data);
+            return true;
+        }
+        (),
+        "[json.exception.parse_error.110] parse error at byte 1: syntax error while parsing BON8 value: unexpected end of input",
+        json::parse_error&);
+    }
+}
+#endif
@@ -1,526 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-// This file contains the C++20-only part of unit-comparison.cpp (tests of operator<=> and
-// other three-way comparison specific behavior). It is kept in a separate translation unit
-// so the (much larger) unit-comparison.cpp is built for C++11 only and not rebuilt for
-// every C++ standard.
-
-#include "doctest_compatibility.h"
-
-#include <nlohmann/json.hpp>
-using nlohmann::json;
-
-#ifdef JSON_HAS_CPP_20
-#if JSON_HAS_THREE_WAY_COMPARISON
-#include <cmath>
-#include <compare>
-#include <cstddef>
-#include <limits>
-#include <string>
-#include <utility>
-#include <vector>
-
-// this can be replaced with the doctest stl extension header in version 2.5
-namespace doctest
-{
-template<> struct StringMaker<std::partial_ordering>
-{
-    static String convert(const std::partial_ordering& order)
-    {
-        if (order == std::partial_ordering::less)
-        {
-            return "std::partial_ordering::less";
-        }
-        if (order == std::partial_ordering::equivalent)
-        {
-            return "std::partial_ordering::equivalent";
-        }
-        if (order == std::partial_ordering::greater)
-        {
-            return "std::partial_ordering::greater";
-        }
-        if (order == std::partial_ordering::unordered)
-        {
-            return "std::partial_ordering::unordered";
-        }
-        return "{?}";
-    }
-};
-} // namespace doctest
-
-TEST_CASE("lexicographical comparison operators (C++20)")
-{
-    constexpr auto f_ = false;
-    constexpr auto _t = true;
-    constexpr auto nan = std::numeric_limits<json::number_float_t>::quiet_NaN();
-    constexpr auto lt = std::partial_ordering::less;
-    constexpr auto gt = std::partial_ordering::greater;
-    constexpr auto eq = std::partial_ordering::equivalent;
-    constexpr auto un = std::partial_ordering::unordered;
-
-    INFO("using 3-way comparison");
-
-#if JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON
-    INFO("using legacy comparison");
-#endif
-
-    SECTION("types")
-    {
-        std::vector<json::value_t> j_types =
-        {
-            json::value_t::null,
-            json::value_t::boolean,
-            json::value_t::number_integer,
-            json::value_t::number_unsigned,
-            json::value_t::number_float,
-            json::value_t::object,
-            json::value_t::array,
-            json::value_t::string,
-            json::value_t::binary,
-            json::value_t::discarded
-        };
-
-        std::vector<std::vector<bool>> expected_lt =
-        {
-            //0   1   2   3   4   5   6   7   8   9
-            {f_, _t, _t, _t, _t, _t, _t, _t, _t, f_}, //  0
-            {f_, f_, _t, _t, _t, _t, _t, _t, _t, f_}, //  1
-            {f_, f_, f_, f_, f_, _t, _t, _t, _t, f_}, //  2
-            {f_, f_, f_, f_, f_, _t, _t, _t, _t, f_}, //  3
-            {f_, f_, f_, f_, f_, _t, _t, _t, _t, f_}, //  4
-            {f_, f_, f_, f_, f_, f_, _t, _t, _t, f_}, //  5
-            {f_, f_, f_, f_, f_, f_, f_, _t, _t, f_}, //  6
-            {f_, f_, f_, f_, f_, f_, f_, f_, _t, f_}, //  7
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, //  8
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, //  9
-        };
-
-        SECTION("comparison: less")
-        {
-            for (size_t i = 0; i < j_types.size(); ++i)
-            {
-                for (size_t j = 0; j < j_types.size(); ++j)
-                {
-                    CAPTURE(i)
-                    CAPTURE(j)
-                    // check precomputed values
-                    CHECK((j_types[i] < j_types[j]) == expected_lt[i][j]);
-                }
-            }
-        }
-
-        SECTION("comparison: 3-way")
-        {
-            // doctest runs the REQUIRE in the test case body once per leaf section; keep it
-            // here to run it as often as before the 3-way sections moved from unit-comparison.cpp
-            REQUIRE(std::isnan(nan));
-
-            std::vector<std::vector<std::partial_ordering>> expected =
-            {
-                //0   1   2   3   4   5   6   7   8   9
-                {eq, lt, lt, lt, lt, lt, lt, lt, lt, un}, //  0
-                {gt, eq, lt, lt, lt, lt, lt, lt, lt, un}, //  1
-                {gt, gt, eq, eq, eq, lt, lt, lt, lt, un}, //  2
-                {gt, gt, eq, eq, eq, lt, lt, lt, lt, un}, //  3
-                {gt, gt, eq, eq, eq, lt, lt, lt, lt, un}, //  4
-                {gt, gt, gt, gt, gt, eq, lt, lt, lt, un}, //  5
-                {gt, gt, gt, gt, gt, gt, eq, lt, lt, un}, //  6
-                {gt, gt, gt, gt, gt, gt, gt, eq, lt, un}, //  7
-                {gt, gt, gt, gt, gt, gt, gt, gt, eq, un}, //  8
-                {un, un, un, un, un, un, un, un, un, un}, //  9
-            };
-
-            // check expected partial_ordering against expected boolean
-            REQUIRE(expected.size() == expected_lt.size());
-            for (size_t i = 0; i < expected.size(); ++i)
-            {
-                REQUIRE(expected[i].size() == expected_lt[i].size());
-                for (size_t j = 0; j < expected[i].size(); ++j)
-                {
-                    CAPTURE(i)
-                    CAPTURE(j)
-                    CHECK(std::is_lt(expected[i][j]) == expected_lt[i][j]);
-                }
-            }
-
-            // check 3-way comparison against expected partial_ordering
-            REQUIRE(expected.size() == j_types.size());
-            for (size_t i = 0; i < j_types.size(); ++i)
-            {
-                REQUIRE(expected[i].size() == j_types.size());
-                for (size_t j = 0; j < j_types.size(); ++j)
-                {
-                    CAPTURE(i)
-                    CAPTURE(j)
-                    CHECK((j_types[i] <=> j_types[j]) == expected[i][j]); // *NOPAD*
-                }
-            }
-        }
-    }
-
-    SECTION("values")
-    {
-        json j_values =
-        {
-            nullptr, nullptr,                                              // 0 1
-            -17, 42,                                                       // 2 3
-            8u, 13u,                                                       // 4 5
-            3.14159, 23.42,                                                // 6 7
-            nan, nan,                                                      // 8 9
-            "foo", "bar",                                                  // 10 11
-            true, false,                                                   // 12 13
-            {1, 2, 3}, {"one", "two", "three"},                            // 14 15
-            {{"first", 1}, {"second", 2}}, {{"a", "A"}, {"b", {"B"}}},     // 16 17
-            json::binary({1, 2, 3}), json::binary({1, 2, 4}),              // 18 19
-            json(json::value_t::discarded), json(json::value_t::discarded) // 20 21
-        };
-
-        std::vector<std::vector<bool>> expected_eq =
-        {
-            //0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15  16  17  18  19  20  21
-            {_t, _t, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, //  0
-            {_t, _t, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, //  1
-            {f_, f_, _t, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, //  2
-            {f_, f_, f_, _t, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, //  3
-            {f_, f_, f_, f_, _t, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, //  4
-            {f_, f_, f_, f_, f_, _t, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, //  5
-            {f_, f_, f_, f_, f_, f_, _t, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, //  6
-            {f_, f_, f_, f_, f_, f_, f_, _t, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, //  7
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, //  8
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, //  9
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, // 10
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, // 11
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, f_, f_, f_, f_, f_, f_, f_, f_, f_}, // 12
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, f_, f_, f_, f_, f_, f_, f_, f_}, // 13
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, f_, f_, f_, f_, f_, f_, f_}, // 14
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, f_, f_, f_, f_, f_, f_}, // 15
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, f_, f_, f_, f_, f_}, // 16
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, f_, f_, f_, f_}, // 17
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, f_, f_, f_}, // 18
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, f_, f_}, // 19
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, // 20
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, // 21
-        };
-
-        std::vector<std::vector<bool>> expected_lt =
-        {
-            //0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15  16  17  18  19  20  21
-            {f_, f_, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, f_, f_}, //  0
-            {f_, f_, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, f_, f_}, //  1
-            {f_, f_, f_, _t, _t, _t, _t, _t, f_, f_, _t, _t, f_, f_, _t, _t, _t, _t, _t, _t, f_, f_}, //  2
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, _t, f_, f_, _t, _t, _t, _t, _t, _t, f_, f_}, //  3
-            {f_, f_, f_, _t, f_, _t, f_, _t, f_, f_, _t, _t, f_, f_, _t, _t, _t, _t, _t, _t, f_, f_}, //  4
-            {f_, f_, f_, _t, f_, f_, f_, _t, f_, f_, _t, _t, f_, f_, _t, _t, _t, _t, _t, _t, f_, f_}, //  5
-            {f_, f_, f_, _t, _t, _t, f_, _t, f_, f_, _t, _t, f_, f_, _t, _t, _t, _t, _t, _t, f_, f_}, //  6
-            {f_, f_, f_, _t, f_, f_, f_, f_, f_, f_, _t, _t, f_, f_, _t, _t, _t, _t, _t, _t, f_, f_}, //  7
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, _t, f_, f_, _t, _t, _t, _t, _t, _t, f_, f_}, //  8
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, _t, f_, f_, _t, _t, _t, _t, _t, _t, f_, f_}, //  9
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, _t, f_, f_}, // 10
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, f_, f_, f_, f_, f_, f_, f_, _t, _t, f_, f_}, // 11
-            {f_, f_, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, f_, f_, _t, _t, _t, _t, _t, _t, f_, f_}, // 12
-            {f_, f_, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, _t, f_, _t, _t, _t, _t, _t, _t, f_, f_}, // 13
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, _t, f_, f_, f_, _t, f_, f_, _t, _t, f_, f_}, // 14
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, _t, f_, f_, f_, f_, f_, f_, _t, _t, f_, f_}, // 15
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, _t, f_, f_, _t, _t, f_, f_, _t, _t, f_, f_}, // 16
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, _t, f_, f_, _t, _t, _t, f_, _t, _t, f_, f_}, // 17
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, _t, f_, f_}, // 18
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, // 19
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, // 20
-            {f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_, f_}, // 21
-        };
-
-        SECTION("signed/unsigned mixed comparison above INT64_MAX")
-        {
-            const json above_int64_max = static_cast<std::uint64_t>((std::numeric_limits<std::int64_t>::max)()) + 1ULL;
-            const json max_uint64 = (std::numeric_limits<std::uint64_t>::max)();
-            const json negative_one = -1;
-            const json one = 1;
-            const json max_int64 = (std::numeric_limits<std::int64_t>::max)();
-
-            CHECK((negative_one <=> above_int64_max) == std::partial_ordering::less); // *NOPAD*
-            CHECK((above_int64_max <=> negative_one) == std::partial_ordering::greater); // *NOPAD*
-            CHECK((negative_one <=> max_uint64) == std::partial_ordering::less); // *NOPAD*
-            CHECK((max_uint64 <=> negative_one) == std::partial_ordering::greater); // *NOPAD*
-            CHECK((one <=> above_int64_max) == std::partial_ordering::less); // *NOPAD*
-            CHECK((above_int64_max <=> one) == std::partial_ordering::greater); // *NOPAD*
-            CHECK((max_int64 <=> above_int64_max) == std::partial_ordering::less); // *NOPAD*
-            CHECK((above_int64_max <=> max_int64) == std::partial_ordering::greater); // *NOPAD*
-        }
-
-        SECTION("integer/float mixed comparison is exact")
-        {
-            // Widening the integer to a double loses precision past the
-            // mantissa, so 2^63-2 and 2^63-1 both used to compare equal to the
-            // double 2^63 while differing from each other. That makes equality
-            // intransitive and the ordering not a strict weak ordering.
-            const json below_two_63 = static_cast<std::int64_t>(9223372036854775806LL);
-            const json max_int64 = (std::numeric_limits<std::int64_t>::max)();
-            const json two_63 = 9223372036854775808.0;
-
-            // the same past the unsigned range
-            const json max_uint64 = (std::numeric_limits<std::uint64_t>::max)();
-            const json two_64 = 18446744073709551616.0;
-
-            CHECK((max_int64 <=> two_63) == std::partial_ordering::less); // *NOPAD*
-            CHECK((two_63 <=> max_int64) == std::partial_ordering::greater); // *NOPAD*
-            CHECK((below_two_63 <=> max_int64) == std::partial_ordering::less); // *NOPAD*
-            CHECK((max_uint64 <=> two_64) == std::partial_ordering::less); // *NOPAD*
-            CHECK((json(1) <=> json(1.0)) == std::partial_ordering::equivalent); // *NOPAD*
-            CHECK((json(1) <=> json(nan)) == std::partial_ordering::unordered); // *NOPAD*
-        }
-
-        SECTION("comparison: 3-way")
-        {
-            // doctest runs the REQUIRE in the test case body once per leaf section; keep it
-            // here to run it as often as before the 3-way sections moved from unit-comparison.cpp
-            REQUIRE(std::isnan(nan));
-
-            std::vector<std::vector<std::partial_ordering>> expected =
-            {
-                //0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15  16  17  18  19  20  21
-                {eq, eq, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, un, un}, //  0
-                {eq, eq, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, un, un}, //  1
-                {gt, gt, eq, lt, lt, lt, lt, lt, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  2
-                {gt, gt, gt, eq, gt, gt, gt, gt, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  3
-                {gt, gt, gt, lt, eq, lt, gt, lt, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  4
-                {gt, gt, gt, lt, gt, eq, gt, lt, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  5
-                {gt, gt, gt, lt, lt, lt, eq, lt, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  6
-                {gt, gt, gt, lt, gt, gt, gt, eq, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  7
-                {gt, gt, un, un, un, un, un, un, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  8
-                {gt, gt, un, un, un, un, un, un, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  9
-                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, eq, gt, gt, gt, gt, gt, gt, gt, lt, lt, un, un}, // 10
-                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, lt, eq, gt, gt, gt, gt, gt, gt, lt, lt, un, un}, // 11
-                {gt, gt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, eq, gt, lt, lt, lt, lt, lt, lt, un, un}, // 12
-                {gt, gt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, eq, lt, lt, lt, lt, lt, lt, un, un}, // 13
-                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, lt, lt, gt, gt, eq, lt, gt, gt, lt, lt, un, un}, // 14
-                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, lt, lt, gt, gt, gt, eq, gt, gt, lt, lt, un, un}, // 15
-                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, lt, lt, gt, gt, lt, lt, eq, gt, lt, lt, un, un}, // 16
-                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, lt, lt, gt, gt, lt, lt, lt, eq, lt, lt, un, un}, // 17
-                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, eq, lt, un, un}, // 18
-                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, eq, un, un}, // 19
-                {un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un}, // 20
-                {un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un}, // 21
-            };
-
-            // check expected partial_ordering against expected booleans
-            REQUIRE(expected.size() == expected_eq.size());
-            REQUIRE(expected.size() == expected_lt.size());
-            for (size_t i = 0; i < expected.size(); ++i)
-            {
-                REQUIRE(expected[i].size() == expected_eq[i].size());
-                REQUIRE(expected[i].size() == expected_lt[i].size());
-                for (size_t j = 0; j < expected[i].size(); ++j)
-                {
-                    CAPTURE(i)
-                    CAPTURE(j)
-                    CHECK(std::is_eq(expected[i][j]) == expected_eq[i][j]);
-                    CHECK(std::is_lt(expected[i][j]) == expected_lt[i][j]);
-                    if (std::is_gt(expected[i][j]))
-                    {
-                        CHECK((!expected_eq[i][j] && !expected_lt[i][j]));
-                    }
-                }
-            }
-
-            // check that two values compare according to their expected ordering
-            REQUIRE(expected.size() == j_values.size());
-            for (size_t i = 0; i < j_values.size(); ++i)
-            {
-                REQUIRE(expected[i].size() == j_values.size());
-                for (size_t j = 0; j < j_values.size(); ++j)
-                {
-                    CAPTURE(i)
-                    CAPTURE(j)
-                    CHECK((j_values[i] <=> j_values[j]) == expected[i][j]); // *NOPAD*
-                }
-            }
-        }
-    }
-
-}
-
-TEST_CASE("regression #3868 - heterogeneous comparisons compile under C++20 (P2468R2)")
-{
-    // Issue #3868: operator!= was preventing compiler from synthesizing reversed
-    // operator== candidates under C++20's P2468R2 rewritten candidate rules.
-    // Verify that heterogeneous comparisons now work.
-
-    SECTION("string vs json")
-    {
-        std::string s = "string";
-        json j = "string";
-        CHECK(s == j);
-        CHECK(j == s);
-        CHECK_FALSE(s != j);
-        CHECK_FALSE(j != s);
-    }
-
-    SECTION("other heterogeneous types")
-    {
-        int i = 42;
-        json j = 42;
-        CHECK(i == j);
-        CHECK(j == i);
-        CHECK_FALSE(i != j);
-        CHECK_FALSE(j != i);
-    }
-}
-
-#if JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON
-TEST_CASE("regression #5665 - scalar <= discarded and scalar >= discarded in C++20 legacy mode")
-{
-    // Issue #5665: with a scalar on the left-hand side, <= and >= only had the
-    // candidate rewritten from operator<=>, which does not emulate the legacy
-    // discarded-value behavior. Check that scalar-on-the-left now matches the
-    // other three operand orders.
-    const json discarded(json::value_t::discarded);
-    const json one = 1;
-
-    CHECK(discarded <= 1);
-    CHECK(discarded >= 1);
-    CHECK(one <= discarded);
-    CHECK(one >= discarded);
-    CHECK(1 <= discarded);
-    CHECK(1 >= discarded);
-    CHECK(1.5 <= discarded);
-    CHECK(1.5 >= discarded);
-}
-
-#endif
-
-TEST_CASE("containers are compared element by element (C++20)")
-{
-    // Containers nested deeper than a bound are compared without the call
-    // stack, by code of their own; every relation is checked both at the top
-    // level and below that bound.
-    const auto deep = [](const json & j, const std::size_t depth)
-    {
-        json result = j;
-        for (std::size_t i = 0; i < depth; ++i)
-        {
-            result = json::array({std::move(result)});
-        }
-        return result;
-    };
-
-    for (const std::size_t depth : std::vector<std::size_t> {0, 200})
-    {
-        CAPTURE(depth)
-
-        // objects with different keys
-        {
-            const json a = deep({{"a", 1}}, depth);
-            const json b = deep({{"b", 1}}, depth);
-            CHECK((a <=> b) == std::partial_ordering::less); // *NOPAD*
-            CHECK((b <=> a) == std::partial_ordering::greater); // *NOPAD*
-            CHECK((a <=> a) == std::partial_ordering::equivalent); // *NOPAD*
-        }
-
-        // a container that is a prefix of the other one
-        {
-            // the one that runs out of elements first is the smaller one
-            const json shorter = deep({1}, depth);
-            const json longer = deep({1, 2}, depth);
-
-            const json smaller_object = deep({{"a", 1}}, depth);
-            const json larger_object = deep({{"a", 1}, {"b", 2}}, depth);
-            CHECK((shorter <=> longer) == std::partial_ordering::less); // *NOPAD*
-            CHECK((longer <=> shorter) == std::partial_ordering::greater); // *NOPAD*
-        }
-
-        // elements that cannot be ordered
-        {
-            const double nan = std::numeric_limits<double>::quiet_NaN();
-            const json lhs = deep({nan, 1}, depth);
-            const json rhs = deep({nan, 2}, depth);
-            // operator<=> stops there, as std::lexicographical_compare_three_way
-            // does, and operator< is derived from it
-            CHECK((lhs <=> rhs) == std::partial_ordering::unordered); // *NOPAD*
-            CHECK_FALSE(lhs < rhs);
-        }
-    }
-}
-
-TEST_CASE("operator<=> of binary values with a different subtype does not depend on nesting depth")
-{
-    // #5654: std::vector<std::uint8_t>::operator<=>, which the binary type's
-    // own operator<=> uses, ignores the subtype that operator== checks. So a
-    // pair of binary values with the same bytes but a different subtype is
-    // unequal, yet <=>-equivalent - the same inconsistency between == and <=>
-    // that a NaN has. Within the nesting bound, an array compares itself
-    // with std::vector's own operator<=>, which treats an equivalent pair as
-    // undecided and lets the next element decide, same as
-    // std::lexicographical_compare_three_way does. Past the bound,
-    // compare_iteratively<true>() takes over and must classify the pair the
-    // same way, or the result of operator<=> - and of <, which C++20 derives
-    // from it - depends on how deeply the values are nested.
-    const json a = json::array({json::binary({1}, 1), 1});
-    const json b = json::array({json::binary({1}, 2), 2});
-
-    // the root inconsistency: unequal, yet <=>-equivalent
-    CHECK_FALSE(a[0] == b[0]);
-    CHECK((a[0] <=> b[0]) == std::partial_ordering::equivalent); // *NOPAD*
-
-    const auto deep = [](const json & j, const std::size_t depth)
-    {
-        json result = j;
-        for (std::size_t i = 0; i < depth; ++i)
-        {
-            result = json::array({std::move(result)});
-        }
-        return result;
-    };
-
-    // 127 levels stay within nesting_depth_limit() (128); 128 and 200 do not,
-    // and must still agree with the levels that do
-    for (const std::size_t depth : std::vector<std::size_t> {0, 127, 128, 200})
-    {
-        CAPTURE(depth)
-        const json x = deep(a, depth);
-        const json y = deep(b, depth);
-        CHECK((x <=> y) == std::partial_ordering::less); // *NOPAD*
-        CHECK((y <=> x) == std::partial_ordering::greater); // *NOPAD*
-        CHECK(x < y);
-        CHECK(y > x);
-        CHECK_FALSE(y < x);
-    }
-}
-
-TEST_CASE("comparison of scalars (inline fast path): operator<=>")
-{
-    // the three-way part of "comparison of scalars (inline fast path)" in
-    // unit-comparison.cpp, which is built for C++11 only
-    const json::number_integer_t neg = -1;
-
-    SECTION("NaN")
-    {
-        const json nan = std::numeric_limits<json::number_float_t>::quiet_NaN();
-        const json one = 1.0;
-        CHECK((nan <=> nan) == std::partial_ordering::unordered); // *NOPAD*
-        CHECK((nan <=> one) == std::partial_ordering::unordered); // *NOPAD*
-        CHECK((one <=> nan) == std::partial_ordering::unordered); // *NOPAD*
-        CHECK((one <=> json(2.0)) == std::partial_ordering::less); // *NOPAD*
-        CHECK((json(2.0) <=> one) == std::partial_ordering::greater); // *NOPAD*
-        CHECK((one <=> one) == std::partial_ordering::equivalent); // *NOPAD*
-        CHECK((json(neg) <=> json(1u)) == std::partial_ordering::less); // *NOPAD*
-        CHECK((json(nullptr) <=> json(nullptr)) == std::partial_ordering::equivalent); // *NOPAD*
-        CHECK((json(true) <=> json(false)) == std::partial_ordering::greater); // *NOPAD*
-    }
-
-    SECTION("discarded")
-    {
-        const json d(json::value_t::discarded);
-        CHECK((d <=> d) == std::partial_ordering::unordered); // *NOPAD*
-        CHECK((d <=> json(1)) == std::partial_ordering::unordered); // *NOPAD*
-        CHECK((json(1) <=> d) == std::partial_ordering::unordered); // *NOPAD*
-    }
-}
-
-#endif // JSON_HAS_THREE_WAY_COMPARISON
-#endif
@@ -6,11 +6,12 @@
 // SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
 // SPDX-License-Identifier: MIT

-// cmake/test.cmake builds a unit test with C++ standards beyond C++11 only if the
-// source file mentions the corresponding version macro. To avoid rebuilding this
-// large file for every standard, tests that depend on the standard version (e.g.,
-// those using JSON_HAS_FILESYSTEM, JSON_HAS_RANGES, or JSON_HAS_THREE_WAY_COMPARISON)
-// go into a separate file unit-comparison-cpp<NN>.cpp. This file stays C++11-only.
+// cmake/test.cmake selects the C++ standard versions with which to build a
+// unit test based on the presence of JSON_HAS_CPP_<VERSION> macros.
+// When using macros that are only defined for particular versions of the standard
+// (e.g., JSON_HAS_FILESYSTEM for C++17 and up), please mention the corresponding
+// version macro in a comment close by, like this:
+// JSON_HAS_CPP_<VERSION> (do not remove; see note at top of file)

 #include "doctest_compatibility.h"

@@ -28,6 +29,37 @@
 #include <nlohmann/json.hpp>
 using nlohmann::json;

+#if JSON_HAS_THREE_WAY_COMPARISON
+// this can be replaced with the doctest stl extension header in version 2.5
+namespace doctest
+{
+template<> struct StringMaker<std::partial_ordering>
+{
+    static String convert(const std::partial_ordering& order)
+    {
+        if (order == std::partial_ordering::less)
+        {
+            return "std::partial_ordering::less";
+        }
+        if (order == std::partial_ordering::equivalent)
+        {
+            return "std::partial_ordering::equivalent";
+        }
+        if (order == std::partial_ordering::greater)
+        {
+            return "std::partial_ordering::greater";
+        }
+        if (order == std::partial_ordering::unordered)
+        {
+            return "std::partial_ordering::unordered";
+        }
+        return "{?}";
+    }
+};
+} // namespace doctest
+
+#endif
+
 namespace
 {
 // helper function to check std::less<json::value_t>
@@ -44,6 +76,16 @@ TEST_CASE("lexicographical comparison operators")
    constexpr auto f_ = false;
    constexpr auto _t = true;
    constexpr auto nan = std::numeric_limits<json::number_float_t>::quiet_NaN();
+#if JSON_HAS_THREE_WAY_COMPARISON
+    constexpr auto lt = std::partial_ordering::less;
+    constexpr auto gt = std::partial_ordering::greater;
+    constexpr auto eq = std::partial_ordering::equivalent;
+    constexpr auto un = std::partial_ordering::unordered;
+#endif
+
+#if JSON_HAS_THREE_WAY_COMPARISON
+    INFO("using 3-way comparison");
+#endif

 #if JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON
    INFO("using legacy comparison");
@@ -94,13 +136,62 @@ TEST_CASE("lexicographical comparison operators")
                    CAPTURE(i)
                    CAPTURE(j)
                    // check precomputed values
-#if !JSON_HAS_THREE_WAY_COMPARISON
+#if JSON_HAS_THREE_WAY_COMPARISON
+                    // JSON_HAS_CPP_20 (do not remove; see note at top of file)
+                    CHECK((j_types[i] < j_types[j]) == expected_lt[i][j]);
+#else
                    CHECK(operator<(j_types[i], j_types[j]) == expected_lt[i][j]);
 #endif
                    CHECK(f(j_types[i], j_types[j]) == expected_lt[i][j]);
                }
            }
        }
+#if JSON_HAS_THREE_WAY_COMPARISON
+        // JSON_HAS_CPP_20 (do not remove; see note at top of file)
+        SECTION("comparison: 3-way")
+        {
+            std::vector<std::vector<std::partial_ordering>> expected =
+            {
+                //0   1   2   3   4   5   6   7   8   9
+                {eq, lt, lt, lt, lt, lt, lt, lt, lt, un}, //  0
+                {gt, eq, lt, lt, lt, lt, lt, lt, lt, un}, //  1
+                {gt, gt, eq, eq, eq, lt, lt, lt, lt, un}, //  2
+                {gt, gt, eq, eq, eq, lt, lt, lt, lt, un}, //  3
+                {gt, gt, eq, eq, eq, lt, lt, lt, lt, un}, //  4
+                {gt, gt, gt, gt, gt, eq, lt, lt, lt, un}, //  5
+                {gt, gt, gt, gt, gt, gt, eq, lt, lt, un}, //  6
+                {gt, gt, gt, gt, gt, gt, gt, eq, lt, un}, //  7
+                {gt, gt, gt, gt, gt, gt, gt, gt, eq, un}, //  8
+                {un, un, un, un, un, un, un, un, un, un}, //  9
+            };
+
+            // check expected partial_ordering against expected boolean
+            REQUIRE(expected.size() == expected_lt.size());
+            for (size_t i = 0; i < expected.size(); ++i)
+            {
+                REQUIRE(expected[i].size() == expected_lt[i].size());
+                for (size_t j = 0; j < expected[i].size(); ++j)
+                {
+                    CAPTURE(i)
+                    CAPTURE(j)
+                    CHECK(std::is_lt(expected[i][j]) == expected_lt[i][j]);
+                }
+            }
+
+            // check 3-way comparison against expected partial_ordering
+            REQUIRE(expected.size() == j_types.size());
+            for (size_t i = 0; i < j_types.size(); ++i)
+            {
+                REQUIRE(expected[i].size() == j_types.size());
+                for (size_t j = 0; j < j_types.size(); ++j)
+                {
+                    CAPTURE(i)
+                    CAPTURE(j)
+                    CHECK((j_types[i] <=> j_types[j]) == expected[i][j]); // *NOPAD*
+                }
+            }
+        }
+#endif
    }

    SECTION("values")
@@ -229,6 +320,18 @@ TEST_CASE("lexicographical comparison operators")
            CHECK_FALSE(above_int64_max <= max_int64);
            CHECK(above_int64_max > max_int64);
            CHECK(above_int64_max >= max_int64);
+
+#if JSON_HAS_THREE_WAY_COMPARISON
+            // JSON_HAS_CPP_20 (do not remove; see note at top of file)
+            CHECK((negative_one <=> above_int64_max) == std::partial_ordering::less); // *NOPAD*
+            CHECK((above_int64_max <=> negative_one) == std::partial_ordering::greater); // *NOPAD*
+            CHECK((negative_one <=> max_uint64) == std::partial_ordering::less); // *NOPAD*
+            CHECK((max_uint64 <=> negative_one) == std::partial_ordering::greater); // *NOPAD*
+            CHECK((one <=> above_int64_max) == std::partial_ordering::less); // *NOPAD*
+            CHECK((above_int64_max <=> one) == std::partial_ordering::greater); // *NOPAD*
+            CHECK((max_int64 <=> above_int64_max) == std::partial_ordering::less); // *NOPAD*
+            CHECK((above_int64_max <=> max_int64) == std::partial_ordering::greater); // *NOPAD*
+#endif
        }

        SECTION("integer/float mixed comparison is exact")
@@ -279,6 +382,16 @@ TEST_CASE("lexicographical comparison operators")
            CHECK_FALSE(json(1) < json(nan));
            CHECK_FALSE(json(nan) < json(1));
            CHECK_FALSE(json(1u) == json(nan));
+
+#if JSON_HAS_THREE_WAY_COMPARISON
+            // JSON_HAS_CPP_20 (do not remove; see note at top of file)
+            CHECK((max_int64 <=> two_63) == std::partial_ordering::less); // *NOPAD*
+            CHECK((two_63 <=> max_int64) == std::partial_ordering::greater); // *NOPAD*
+            CHECK((below_two_63 <=> max_int64) == std::partial_ordering::less); // *NOPAD*
+            CHECK((max_uint64 <=> two_64) == std::partial_ordering::less); // *NOPAD*
+            CHECK((json(1) <=> json(1.0)) == std::partial_ordering::equivalent); // *NOPAD*
+            CHECK((json(1) <=> json(nan)) == std::partial_ordering::unordered); // *NOPAD*
+#endif
        }

        SECTION("compares unordered")
@@ -505,6 +618,72 @@ TEST_CASE("lexicographical comparison operators")
                }
            }
        }
+
+#if JSON_HAS_THREE_WAY_COMPARISON
+        // JSON_HAS_CPP_20 (do not remove; see note at top of file)
+        SECTION("comparison: 3-way")
+        {
+            std::vector<std::vector<std::partial_ordering>> expected =
+            {
+                //0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15  16  17  18  19  20  21
+                {eq, eq, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, un, un}, //  0
+                {eq, eq, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, un, un}, //  1
+                {gt, gt, eq, lt, lt, lt, lt, lt, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  2
+                {gt, gt, gt, eq, gt, gt, gt, gt, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  3
+                {gt, gt, gt, lt, eq, lt, gt, lt, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  4
+                {gt, gt, gt, lt, gt, eq, gt, lt, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  5
+                {gt, gt, gt, lt, lt, lt, eq, lt, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  6
+                {gt, gt, gt, lt, gt, gt, gt, eq, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  7
+                {gt, gt, un, un, un, un, un, un, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  8
+                {gt, gt, un, un, un, un, un, un, un, un, lt, lt, gt, gt, lt, lt, lt, lt, lt, lt, un, un}, //  9
+                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, eq, gt, gt, gt, gt, gt, gt, gt, lt, lt, un, un}, // 10
+                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, lt, eq, gt, gt, gt, gt, gt, gt, lt, lt, un, un}, // 11
+                {gt, gt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, eq, gt, lt, lt, lt, lt, lt, lt, un, un}, // 12
+                {gt, gt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, lt, eq, lt, lt, lt, lt, lt, lt, un, un}, // 13
+                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, lt, lt, gt, gt, eq, lt, gt, gt, lt, lt, un, un}, // 14
+                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, lt, lt, gt, gt, gt, eq, gt, gt, lt, lt, un, un}, // 15
+                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, lt, lt, gt, gt, lt, lt, eq, gt, lt, lt, un, un}, // 16
+                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, lt, lt, gt, gt, lt, lt, lt, eq, lt, lt, un, un}, // 17
+                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, eq, lt, un, un}, // 18
+                {gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, gt, eq, un, un}, // 19
+                {un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un}, // 20
+                {un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un, un}, // 21
+            };
+
+            // check expected partial_ordering against expected booleans
+            REQUIRE(expected.size() == expected_eq.size());
+            REQUIRE(expected.size() == expected_lt.size());
+            for (size_t i = 0; i < expected.size(); ++i)
+            {
+                REQUIRE(expected[i].size() == expected_eq[i].size());
+                REQUIRE(expected[i].size() == expected_lt[i].size());
+                for (size_t j = 0; j < expected[i].size(); ++j)
+                {
+                    CAPTURE(i)
+                    CAPTURE(j)
+                    CHECK(std::is_eq(expected[i][j]) == expected_eq[i][j]);
+                    CHECK(std::is_lt(expected[i][j]) == expected_lt[i][j]);
+                    if (std::is_gt(expected[i][j]))
+                    {
+                        CHECK((!expected_eq[i][j] && !expected_lt[i][j]));
+                    }
+                }
+            }
+
+            // check that two values compare according to their expected ordering
+            REQUIRE(expected.size() == j_values.size());
+            for (size_t i = 0; i < j_values.size(); ++i)
+            {
+                REQUIRE(expected[i].size() == j_values.size());
+                for (size_t j = 0; j < j_values.size(); ++j)
+                {
+                    CAPTURE(i)
+                    CAPTURE(j)
+                    CHECK((j_values[i] <=> j_values[j]) == expected[i][j]); // *NOPAD*
+                }
+            }
+        }
+#endif
    }

 #if JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON
@@ -543,7 +722,60 @@ TEST_CASE("lexicographical comparison operators")
 #endif
 }

-namespace unit_comparison_detail
+#if JSON_HAS_THREE_WAY_COMPARISON
+// JSON_HAS_CPP_20 (do not remove; see note at top of file)
+
+TEST_CASE("regression #3868 - heterogeneous comparisons compile under C++20 (P2468R2)")
+{
+    // Issue #3868: operator!= was preventing compiler from synthesizing reversed
+    // operator== candidates under C++20's P2468R2 rewritten candidate rules.
+    // Verify that heterogeneous comparisons now work.
+
+    SECTION("string vs json")
+    {
+        std::string s = "string";
+        json j = "string";
+        CHECK(s == j);
+        CHECK(j == s);
+        CHECK_FALSE(s != j);
+        CHECK_FALSE(j != s);
+    }
+
+    SECTION("other heterogeneous types")
+    {
+        int i = 42;
+        json j = 42;
+        CHECK(i == j);
+        CHECK(j == i);
+        CHECK_FALSE(i != j);
+        CHECK_FALSE(j != i);
+    }
+}
+
+#if JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON
+TEST_CASE("regression #5665 - scalar <= discarded and scalar >= discarded in C++20 legacy mode")
+{
+    // Issue #5665: with a scalar on the left-hand side, <= and >= only had the
+    // candidate rewritten from operator<=>, which does not emulate the legacy
+    // discarded-value behavior. Check that scalar-on-the-left now matches the
+    // other three operand orders.
+    const json discarded(json::value_t::discarded);
+    const json one = 1;
+
+    CHECK(discarded <= 1);
+    CHECK(discarded >= 1);
+    CHECK(one <= discarded);
+    CHECK(one >= discarded);
+    CHECK(1 <= discarded);
+    CHECK(1 >= discarded);
+    CHECK(1.5 <= discarded);
+    CHECK(1.5 >= discarded);
+}
+#endif
+
+#endif
+
+namespace
 {
 // orders keys ascending or descending, as chosen when a map is created
 template<class Key>
@@ -595,6 +827,29 @@ struct unordered_object_t : std::map<Key, Value, directed_less<Key>, Allocator>
 };
 using unordered_json = nlohmann::json::with_object_t<unordered_object_t>;

+// the entries "0" to "9", enumerated in ascending or in descending order
+unordered_json make_unordered_object(const bool descending)
+{
+    unordered_json j = unordered_json::object_t(directed_less<std::string>(descending));
+    for (int i = 0; i < 10; ++i)
+    {
+        j[std::to_string(i)] = i;
+    }
+    return j;
+}
+
+template<typename Json>
+Json nest(Json j, const std::size_t depth)
+{
+    for (std::size_t i = 0; i < depth; ++i)
+    {
+        Json outer = Json::object();
+        outer["x"] = std::move(j);
+        j = std::move(outer);
+    }
+    return j;
+}
+
 // a std::map comparator with state: case-insensitive, unless constructed
 // case-sensitive. Used to check that copying an object copies the original's
 // comparator rather than default-constructing a new one (see #5649).
@@ -623,6 +878,18 @@ template<class Key, class Value, class /*Compare*/, class Allocator>
 using key_case_map = std::map<Key, Value, key_case_less, Allocator>;
 using key_case_json = nlohmann::json::with_object_t<key_case_map>;

+// the innermost value of a chain of single-element arrays
+template<typename Json>
+const Json& innermost(const Json& j)
+{
+    const Json* p = &j;
+    while (p->is_array())
+    {
+        p = &(*p)[0];
+    }
+    return *p;
+}
+
 // orders keys case-insensitively, so "key" and "KEY" compare equivalent
 // (neither less than the other) although they are not equal
 struct case_insensitive_less
@@ -640,58 +907,7 @@ struct case_insensitive_less
 template<class Key, class Value, class /*Compare*/, class Allocator>
 using case_insensitive_map = std::map<Key, Value, case_insensitive_less, Allocator>;
 using ci_json = nlohmann::json::with_object_t<case_insensitive_map>;
-
-// the types above keep external linkage: a basic_json specialized with a type
-// of an anonymous namespace has internal linkage, which GCC reports in a file
-// #include-d into a batch (-Wsubobject-linkage); the functions need none
-namespace
-{
-// the entries "0" to "9", enumerated in ascending or in descending order
-unordered_json make_unordered_object(const bool descending)
-{
-    unordered_json j = unordered_json::object_t(directed_less<std::string>(descending));
-    for (int i = 0; i < 10; ++i)
-    {
-        j[std::to_string(i)] = i;
-    }
-    return j;
-}
-
-template<typename Json>
-Json nest(Json j, const std::size_t depth)
-{
-    for (std::size_t i = 0; i < depth; ++i)
-    {
-        Json outer = Json::object();
-        outer["x"] = std::move(j);
-        j = std::move(outer);
-    }
-    return j;
-}
-
-// the innermost value of a chain of single-element arrays
-template<typename Json>
-const Json& innermost(const Json& j)
-{
-    const Json* p = &j;
-    while (p->is_array())
-    {
-        p = &(*p)[0];
-    }
-    return *p;
-}
 } // namespace
-} // namespace unit_comparison_detail
-
-// using-declarations rather than a using-directive, as this file may be
-// #include-d into a batch with other test files (JSON_TestUnityBuild)
-using unit_comparison_detail::ci_json;
-using unit_comparison_detail::innermost;
-using unit_comparison_detail::key_case_json;
-using unit_comparison_detail::key_case_less;
-using unit_comparison_detail::make_unordered_object;
-using unit_comparison_detail::nest;
-using unit_comparison_detail::unordered_json;

 TEST_CASE("equality of objects whose entries have no fixed order")
 {
@@ -834,6 +1050,12 @@ TEST_CASE("containers are compared element by element")
            CHECK(a < b);
            CHECK(b > a);
            CHECK_FALSE(b < a);
+#if JSON_HAS_THREE_WAY_COMPARISON
+            // JSON_HAS_CPP_20 (do not remove; see note at top of file)
+            CHECK((a <=> b) == std::partial_ordering::less); // *NOPAD*
+            CHECK((b <=> a) == std::partial_ordering::greater); // *NOPAD*
+            CHECK((a <=> a) == std::partial_ordering::equivalent); // *NOPAD*
+#endif
        }

        // a container that is a prefix of the other one
@@ -851,6 +1073,11 @@ TEST_CASE("containers are compared element by element")
            CHECK(smaller_object < larger_object);
            CHECK(larger_object > smaller_object);
            CHECK_FALSE(smaller_object == larger_object);
+#if JSON_HAS_THREE_WAY_COMPARISON
+            // JSON_HAS_CPP_20 (do not remove; see note at top of file)
+            CHECK((shorter <=> longer) == std::partial_ordering::less); // *NOPAD*
+            CHECK((longer <=> shorter) == std::partial_ordering::greater); // *NOPAD*
+#endif
        }

        // elements that cannot be ordered
@@ -861,7 +1088,13 @@ TEST_CASE("containers are compared element by element")

            CHECK_FALSE(lhs == lhs);
            CHECK_FALSE(rhs < lhs);
-#if !JSON_HAS_THREE_WAY_COMPARISON
+#if JSON_HAS_THREE_WAY_COMPARISON
+            // JSON_HAS_CPP_20 (do not remove; see note at top of file)
+            // operator<=> stops there, as std::lexicographical_compare_three_way
+            // does, and operator< is derived from it
+            CHECK((lhs <=> rhs) == std::partial_ordering::unordered); // *NOPAD*
+            CHECK_FALSE(lhs < rhs);
+#else
            // operator< skips a pair of elements that cannot be ordered, as
            // std::lexicographical_compare does, and the next pair decides
            CHECK(lhs < rhs);
@@ -870,6 +1103,54 @@ TEST_CASE("containers are compared element by element")
    }
 }

+#if JSON_HAS_THREE_WAY_COMPARISON
+// JSON_HAS_CPP_20 (do not remove; see note at top of file)
+TEST_CASE("operator<=> of binary values with a different subtype does not depend on nesting depth")
+{
+    // #5654: std::vector<std::uint8_t>::operator<=>, which the binary type's
+    // own operator<=> uses, ignores the subtype that operator== checks. So a
+    // pair of binary values with the same bytes but a different subtype is
+    // unequal, yet <=>-equivalent - the same inconsistency between == and <=>
+    // that a NaN has. Within the nesting bound, an array compares itself
+    // with std::vector's own operator<=>, which treats an equivalent pair as
+    // undecided and lets the next element decide, same as
+    // std::lexicographical_compare_three_way does. Past the bound,
+    // compare_iteratively<true>() takes over and must classify the pair the
+    // same way, or the result of operator<=> - and of <, which C++20 derives
+    // from it - depends on how deeply the values are nested.
+    const json a = json::array({json::binary({1}, 1), 1});
+    const json b = json::array({json::binary({1}, 2), 2});
+
+    // the root inconsistency: unequal, yet <=>-equivalent
+    CHECK_FALSE(a[0] == b[0]);
+    CHECK((a[0] <=> b[0]) == std::partial_ordering::equivalent); // *NOPAD*
+
+    const auto deep = [](const json & j, const std::size_t depth)
+    {
+        json result = j;
+        for (std::size_t i = 0; i < depth; ++i)
+        {
+            result = json::array({std::move(result)});
+        }
+        return result;
+    };
+
+    // 127 levels stay within nesting_depth_limit() (128); 128 and 200 do not,
+    // and must still agree with the levels that do
+    for (const std::size_t depth : std::vector<std::size_t> {0, 127, 128, 200})
+    {
+        CAPTURE(depth)
+        const json x = deep(a, depth);
+        const json y = deep(b, depth);
+        CHECK((x <=> y) == std::partial_ordering::less); // *NOPAD*
+        CHECK((y <=> x) == std::partial_ordering::greater); // *NOPAD*
+        CHECK(x < y);
+        CHECK(y > x);
+        CHECK_FALSE(y < x);
+    }
+}
+#endif
+
 TEST_CASE("comparison of scalars (inline fast path)")
 {
    const json::number_integer_t neg = -1;
@@ -968,6 +1249,17 @@ TEST_CASE("comparison of scalars (inline fast path)")
        CHECK_FALSE(nan < json(1u));
        CHECK_FALSE(json(1u) < nan);

+#if JSON_HAS_THREE_WAY_COMPARISON
+        CHECK((nan <=> nan) == std::partial_ordering::unordered); // *NOPAD*
+        CHECK((nan <=> one) == std::partial_ordering::unordered); // *NOPAD*
+        CHECK((one <=> nan) == std::partial_ordering::unordered); // *NOPAD*
+        CHECK((one <=> json(2.0)) == std::partial_ordering::less); // *NOPAD*
+        CHECK((json(2.0) <=> one) == std::partial_ordering::greater); // *NOPAD*
+        CHECK((one <=> one) == std::partial_ordering::equivalent); // *NOPAD*
+        CHECK((json(neg) <=> json(1u)) == std::partial_ordering::less); // *NOPAD*
+        CHECK((json(nullptr) <=> json(nullptr)) == std::partial_ordering::equivalent); // *NOPAD*
+        CHECK((json(true) <=> json(false)) == std::partial_ordering::greater); // *NOPAD*
+#endif
    }

    SECTION("discarded")
@@ -983,6 +1275,11 @@ TEST_CASE("comparison of scalars (inline fast path)")
        CHECK_FALSE(d == json(nullptr));
        CHECK_FALSE(json(nullptr) == d);

+#if JSON_HAS_THREE_WAY_COMPARISON
+        CHECK((d <=> d) == std::partial_ordering::unordered); // *NOPAD*
+        CHECK((d <=> json(1)) == std::partial_ordering::unordered); // *NOPAD*
+        CHECK((json(1) <=> d) == std::partial_ordering::unordered); // *NOPAD*
+#endif
    }

    SECTION("scalar overloads")
@@ -1,95 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-// This file contains the C++17-only part of unit-conversions1.cpp (conversions to and from
-// std::string_view). It is kept in a separate translation unit so the (much larger) unit-
-// conversions1.cpp is built for C++11 only and not rebuilt for every C++ standard.
-
-#include "doctest_compatibility.h"
-
-#include <nlohmann/json.hpp>
-using nlohmann::json;
-
-// workaround for MSVC, which does not set __cplusplus to the language version (#464)
-#if (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464
-    #define JSON_HAS_CPP_17
-#endif
-
-#ifdef JSON_HAS_CPP_17
-#include <string>
-#include <string_view>
-
-#if __has_include(<optional>)
-    #include <optional>
-#elif __has_include(<experimental/optional>)
-    #include <experimental/optional>
-#endif
-
-TEST_CASE("value conversion (C++17)")
-{
-    SECTION("get a string (explicit)")
-    {
-        const json::string_t s_reference{"Hello world"};
-        json j(s_reference);
-
-        SECTION("std::string_view")
-        {
-            std::string_view const s = j.get<std::string_view>();
-            CHECK(json(s) == j);
-        }
-
-        SECTION("exception in case of a non-string type using string_view")
-        {
-            CHECK_THROWS_WITH_AS(json(json::value_t::null).get<std::string_view>(),
-                                 "[json.exception.type_error.302] type must be string, but is null", json::type_error&);
-            CHECK_THROWS_WITH_AS(json(json::value_t::object).get<std::string_view>(),
-                                 "[json.exception.type_error.302] type must be string, but is object", json::type_error&);
-            CHECK_THROWS_WITH_AS(json(json::value_t::array).get<std::string_view>(),
-                                 "[json.exception.type_error.302] type must be string, but is array", json::type_error&);
-            CHECK_THROWS_WITH_AS(json(json::value_t::boolean).get<std::string_view>(),
-                                 "[json.exception.type_error.302] type must be string, but is boolean", json::type_error&);
-            CHECK_THROWS_WITH_AS(json(json::value_t::number_integer).get<std::string_view>(),
-                                 "[json.exception.type_error.302] type must be string, but is number", json::type_error&);
-            CHECK_THROWS_WITH_AS(json(json::value_t::number_unsigned).get<std::string_view>(),
-                                 "[json.exception.type_error.302] type must be string, but is number", json::type_error&);
-            CHECK_THROWS_WITH_AS(json(json::value_t::number_float).get<std::string_view>(),
-                                 "[json.exception.type_error.302] type must be string, but is number", json::type_error&);
-        }
-    }
-
-    SECTION("get a string (explicit, get_to)")
-    {
-        const json::string_t s_reference{"Hello world"};
-        json j(s_reference);
-
-        SECTION("std::string_view")
-        {
-            std::string const s = "previous value";
-            std::string_view sv = s;
-            j.get_to(sv);
-            CHECK(json(sv) == j);
-        }
-    }
-
-#if JSON_USE_IMPLICIT_CONVERSIONS
-    SECTION("get a string (implicit)")
-    {
-        const json::string_t s_reference{"Hello world"};
-        json j(s_reference);
-
-        SECTION("std::string_view")
-        {
-            std::string_view const s = j.get<std::string_view>();
-            CHECK(json(s) == j);
-        }
-    }
-#endif
-
-}
-
-#endif
@@ -6,11 +6,12 @@
 // SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
 // SPDX-License-Identifier: MIT

-// cmake/test.cmake builds a unit test with C++ standards beyond C++11 only if the
-// source file mentions the corresponding version macro. To avoid rebuilding this
-// large file for every standard, tests that depend on the standard version (e.g.,
-// those using JSON_HAS_FILESYSTEM, JSON_HAS_RANGES, or JSON_HAS_THREE_WAY_COMPARISON)
-// go into a separate file unit-conversions1-cpp<NN>.cpp. This file stays C++11-only.
+// cmake/test.cmake selects the C++ standard versions with which to build a
+// unit test based on the presence of JSON_HAS_CPP_<VERSION> macros.
+// When using macros that are only defined for particular versions of the standard
+// (e.g., JSON_HAS_FILESYSTEM for C++17 and up), please mention the corresponding
+// version macro in a comment close by, like this:
+// JSON_HAS_CPP_<VERSION> (do not remove; see note at top of file)

 #include "doctest_compatibility.h"

@@ -30,6 +31,25 @@ using nlohmann::json;
 DOCTEST_CLANG_SUPPRESS_WARNING_PUSH
 DOCTEST_CLANG_SUPPRESS_WARNING("-Wexit-time-destructors")

+#if (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464
+    #define JSON_HAS_CPP_17
+    #define JSON_HAS_CPP_14
+#elif (defined(__cplusplus) && __cplusplus >= 201402L) || (defined(_HAS_CXX14) && _HAS_CXX14 == 1)
+    #define JSON_HAS_CPP_14
+#endif
+
+#ifdef JSON_HAS_CPP_17
+    #if __has_include(<optional>)
+        #include <optional>
+    #elif __has_include(<experimental/optional>)
+        #include <experimental/optional>
+    #endif
+#endif
+
+#if defined(JSON_HAS_CPP_17)
+    #include <string_view>
+#endif
+
 TEST_CASE("value conversion")
 {
    SECTION("get an object (explicit)")
@@ -499,6 +519,13 @@ TEST_CASE("value conversion")
            const std::string s = j.get<std::string>();
            CHECK(json(s) == j);
        }
+#if defined(JSON_HAS_CPP_17)
+        SECTION("std::string_view")
+        {
+            std::string_view const s = j.get<std::string_view>();
+            CHECK(json(s) == j);
+        }
+#endif

        SECTION("exception in case of a non-string type")
        {
@@ -524,6 +551,26 @@ TEST_CASE("value conversion")
                json(json::value_t::number_float).get<json::string_t>(),
                "[json.exception.type_error.302] type must be string, but is number", json::type_error&);
        }
+
+#if defined(JSON_HAS_CPP_17)
+        SECTION("exception in case of a non-string type using string_view")
+        {
+            CHECK_THROWS_WITH_AS(json(json::value_t::null).get<std::string_view>(),
+                                 "[json.exception.type_error.302] type must be string, but is null", json::type_error&);
+            CHECK_THROWS_WITH_AS(json(json::value_t::object).get<std::string_view>(),
+                                 "[json.exception.type_error.302] type must be string, but is object", json::type_error&);
+            CHECK_THROWS_WITH_AS(json(json::value_t::array).get<std::string_view>(),
+                                 "[json.exception.type_error.302] type must be string, but is array", json::type_error&);
+            CHECK_THROWS_WITH_AS(json(json::value_t::boolean).get<std::string_view>(),
+                                 "[json.exception.type_error.302] type must be string, but is boolean", json::type_error&);
+            CHECK_THROWS_WITH_AS(json(json::value_t::number_integer).get<std::string_view>(),
+                                 "[json.exception.type_error.302] type must be string, but is number", json::type_error&);
+            CHECK_THROWS_WITH_AS(json(json::value_t::number_unsigned).get<std::string_view>(),
+                                 "[json.exception.type_error.302] type must be string, but is number", json::type_error&);
+            CHECK_THROWS_WITH_AS(json(json::value_t::number_float).get<std::string_view>(),
+                                 "[json.exception.type_error.302] type must be string, but is number", json::type_error&);
+        }
+#endif
    }

    SECTION("get a string (explicit, get_to)")
@@ -544,6 +591,15 @@ TEST_CASE("value conversion")
            j.get_to(s);
            CHECK(json(s) == j);
        }
+#if defined(JSON_HAS_CPP_17)
+        SECTION("std::string_view")
+        {
+            std::string const s = "previous value";
+            std::string_view sv = s;
+            j.get_to(sv);
+            CHECK(json(sv) == j);
+        }
+#endif
    }

    SECTION("get null (explicit)")
@@ -582,6 +638,14 @@ TEST_CASE("value conversion")
            CHECK(json(s) == j);
        }

+#if defined(JSON_HAS_CPP_17)
+        SECTION("std::string_view")
+        {
+            std::string_view const s = j.get<std::string_view>();
+            CHECK(json(s) == j);
+        }
+#endif
+
        SECTION("std::string")
        {
            const std::string s = j;
@@ -1192,4 +1256,11 @@ TEST_CASE("value conversion")
 #endif
 }

+#ifdef JSON_HAS_CPP_17
+    #undef JSON_HAS_CPP_17
+#endif
+
+#ifdef JSON_HAS_CPP_14
+    #undef JSON_HAS_CPP_14
+#endif
 DOCTEST_CLANG_SUPPRESS_WARNING_POP
@@ -1,225 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-// This file contains the C++17-only part of unit-conversions2.cpp (conversions of
-// std::filesystem::path, std::u8string and std::optional). It is kept in a separate
-// translation unit so the (much larger) unit-conversions2.cpp is built for C++11 only and
-// not rebuilt for every C++ standard.
-
-#include "doctest_compatibility.h"
-
-#include <nlohmann/json.hpp>
-using nlohmann::json;
-
-// workaround for MSVC, which does not set __cplusplus to the language version (#464)
-#if (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464
-    #define JSON_HAS_CPP_17
-#endif
-
-// NLOHMANN_JSON_SERIALIZE_ENUM uses a static std::pair
-DOCTEST_CLANG_SUPPRESS_WARNING_PUSH
-DOCTEST_CLANG_SUPPRESS_WARNING("-Wexit-time-destructors")
-
-#ifdef JSON_HAS_CPP_17
-#include <map>
-#include <stdexcept>
-#include <string>
-#include <string_view>
-#include <type_traits>
-#include <vector>
-
-#if __has_include(<optional>)
-    #include <optional>
-#elif __has_include(<experimental/optional>)
-    #include <experimental/optional>
-#endif
-
-#if JSON_HAS_FILESYSTEM || JSON_HAS_EXPERIMENTAL_FILESYSTEM
-TEST_CASE("std::filesystem::path")
-{
-    SECTION("ascii")
-    {
-        json const j_string = "Path";
-        auto p = j_string.template get<nlohmann::detail::std_fs::path>();
-        json const j_path = p;
-
-        CHECK(j_path.template get<std::string>() ==
-              j_string.template get<std::string>());
-    }
-
-    SECTION("utf-8")
-    {
-        json const j_string = "P\xc4\x9b\xc5\xa1ina";
-        auto p = j_string.template get<nlohmann::detail::std_fs::path>();
-        json const j_path = p;
-
-        CHECK(j_path.template get<std::string>() ==
-              j_string.template get<std::string>());
-    }
-}
-
-#endif
-
-// the ADL to_json overload for std::u8string only exists under the same guard
-// as std::filesystem::path support (it is otherwise only reached indirectly,
-// via std::filesystem::path::u8string()) -- mirror both #if conditions from
-// include/nlohmann/detail/conversions/to_json.hpp exactly
-#if JSON_HAS_FILESYSTEM || JSON_HAS_EXPERIMENTAL_FILESYSTEM
-#if defined(__cpp_lib_char8_t)
-TEST_CASE("std::u8string")
-{
-    SECTION("ascii")
-    {
-        const std::u8string s = u8"Path";
-        json const j = s;
-
-        CHECK(j.template get<std::string>() == "Path");
-    }
-
-    SECTION("utf-8")
-    {
-        // use \u universal-character-names (rather than raw \x byte escapes
-        // or literal non-ASCII source bytes) to compose the multi-byte UTF-8
-        // encoding -- MSVC treats \x escapes used that way inside a u8
-        // literal as a nonstandard extension (warning C5321), which some of
-        // our CI configs promote to an error; \u is portable and produces
-        // the exact same encoded bytes without depending on the source
-        // file's encoding
-        const std::u8string s = u8"P\u011B\u0161ina";
-        json const j = s;
-
-        CHECK(j.template get<std::string>() == "P\xc4\x9b\xc5\xa1ina");
-    }
-}
-
-#endif
-#endif
-
-#if !defined(JSON_NOEXCEPTION)
-namespace
-{
-// a type whose to_json reports an error by throwing, used below to check that
-// converting a std::optional<T> to JSON propagates an exception thrown while
-// converting its contained value instead of calling std::terminate (#5642)
-struct throwing_to_json_type {};
-
-[[noreturn]] void to_json(json& /*unused*/, const throwing_to_json_type& /*unused*/)
-{
-    throw std::runtime_error("cannot serialize throwing_to_json_type");
-}
-}  // namespace
-#endif
-
-TEST_CASE("std::optional")
-{
-    SECTION("null")
-    {
-        const json j_null;
-        const std::optional<std::string> opt_null;
-
-        CHECK(json(opt_null) == j_null);
-        CHECK(j_null.get<std::optional<std::string>>() == std::nullopt);
-
-        // Constructing std::optional<T> directly from JSON null throws because
-        // std::optional's own converting constructor is chosen over basic_json's
-        // operator T(). This is a language-level limitation (std::optional<T> is
-        // constructible from T, and T is constructible from basic_json via the
-        // operator); there is no SFINAE path that distinguishes "call from inside
-        // std::optional's constructor" from "direct call". Use get<std::optional<T>>()
-        // or get_to() instead for correct null handling. See #4864 and #5246.
-        CHECK_THROWS_WITH_AS(std::optional<std::string>(j_null),
-                             "[json.exception.type_error.302] type must be string, but is null", json::type_error&);
-        CHECK_THROWS_WITH_AS(std::optional<int>(j_null),
-                             "[json.exception.type_error.302] type must be number, but is null", json::type_error&);
-
-        // Assignment goes through the same overload resolution as direct
-        // construction, so it throws for the same reason. This relies on
-        // basic_json's implicit conversion operator, so it only applies
-        // when JSON_USE_IMPLICIT_CONVERSIONS is enabled (the default).
-#if JSON_USE_IMPLICIT_CONVERSIONS
-        std::optional<std::string> opt_assign;
-        CHECK_THROWS_WITH_AS(opt_assign = j_null,
-                             "[json.exception.type_error.302] type must be string, but is null", json::type_error&);
-#endif
-
-        // get_to() is the correct way to obtain std::nullopt from a JSON null.
-        std::optional<std::string> opt_get_to = "placeholder";
-        j_null.get_to(opt_get_to);
-        CHECK(opt_get_to == std::nullopt);
-    }
-
-    SECTION("string")
-    {
-        json j_string = "string";
-        std::optional<std::string> opt_string = "string";
-
-        CHECK(json(opt_string) == j_string);
-        CHECK(std::optional<std::string>(j_string) == opt_string);
-        // false positive: Infer attributes the destruction of the temporaries above to opt_string
-        // @infer-ignore USE_AFTER_DELETE
-    }
-
-    SECTION("bool")
-    {
-        json j_bool = true;
-        std::optional<bool> opt_bool = true;
-
-        CHECK(json(opt_bool) == j_bool);
-        CHECK(std::optional<bool>(j_bool) == opt_bool);
-    }
-
-    SECTION("number")
-    {
-        json j_number = 1;
-        std::optional<int> opt_int = 1;
-
-        CHECK(json(opt_int) == j_number);
-        CHECK(j_number.get<std::optional<int>>() == opt_int);
-    }
-
-    SECTION("array")
-    {
-        json j_array = {1, 2, nullptr};
-        std::vector<std::optional<int>> opt_array = {{1, 2, std::nullopt}};
-
-        CHECK(json(opt_array) == j_array);
-        CHECK(j_array.get<std::vector<std::optional<int>>>() == opt_array);
-    }
-
-    SECTION("object")
-    {
-        json j_object = {{"one", 1}, {"two", 2}, {"zero", nullptr}};
-        std::map<std::string, std::optional<int>> opt_object {{"one", 1}, {"two", 2}, {"zero", std::nullopt}};
-
-        CHECK(json(opt_object) == j_object);
-        CHECK(std::map<std::string, std::optional<int>>(j_object) == opt_object);
-    }
-
-#if !defined(JSON_NOEXCEPTION)
-    SECTION("exception from contained value's to_json propagates (#5642)")
-    {
-        // to_json(BasicJsonType&, const std::optional<T>&) must not be
-        // noexcept: it calls T's to_json, which may throw (a user-defined
-        // to_json that reports an error, or std::bad_alloc for T =
-        // std::string/vector/json). Before the fix, this called
-        // std::terminate() instead of letting the exception propagate.
-        const std::optional<throwing_to_json_type> opt = throwing_to_json_type{};
-        CHECK_THROWS_WITH_AS(json(opt), "cannot serialize throwing_to_json_type", std::runtime_error&);
-
-        // the conversion is noexcept exactly when converting the contained value is
-        // (except with MSVC 2017, where it is never noexcept, see to_json.hpp)
-#if !defined(_MSC_VER) || defined(__clang__) || _MSC_VER >= 1920
-        static_assert(!std::is_nothrow_constructible<json, const std::optional<throwing_to_json_type>&>::value);
-        static_assert(std::is_nothrow_constructible<json, const std::optional<int>&>::value);
-#endif
-    }
-#endif
-}
-
-DOCTEST_CLANG_SUPPRESS_WARNING_POP
-#endif
@@ -6,11 +6,12 @@
 // SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
 // SPDX-License-Identifier: MIT

-// cmake/test.cmake builds a unit test with C++ standards beyond C++11 only if the
-// source file mentions the corresponding version macro. To avoid rebuilding this
-// large file for every standard, tests that depend on the standard version (e.g.,
-// those using JSON_HAS_FILESYSTEM, JSON_HAS_RANGES, or JSON_HAS_THREE_WAY_COMPARISON)
-// go into a separate file unit-conversions2-cpp<NN>.cpp. This file stays C++11-only.
+// cmake/test.cmake selects the C++ standard versions with which to build a
+// unit test based on the presence of JSON_HAS_CPP_<VERSION> macros.
+// When using macros that are only defined for particular versions of the standard
+// (e.g., JSON_HAS_FILESYSTEM for C++17 and up), please mention the corresponding
+// version macro in a comment close by, like this:
+// JSON_HAS_CPP_<VERSION> (do not remove; see note at top of file)

 #include "doctest_compatibility.h"

@@ -35,6 +36,25 @@ using nlohmann::json;
 DOCTEST_CLANG_SUPPRESS_WARNING_PUSH
 DOCTEST_CLANG_SUPPRESS_WARNING("-Wexit-time-destructors")

+#if (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464
+    #define JSON_HAS_CPP_17
+    #define JSON_HAS_CPP_14
+#elif (defined(__cplusplus) && __cplusplus >= 201402L) || (defined(_HAS_CXX14) && _HAS_CXX14 == 1)
+    #define JSON_HAS_CPP_14
+#endif
+
+#ifdef JSON_HAS_CPP_17
+    #if __has_include(<optional>)
+        #include <optional>
+    #elif __has_include(<experimental/optional>)
+        #include <experimental/optional>
+    #endif
+#endif
+
+#if defined(JSON_HAS_CPP_17)
+    #include <string_view>
+#endif
+
 TEST_CASE("value conversion")
 {
    SECTION("get a binary value (explicit)")
@@ -660,4 +680,194 @@ TEST_CASE("Strict JSON to enum mapping")
    }
 }

+
+#ifdef JSON_HAS_CPP_17
+#if JSON_HAS_FILESYSTEM || JSON_HAS_EXPERIMENTAL_FILESYSTEM
+TEST_CASE("std::filesystem::path")
+{
+    SECTION("ascii")
+    {
+        json const j_string = "Path";
+        auto p = j_string.template get<nlohmann::detail::std_fs::path>();
+        json const j_path = p;
+
+        CHECK(j_path.template get<std::string>() ==
+              j_string.template get<std::string>());
+    }
+
+    SECTION("utf-8")
+    {
+        json const j_string = "P\xc4\x9b\xc5\xa1ina";
+        auto p = j_string.template get<nlohmann::detail::std_fs::path>();
+        json const j_path = p;
+
+        CHECK(j_path.template get<std::string>() ==
+              j_string.template get<std::string>());
+    }
+}
+#endif
+
+// the ADL to_json overload for std::u8string only exists under the same guard
+// as std::filesystem::path support (it is otherwise only reached indirectly,
+// via std::filesystem::path::u8string()) -- mirror both #if conditions from
+// include/nlohmann/detail/conversions/to_json.hpp exactly
+#if JSON_HAS_FILESYSTEM || JSON_HAS_EXPERIMENTAL_FILESYSTEM
+#if defined(__cpp_lib_char8_t)
+TEST_CASE("std::u8string")
+{
+    SECTION("ascii")
+    {
+        const std::u8string s = u8"Path";
+        json const j = s;
+
+        CHECK(j.template get<std::string>() == "Path");
+    }
+
+    SECTION("utf-8")
+    {
+        // use \u universal-character-names (rather than raw \x byte escapes
+        // or literal non-ASCII source bytes) to compose the multi-byte UTF-8
+        // encoding -- MSVC treats \x escapes used that way inside a u8
+        // literal as a nonstandard extension (warning C5321), which some of
+        // our CI configs promote to an error; \u is portable and produces
+        // the exact same encoded bytes without depending on the source
+        // file's encoding
+        const std::u8string s = u8"P\u011B\u0161ina";
+        json const j = s;
+
+        CHECK(j.template get<std::string>() == "P\xc4\x9b\xc5\xa1ina");
+    }
+}
+#endif
+#endif
+
+#if !defined(JSON_NOEXCEPTION)
+namespace
+{
+// a type whose to_json reports an error by throwing, used below to check that
+// converting a std::optional<T> to JSON propagates an exception thrown while
+// converting its contained value instead of calling std::terminate (#5642)
+struct throwing_to_json_type {};
+
+[[noreturn]] void to_json(json& /*unused*/, const throwing_to_json_type& /*unused*/)
+{
+    throw std::runtime_error("cannot serialize throwing_to_json_type");
+}
+}  // namespace
+#endif
+
+TEST_CASE("std::optional")
+{
+    SECTION("null")
+    {
+        const json j_null;
+        const std::optional<std::string> opt_null;
+
+        CHECK(json(opt_null) == j_null);
+        CHECK(j_null.get<std::optional<std::string>>() == std::nullopt);
+
+        // Constructing std::optional<T> directly from JSON null throws because
+        // std::optional's own converting constructor is chosen over basic_json's
+        // operator T(). This is a language-level limitation (std::optional<T> is
+        // constructible from T, and T is constructible from basic_json via the
+        // operator); there is no SFINAE path that distinguishes "call from inside
+        // std::optional's constructor" from "direct call". Use get<std::optional<T>>()
+        // or get_to() instead for correct null handling. See #4864 and #5246.
+        CHECK_THROWS_WITH_AS(std::optional<std::string>(j_null),
+                             "[json.exception.type_error.302] type must be string, but is null", json::type_error&);
+        CHECK_THROWS_WITH_AS(std::optional<int>(j_null),
+                             "[json.exception.type_error.302] type must be number, but is null", json::type_error&);
+
+        // Assignment goes through the same overload resolution as direct
+        // construction, so it throws for the same reason. This relies on
+        // basic_json's implicit conversion operator, so it only applies
+        // when JSON_USE_IMPLICIT_CONVERSIONS is enabled (the default).
+#if JSON_USE_IMPLICIT_CONVERSIONS
+        std::optional<std::string> opt_assign;
+        CHECK_THROWS_WITH_AS(opt_assign = j_null,
+                             "[json.exception.type_error.302] type must be string, but is null", json::type_error&);
+#endif
+
+        // get_to() is the correct way to obtain std::nullopt from a JSON null.
+        std::optional<std::string> opt_get_to = "placeholder";
+        j_null.get_to(opt_get_to);
+        CHECK(opt_get_to == std::nullopt);
+    }
+
+    SECTION("string")
+    {
+        json j_string = "string";
+        std::optional<std::string> opt_string = "string";
+
+        CHECK(json(opt_string) == j_string);
+        CHECK(std::optional<std::string>(j_string) == opt_string);
+        // false positive: Infer attributes the destruction of the temporaries above to opt_string
+        // @infer-ignore USE_AFTER_DELETE
+    }
+
+    SECTION("bool")
+    {
+        json j_bool = true;
+        std::optional<bool> opt_bool = true;
+
+        CHECK(json(opt_bool) == j_bool);
+        CHECK(std::optional<bool>(j_bool) == opt_bool);
+    }
+
+    SECTION("number")
+    {
+        json j_number = 1;
+        std::optional<int> opt_int = 1;
+
+        CHECK(json(opt_int) == j_number);
+        CHECK(j_number.get<std::optional<int>>() == opt_int);
+    }
+
+    SECTION("array")
+    {
+        json j_array = {1, 2, nullptr};
+        std::vector<std::optional<int>> opt_array = {{1, 2, std::nullopt}};
+
+        CHECK(json(opt_array) == j_array);
+        CHECK(j_array.get<std::vector<std::optional<int>>>() == opt_array);
+    }
+
+    SECTION("object")
+    {
+        json j_object = {{"one", 1}, {"two", 2}, {"zero", nullptr}};
+        std::map<std::string, std::optional<int>> opt_object {{"one", 1}, {"two", 2}, {"zero", std::nullopt}};
+
+        CHECK(json(opt_object) == j_object);
+        CHECK(std::map<std::string, std::optional<int>>(j_object) == opt_object);
+    }
+
+#if !defined(JSON_NOEXCEPTION)
+    SECTION("exception from contained value's to_json propagates (#5642)")
+    {
+        // to_json(BasicJsonType&, const std::optional<T>&) must not be
+        // noexcept: it calls T's to_json, which may throw (a user-defined
+        // to_json that reports an error, or std::bad_alloc for T =
+        // std::string/vector/json). Before the fix, this called
+        // std::terminate() instead of letting the exception propagate.
+        const std::optional<throwing_to_json_type> opt = throwing_to_json_type{};
+        CHECK_THROWS_WITH_AS(json(opt), "cannot serialize throwing_to_json_type", std::runtime_error&);
+
+        // the conversion is noexcept exactly when converting the contained value is
+        // (except with MSVC 2017, where it is never noexcept, see to_json.hpp)
+#if !defined(_MSC_VER) || defined(__clang__) || _MSC_VER >= 1920
+        static_assert(!std::is_nothrow_constructible<json, const std::optional<throwing_to_json_type>&>::value);
+        static_assert(std::is_nothrow_constructible<json, const std::optional<int>&>::value);
+#endif
+    }
+#endif
+}
+#endif
+
+#ifdef JSON_HAS_CPP_17
+    #undef JSON_HAS_CPP_17
+#endif
+
+#ifdef JSON_HAS_CPP_14
+    #undef JSON_HAS_CPP_14
+#endif
 DOCTEST_CLANG_SUPPRESS_WARNING_POP
@@ -9,9 +9,7 @@
 #include "doctest_compatibility.h"

 #include <nlohmann/json.hpp>
-using nlohmann::json;

-#include <cstdint>
 #include <deque>
 #include <map>
 #include <memory>
@@ -166,47 +164,3 @@ TEST_CASE("array type without at()")
    CHECK(j.at(no_at_json::json_pointer("/1")) == 2);
    CHECK_THROWS_AS(j.at(no_at_json::json_pointer("/3")), no_at_json::out_of_range);
 }
-
-TEST_CASE("regression test #5476 - array type without reserve()")
-{
-    // the capacity reserved for definite-length arrays must not require the
-    // array type to have a reserve() member function
-    SECTION("std::deque")
-    {
-        const auto j = deque_json::parse(R"({"a":[1,[2,3]],"b":[]})");
-        CHECK(j.dump() == R"({"a":[1,[2,3]],"b":[]})");
-
-        // the binary formats pass a definite length to start_array()
-        CHECK(deque_json::from_cbor(deque_json::to_cbor(j)) == j);
-        CHECK(deque_json::from_msgpack(deque_json::to_msgpack(j)) == j);
-        CHECK(deque_json::from_bon8(deque_json::to_bon8(j)) == j);
-
-        // parse() instantiates the callback parser as well, which reserves too
-        const auto with_callback = deque_json::parse(R"([1,2,3])", [](int /*depth*/, deque_json::parse_event_t /*event*/, deque_json& /*parsed*/) noexcept
-        {
-            return true;
-        });
-        CHECK(with_callback == deque_json({1, 2, 3}));
-    }
-
-    SECTION("std::vector still reserves")
-    {
-        json array = json::array();
-        for (int i = 0; i < 100; ++i)
-        {
-            array.push_back(i);
-        }
-
-        const auto j = json::from_cbor(json::to_cbor(array));
-        CHECK(j == array);
-        CHECK(j.get_ref<const json::array_t&>().capacity() >= 100);
-    }
-
-    SECTION("the reservation stays capped")
-    {
-        // CBOR array announcing 2^32-1 elements, but truncated right after the
-        // header: the input must be rejected without reserving that capacity
-        const std::vector<std::uint8_t> truncated = {0x9A, 0xFF, 0xFF, 0xFF, 0xFF};
-        CHECK(json::from_cbor(truncated, true, false).is_discarded());
-    }
-}
@@ -44,10 +44,10 @@ TEST_CASE("JSON Node Metadata")
 {
    SECTION("type int")
    {
-        using json_t = json_with_metadata<int>;
-        json_t null;
-        auto obj   = json_t::object();
-        auto array = json_t::array();
+        using json = json_with_metadata<int>;
+        json null;
+        auto obj   = json::object();
+        auto array = json::array();

        null.metadata()  = 1;
        obj.metadata()   = 2;
@@ -61,8 +61,8 @@ TEST_CASE("JSON Node Metadata")
    }
    SECTION("type vector<int>")
    {
-        using json_t = json_with_metadata<std::vector<int>>;
-        json_t value;
+        using json = json_with_metadata<std::vector<int>>;
+        json value;
        value.metadata().emplace_back(1);
        auto copy = value;
        value.metadata().emplace_back(2);
@@ -75,12 +75,12 @@ TEST_CASE("JSON Node Metadata")
    }
    SECTION("copy ctor")
    {
-        using json_t = json_with_metadata<std::vector<int>>;
-        json_t value;
+        using json = json_with_metadata<std::vector<int>>;
+        json value;
        value.metadata().emplace_back(1);
        value.metadata().emplace_back(2);

-        json_t copy = value;
+        json copy = value;

        CHECK(copy.metadata().size()  == 2);
        CHECK(copy.metadata().at(0)   == 1);
@@ -95,12 +95,12 @@ TEST_CASE("JSON Node Metadata")
    }
    SECTION("move ctor")
    {
-        using json_t = json_with_metadata<std::vector<int>>;
-        json_t value;
+        using json = json_with_metadata<std::vector<int>>;
+        json value;
        value.metadata().emplace_back(1);
        value.metadata().emplace_back(2);

-        const json_t moved = std::move(value);
+        const json moved = std::move(value);

        CHECK(moved.metadata().size()  == 2);
        CHECK(moved.metadata().at(0)   == 1);
@@ -108,12 +108,12 @@ TEST_CASE("JSON Node Metadata")
    }
    SECTION("move assign")
    {
-        using json_t = json_with_metadata<std::vector<int>>;
-        json_t value;
+        using json = json_with_metadata<std::vector<int>>;
+        json value;
        value.metadata().emplace_back(1);
        value.metadata().emplace_back(2);

-        json_t moved;
+        json moved;
        moved = std::move(value);

        CHECK(moved.metadata().size()  == 2);
@@ -122,12 +122,12 @@ TEST_CASE("JSON Node Metadata")
    }
    SECTION("copy assign")
    {
-        using json_t = json_with_metadata<std::vector<int>>;
-        json_t value;
+        using json = json_with_metadata<std::vector<int>>;
+        json value;
        value.metadata().emplace_back(1);
        value.metadata().emplace_back(2);

-        json_t copy;
+        json copy;
        copy = value;

        CHECK(copy.metadata().size()  == 2);
@@ -143,8 +143,8 @@ TEST_CASE("JSON Node Metadata")
    }
    SECTION("type unique_ptr<int>")
    {
-        using json_t = json_with_metadata<std::unique_ptr<int>>;
-        json_t value;
+        using json = json_with_metadata<std::unique_ptr<int>>;
+        json value;
        value.metadata().reset(new int(42)); // NOLINT(cppcoreguidelines-owning-memory)
        auto moved = std::move(value);

@@ -153,12 +153,12 @@ TEST_CASE("JSON Node Metadata")
    }
    SECTION("type vector<int> in json array")
    {
-        using json_t = json_with_metadata<std::vector<int>>;
-        json_t value;
+        using json = json_with_metadata<std::vector<int>>;
+        json value;
        value.metadata().emplace_back(1);
        value.metadata().emplace_back(2);

-        json_t const array(10, value);
+        json const array(10, value);

        CHECK(value.metadata().size() == 2);
        CHECK(value.metadata().at(0)  == 1);
@@ -173,10 +173,10 @@ TEST_CASE("JSON Node Metadata")
    }
    SECTION("member swap")
    {
-        using json_t = json_with_metadata<int>;
-        json_t a = 1;
+        using json = json_with_metadata<int>;
+        json a = 1;
        a.metadata() = 100;
-        json_t b = 2;
+        json b = 2;
        b.metadata() = 200;

        a.swap(b);
@@ -188,10 +188,10 @@ TEST_CASE("JSON Node Metadata")
    }
    SECTION("nonmember swap")
    {
-        using json_t = json_with_metadata<int>;
-        json_t a = 1;
+        using json = json_with_metadata<int>;
+        json a = 1;
        a.metadata() = 100;
-        json_t b = 2;
+        json b = 2;
        b.metadata() = 200;

        using std::swap;
@@ -204,10 +204,10 @@ TEST_CASE("JSON Node Metadata")
    }
    SECTION("std::swap")
    {
-        using json_t = json_with_metadata<int>;
-        json_t a = 1;
+        using json = json_with_metadata<int>;
+        json a = 1;
        a.metadata() = 100;
-        json_t b = 2;
+        json b = 2;
        b.metadata() = 200;

        std::swap(a, b);
@@ -221,15 +221,15 @@ TEST_CASE("JSON Node Metadata")
    {
        // std::sort mixes swap() with moves; each value's metadata must
        // travel with it, just as it does for copy, move, and assignment
-        using json_t = json_with_metadata<int>;
-        std::vector<json_t> values;
+        using json = json_with_metadata<int>;
+        std::vector<json> values;
        for (const int v :
                {
                    5, 3, 9, 1, 7, 2, 8, 4, 6, 0, 15, 13, 19, 11, 17, 12, 18, 14, 16, 10,
                    25, 23, 29, 21, 27, 22, 28, 24, 26, 20, 35, 33
                })
        {
-            json_t value = v;
+            json value = v;
            value.metadata() = v;
            values.push_back(value);
        }
@@ -267,19 +267,19 @@ template <class Ptr, class Fnc>
 void visitor_adaptor::do_visit(const Ptr& ptr, const Fnc& fnc) const
 {
    using value_t = nlohmann::detail::value_t;
-    const json_with_visitor_t& self = *static_cast<const json_with_visitor_t*>(this); // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
-    switch (self.type())
+    const json_with_visitor_t& json = *static_cast<const json_with_visitor_t*>(this); // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
+    switch (json.type())
    {
        case value_t::object:
-            for (const auto& entry : self.items())
+            for (const auto& entry : json.items())
            {
                entry.value().do_visit(ptr / entry.key(), fnc);
            }
            break;
        case value_t::array:
-            for (std::size_t i = 0; i < self.size(); ++i)
+            for (std::size_t i = 0; i < json.size(); ++i)
            {
-                self.at(i).do_visit(ptr / std::to_string(i), fnc);
+                json.at(i).do_visit(ptr / std::to_string(i), fnc);
            }
            break;
        case value_t::discarded:
@@ -292,22 +292,22 @@ void visitor_adaptor::do_visit(const Ptr& ptr, const Fnc& fnc) const
        case value_t::number_float:
        case value_t::binary:
        default:
-            fnc(ptr, self);
+            fnc(ptr, json);
    }
 }

 TEST_CASE("JSON Visit Node")
 {
-    json_with_visitor_t root;
-    root["null"];
-    root["int"]  = -1;
-    root["uint"] = 1U;
-    root["float"] = 1.0;
-    root["boolean"] = true;
-    root["string"] = "string";
-    root["array"].push_back(0);
-    root["array"].push_back(1);
-    root["array"].push_back(root);
+    json_with_visitor_t json;
+    json["null"];
+    json["int"]  = -1;
+    json["uint"] = 1U;
+    json["float"] = 1.0;
+    json["boolean"] = true;
+    json["string"] = "string";
+    json["array"].push_back(0);
+    json["array"].push_back(1);
+    json["array"].push_back(json);

    std::set<std::string> expected
    {
@@ -330,7 +330,7 @@ TEST_CASE("JSON Visit Node")
        "/array/2/array/1 - number_integer - 1"
    };

-    root.visit(
+    json.visit(
            [&](const json_with_visitor_t::json_pointer & p,
                const json_with_visitor_t& j)
    {
@@ -374,7 +374,7 @@ TEST_CASE("JSON Visit Node")
                break;
        }
        str << " - "  << j.dump();
-        CHECK(root.at(p) == j);
+        CHECK(json.at(p) == j);
        INFO(str.str());
        CHECK(expected.count(str.str()) == 1);
        expected.erase(str.str());
@@ -404,22 +404,22 @@ using json_with_hidden_base_members = nlohmann::json::with_base_class_t<base_cla

 TEST_CASE("JSON Node as_base_class")
 {
-    using json_t = json_with_hidden_base_members;
+    using json = json_with_hidden_base_members;

-    static_assert(std::is_same<decltype(std::declval<json_t&>().as_base_class()), json_t::json_base_class_t&>::value, "");
-    static_assert(std::is_same<decltype(std::declval<const json_t&>().as_base_class()), const json_t::json_base_class_t&>::value, "");
-    static_assert(noexcept(std::declval<json_t&>().as_base_class()), "");
-    static_assert(noexcept(std::declval<const json_t&>().as_base_class()), "");
+    static_assert(std::is_same<decltype(std::declval<json&>().as_base_class()), json::json_base_class_t&>::value, "");
+    static_assert(std::is_same<decltype(std::declval<const json&>().as_base_class()), const json::json_base_class_t&>::value, "");
+    static_assert(noexcept(std::declval<json&>().as_base_class()), "");
+    static_assert(noexcept(std::declval<const json&>().as_base_class()), "");

    SECTION("non-const")
    {
-        json_t j = {1, 2, 3};
+        json j = {1, 2, 3};

        CHECK(std::string(j.type_name()) == "array");
        CHECK(j.size() == 3);
        CHECK(std::string(j.as_base_class().type_name()) == "custom type_name");
        CHECK(j.as_base_class().size() == 42);
-        CHECK(&j.as_base_class() == &static_cast<json_t::json_base_class_t&>(j));
+        CHECK(&j.as_base_class() == &static_cast<json::json_base_class_t&>(j));

        j.as_base_class().m_size = 7;
        CHECK(j.as_base_class().size() == 7);
@@ -428,13 +428,13 @@ TEST_CASE("JSON Node as_base_class")

    SECTION("const")
    {
-        const json_t j = {1, 2, 3};
+        const json j = {1, 2, 3};

        CHECK(std::string(j.type_name()) == "array");
        CHECK(j.size() == 3);
        CHECK(std::string(j.as_base_class().type_name()) == "custom type_name");
        CHECK(j.as_base_class().size() == 42);
-        CHECK(&j.as_base_class() == &static_cast<const json_t::json_base_class_t&>(j));
+        CHECK(&j.as_base_class() == &static_cast<const json::json_base_class_t&>(j));
    }
 }

@@ -1,111 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-// This file contains the C++17-only part of unit-custom-binary-type.cpp (binary types
-// whose value type is std::byte). It is kept in a separate translation unit so the (much
-// larger) unit-custom-binary-type.cpp is built for C++11 only and not rebuilt for every
-// C++ standard.
-
-#include "doctest_compatibility.h"
-
-// capture whether JSON_DISABLE_ENUM_SERIALIZATION was enabled on the command
-// line before including json.hpp, which #undefs it; std::byte is an enum, so
-// converting std::vector<std::byte> needs enum serialization
-#if defined(JSON_DISABLE_ENUM_SERIALIZATION) && (JSON_DISABLE_ENUM_SERIALIZATION == 1)
-    #define SKIP_TESTS_FOR_ENUM_SERIALIZATION
-#endif
-
-#include <nlohmann/json.hpp>
-
-#ifdef JSON_HAS_CPP_17
-#include <cstddef>
-#include <cstdint>
-#include <functional>
-#include <map>
-#include <memory>
-#include <string>
-#include <vector>
-
-// a BinaryType whose value type is not an integer type at all
-using byte_binary_json = nlohmann::json::with_binary_t<std::vector<std::byte>>;
-
-TEST_CASE("binary type whose value type is not std::uint8_t (C++17)")
-{
-    SECTION("dumping a value type that is not an integer")
-    {
-        const std::vector<std::byte> bytes{std::byte{0}, std::byte{1}, std::byte{0xFF}};
-        CHECK(byte_binary_json::binary(bytes).dump() == R"({"bytes":[0,1,255],"subtype":null})");
-        CHECK(byte_binary_json::binary(bytes, 42).dump() == R"({"bytes":[0,1,255],"subtype":42})");
-        CHECK(byte_binary_json::binary({}).dump() == R"({"bytes":[],"subtype":null})");
-    }
-
-    SECTION("hashing and the binary formats")
-    {
-        const std::vector<std::byte> bytes{std::byte{0}, std::byte{1}, std::byte{0xFF}};
-        const auto j = byte_binary_json::binary(bytes);
-
-        CHECK(std::hash<byte_binary_json> {}(j) == std::hash<byte_binary_json> {}(j));
-        CHECK(byte_binary_json::from_cbor(byte_binary_json::to_cbor(j)) == j);
-        CHECK(byte_binary_json::from_msgpack(byte_binary_json::to_msgpack(j)) == j);
-
-        // UBJSON has no binary type, so binary values are written as an array
-        CHECK(byte_binary_json::from_ubjson(byte_binary_json::to_ubjson(j)) == byte_binary_json({0, 1, 255}));
-        // the same holds for BON8
-        CHECK(byte_binary_json::from_bon8(byte_binary_json::to_bon8(j)) == byte_binary_json({0, 1, 255}));
-    }
-}
-
-// moved from unit-regression3.cpp, so that file does not instantiate a second
-// basic_json specialization (MinGW section limit, see windows.yml)
-TEST_CASE("std::vector<std::byte> as binary type")
-{
-    SECTION("issue #4804: from_cbor incompatible with std::vector<std::byte> as binary_t")
-    {
-        const std::vector<std::uint8_t> data = {0x80};
-        const auto decoded = byte_binary_json::from_cbor(data);
-        CHECK((decoded == byte_binary_json::array()));
-    }
-
-#ifndef SKIP_TESTS_FOR_ENUM_SERIALIZATION
-    SECTION("discussion #4209 - custom BinaryType direct assignment and round-tripping")
-    {
-        // Test that assigning a custom BinaryType directly creates a binary value, not an array
-        const std::vector<std::byte> original{std::byte{1}, std::byte{2}, std::byte{3}};
-        const byte_binary_json j = original;
-        CHECK(j.is_binary());
-        CHECK(!j.is_array());
-
-        // Test round-tripping: extracting the binary value back as the custom container type
-        const auto extracted = j.get<std::vector<std::byte>>();
-        CHECK(extracted == original);
-
-        // Test that the default json alias behavior is unchanged: std::vector<uint8_t> -> array
-        const nlohmann::json default_json = std::vector<std::uint8_t> {1, 2, 3};
-        CHECK(default_json.is_array());
-        CHECK(!default_json.is_binary());
-    }
-
-    SECTION("discussion #4209 - custom BinaryType extraction from parsed array")
-    {
-        // Test that extracting a custom BinaryType from a parsed JSON array still works
-        // (not just from a binary-typed node)
-        const auto j = byte_binary_json::parse("[1,2,3]");
-        CHECK(j.is_array());
-        CHECK(!j.is_binary());
-
-        // Extracting as custom BinaryType should work from arrays
-        const auto extracted = j.get<std::vector<std::byte>>();
-        CHECK(extracted.size() == 3);
-        CHECK(extracted[0] == std::byte{1});
-        CHECK(extracted[1] == std::byte{2});
-        CHECK(extracted[2] == std::byte{3});
-    }
-#endif
-}
-
-#endif
@@ -8,6 +8,13 @@

 #include "doctest_compatibility.h"

+// capture whether JSON_DISABLE_ENUM_SERIALIZATION was enabled on the command
+// line before including json.hpp, which #undefs it; std::byte is an enum, so
+// converting std::vector<std::byte> needs enum serialization
+#if defined(JSON_DISABLE_ENUM_SERIALIZATION) && (JSON_DISABLE_ENUM_SERIALIZATION == 1)
+    #define SKIP_TESTS_FOR_ENUM_SERIALIZATION
+#endif
+
 #include <nlohmann/json.hpp>

 #include <cstdint>
@@ -17,6 +24,10 @@
 #include <string>
 #include <vector>

+#ifdef JSON_HAS_CPP_17
+    #include <cstddef>
+#endif
+
 namespace
 {

@@ -24,6 +35,11 @@ namespace
 // processed as the numbers 0..255
 using char_binary_json = nlohmann::json::with_binary_t<std::vector<char>>;

+#ifdef JSON_HAS_CPP_17
+    // a BinaryType whose value type is not an integer type at all
+    using byte_binary_json = nlohmann::json::with_binary_t<std::vector<std::byte>>;
+#endif
+
 } // namespace

 TEST_CASE("binary type whose value type is not std::uint8_t")
@@ -50,4 +66,79 @@ TEST_CASE("binary type whose value type is not std::uint8_t")
    {
        CHECK(nlohmann::json::binary({0, 1, 255}, 42).dump() == R"({"bytes":[0,1,255],"subtype":42})");
    }
+
+#ifdef JSON_HAS_CPP_17
+    SECTION("dumping a value type that is not an integer")
+    {
+        const std::vector<std::byte> bytes{std::byte{0}, std::byte{1}, std::byte{0xFF}};
+        CHECK(byte_binary_json::binary(bytes).dump() == R"({"bytes":[0,1,255],"subtype":null})");
+        CHECK(byte_binary_json::binary(bytes, 42).dump() == R"({"bytes":[0,1,255],"subtype":42})");
+        CHECK(byte_binary_json::binary({}).dump() == R"({"bytes":[],"subtype":null})");
+    }
+
+    SECTION("hashing and the binary formats")
+    {
+        const std::vector<std::byte> bytes{std::byte{0}, std::byte{1}, std::byte{0xFF}};
+        const auto j = byte_binary_json::binary(bytes);
+
+        CHECK(std::hash<byte_binary_json> {}(j) == std::hash<byte_binary_json> {}(j));
+        CHECK(byte_binary_json::from_cbor(byte_binary_json::to_cbor(j)) == j);
+        CHECK(byte_binary_json::from_msgpack(byte_binary_json::to_msgpack(j)) == j);
+
+        // UBJSON has no binary type, so binary values are written as an array
+        CHECK(byte_binary_json::from_ubjson(byte_binary_json::to_ubjson(j)) == byte_binary_json({0, 1, 255}));
+        // the same holds for BON8
+        CHECK(byte_binary_json::from_bon8(byte_binary_json::to_bon8(j)) == byte_binary_json({0, 1, 255}));
+    }
+#endif
 }
+
+#ifdef JSON_HAS_CPP_17
+// moved from unit-regression3.cpp, so that file does not instantiate a second
+// basic_json specialization (MinGW section limit, see windows.yml)
+TEST_CASE("std::vector<std::byte> as binary type")
+{
+    SECTION("issue #4804: from_cbor incompatible with std::vector<std::byte> as binary_t")
+    {
+        const std::vector<std::uint8_t> data = {0x80};
+        const auto decoded = byte_binary_json::from_cbor(data);
+        CHECK((decoded == byte_binary_json::array()));
+    }
+
+#ifndef SKIP_TESTS_FOR_ENUM_SERIALIZATION
+    SECTION("discussion #4209 - custom BinaryType direct assignment and round-tripping")
+    {
+        // Test that assigning a custom BinaryType directly creates a binary value, not an array
+        const std::vector<std::byte> original{std::byte{1}, std::byte{2}, std::byte{3}};
+        const byte_binary_json j = original;
+        CHECK(j.is_binary());
+        CHECK(!j.is_array());
+
+        // Test round-tripping: extracting the binary value back as the custom container type
+        const auto extracted = j.get<std::vector<std::byte>>();
+        CHECK(extracted == original);
+
+        // Test that the default json alias behavior is unchanged: std::vector<uint8_t> -> array
+        const nlohmann::json default_json = std::vector<std::uint8_t> {1, 2, 3};
+        CHECK(default_json.is_array());
+        CHECK(!default_json.is_binary());
+    }
+
+    SECTION("discussion #4209 - custom BinaryType extraction from parsed array")
+    {
+        // Test that extracting a custom BinaryType from a parsed JSON array still works
+        // (not just from a binary-typed node)
+        const auto j = byte_binary_json::parse("[1,2,3]");
+        CHECK(j.is_array());
+        CHECK(!j.is_binary());
+
+        // Extracting as custom BinaryType should work from arrays
+        const auto extracted = j.get<std::vector<std::byte>>();
+        CHECK(extracted.size() == 3);
+        CHECK(extracted[0] == std::byte{1});
+        CHECK(extracted[1] == std::byte{2});
+        CHECK(extracted[2] == std::byte{3});
+    }
+#endif
+}
+#endif
@@ -1,367 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-#include "doctest_compatibility.h"
-
-#include <nlohmann/json.hpp>
-
-#include <cstdint>
-#include <limits>
-#include <map>
-#include <string>
-#include <type_traits>
-#include <vector>
-
-#if JSON_HAS_THREE_WAY_COMPARISON
-    #include <compare>
-#endif
-
-namespace custom_number_types
-{
-
-// a signed integer of class type: std::is_signed is only true for arithmetic
-// types, so the library has to take the signedness from std::numeric_limits,
-// as it does for 128-bit and multiprecision integer classes such as
-// absl::int128 or boost::multiprecision::cpp_int
-class class_int
-{
-  public:
-    // trivial, like the 128-bit integer classes: the value is stored in a union
-    class_int() = default;
-
-    // implicit from built-in integers and explicit from floats, like absl::int128;
-    // non-template overloads (as absl::int128 has) because clang 3.4 and 3.5
-    // reject basic_json's defaulted data() for a number type with template
-    // constructors
-    class_int(int v) : value(v) {} // NOLINT(google-explicit-constructor,hicpp-explicit-conversions)
-    class_int(unsigned v) : value(v) {} // NOLINT(google-explicit-constructor,hicpp-explicit-conversions)
-    class_int(long v) : value(v) {} // NOLINT(google-explicit-constructor,hicpp-explicit-conversions)
-    class_int(unsigned long v) : value(static_cast<std::int64_t>(v)) {} // NOLINT(google-explicit-constructor,hicpp-explicit-conversions)
-    class_int(long long v) : value(v) {} // NOLINT(google-explicit-constructor,hicpp-explicit-conversions)
-    class_int(unsigned long long v) : value(static_cast<std::int64_t>(v)) {} // NOLINT(google-explicit-constructor,hicpp-explicit-conversions)
-    explicit class_int(double v) : value(static_cast<std::int64_t>(v)) {}
-
-    template<typename T, typename std::enable_if<std::is_arithmetic<T>::value, int>::type = 0>
-    explicit operator T() const
-    {
-        return static_cast<T>(value);
-    }
-
-    friend bool operator==(class_int lhs, class_int rhs)
-    {
-        return lhs.value == rhs.value;
-    }
-    friend bool operator!=(class_int lhs, class_int rhs)
-    {
-        return lhs.value != rhs.value;
-    }
-    friend bool operator<(class_int lhs, class_int rhs)
-    {
-        return lhs.value < rhs.value;
-    }
-#if JSON_HAS_THREE_WAY_COMPARISON
-    friend std::strong_ordering operator<=>(class_int lhs, class_int rhs) // *NOPAD*
-    {
-        return lhs.value <=> rhs.value; // *NOPAD*
-    }
-#endif
-
-  private:
-    std::int64_t value;
-};
-
-} // namespace custom_number_types
-
-using custom_number_types::class_int;
-
-namespace std
-{
-// only the members the library uses
-template<>
-class numeric_limits<class_int>
-{
-  public:
-    static constexpr bool is_signed = true;
-    static constexpr int digits = std::numeric_limits<std::int64_t>::digits;
-};
-} // namespace std
-
-namespace
-{
-
-using class_int_json = nlohmann::basic_json<std::map, std::vector, std::string, bool, class_int, std::uint64_t, double>;
-
-class_int_json make_class_int(std::int64_t v)
-{
-    class_int_json j(class_int_json::value_t::number_integer);
-    j.get_ref<class_int&>() = class_int(v);
-    return j;
-}
-
-} // namespace
-
-// the serializer cannot print an integer of class type, so doctest must not
-// try when an assertion fails
-namespace doctest
-{
-template<>
-struct StringMaker<class_int_json>
-{
-    static String convert(const class_int_json& j)
-    {
-        return j.type_name();
-    }
-};
-} // namespace doctest
-
-// __int128 as number type needs the std::numeric_limits (for the range checks)
-// and std::is_integral (for the serializer) specializations, which libc++
-// always provides and libstdc++ only outside strict ISO modes; the MSVC
-// standard library has none
-#if defined(__SIZEOF_INT128__) && (defined(_LIBCPP_VERSION) || defined(__GLIBCXX_TYPE_INT_N_0))
-    #define JSON_TEST_INT128_NUMBER_TYPES 1
-#else
-    #define JSON_TEST_INT128_NUMBER_TYPES 0
-#endif
-
-#if JSON_TEST_INT128_NUMBER_TYPES
-namespace
-{
-
-// __extension__ keeps -Wpedantic from flagging the non-standard type
-__extension__ typedef __int128 int128; // NOLINT(modernize-use-using)
-__extension__ typedef unsigned __int128 uint128; // NOLINT(modernize-use-using)
-
-static_assert(std::numeric_limits<int128>::digits == 127 && std::numeric_limits<uint128>::digits == 128 &&
-              std::is_integral<int128>::value && std::is_integral<uint128>::value, // NOLINT(misc-redundant-expression)
-              "__int128 is not fully supported by the standard library");
-
-using wide_json = nlohmann::basic_json<std::map, std::vector, std::string, bool, int128, uint128, double>;
-
-wide_json make_int(int128 v)
-{
-    wide_json j(wide_json::value_t::number_integer);
-    j.get_ref<int128&>() = v;
-    return j;
-}
-
-wide_json make_uint(uint128 v)
-{
-    wide_json j(wide_json::value_t::number_unsigned);
-    j.get_ref<uint128&>() = v;
-    return j;
-}
-
-wide_json wrap(const wide_json& value)
-{
-    wide_json o(wide_json::value_t::object);
-    o["v"] = value;
-    return o;
-}
-
-} // namespace
-
-TEST_CASE("custom number types: integers beyond 64 bits")
-{
-    using out_of_range = wide_json::out_of_range;
-
-    const int128 two_64 = static_cast<int128>(1) << 64;
-    const int128 two_100 = static_cast<int128>(1) << 100;
-    const int128 max_int64 = (std::numeric_limits<std::int64_t>::max)();
-    const int128 min_int64 = (std::numeric_limits<std::int64_t>::min)();
-    const uint128 max_uint64 = (std::numeric_limits<std::uint64_t>::max)();
-
-    // before the range checks, these values were silently truncated, e.g.,
-    // 2^100 was written as 0
-    const wide_json int_big = make_int(two_100);
-    const wide_json int_big_negative = make_int(-two_100);
-    const wide_json uint_big = make_uint(static_cast<uint128>(two_100));
-    std::vector<std::uint8_t> _;
-
-    SECTION("CBOR")
-    {
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_cbor(int_big), "[json.exception.out_of_range.407] integer number 1267650600228229401496703205376 cannot be represented by CBOR as it does not fit [-2^64, 2^64-1]", out_of_range&);
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_cbor(int_big_negative), "[json.exception.out_of_range.407] integer number -1267650600228229401496703205376 cannot be represented by CBOR as it does not fit [-2^64, 2^64-1]", out_of_range&);
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_cbor(uint_big), "[json.exception.out_of_range.407] integer number 1267650600228229401496703205376 cannot be represented by CBOR as it does not fit uint64", out_of_range&);
-        // the extremes of the 128-bit types, whose digits are produced without
-        // negating the minimum as a whole
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_cbor(make_int((std::numeric_limits<int128>::min)())), "[json.exception.out_of_range.407] integer number -170141183460469231731687303715884105728 cannot be represented by CBOR as it does not fit [-2^64, 2^64-1]", out_of_range&);
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_cbor(make_int((std::numeric_limits<int128>::max)())), "[json.exception.out_of_range.407] integer number 170141183460469231731687303715884105727 cannot be represented by CBOR as it does not fit [-2^64, 2^64-1]", out_of_range&);
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_cbor(make_uint((std::numeric_limits<uint128>::max)())), "[json.exception.out_of_range.407] integer number 340282366920938463463374607431768211455 cannot be represented by CBOR as it does not fit uint64", out_of_range&);
-        CHECK_THROWS_AS(_ = wide_json::to_cbor(make_int(two_64)), out_of_range&);
-        CHECK_THROWS_AS(_ = wide_json::to_cbor(make_int(-two_64 - 1)), out_of_range&);
-        CHECK_THROWS_AS(_ = wide_json::to_cbor(make_uint(static_cast<uint128>(max_uint64) + 1)), out_of_range&);
-
-        // CBOR's integers cover [-2^64, 2^64-1]
-        CHECK(wide_json::to_cbor(make_int(two_64 - 1)) == std::vector<std::uint8_t>({0x1B, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}));
-        CHECK(wide_json::to_cbor(make_int(-two_64)) == std::vector<std::uint8_t>({0x3B, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}));
-        CHECK(wide_json::to_cbor(make_uint(max_uint64)) == std::vector<std::uint8_t>({0x1B, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}));
-    }
-
-    SECTION("MessagePack")
-    {
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_msgpack(int_big), "[json.exception.out_of_range.407] integer number 1267650600228229401496703205376 cannot be represented by MessagePack as it does not fit [-2^63, 2^64-1]", out_of_range&);
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_msgpack(int_big_negative), "[json.exception.out_of_range.407] integer number -1267650600228229401496703205376 cannot be represented by MessagePack as it does not fit [-2^63, 2^64-1]", out_of_range&);
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_msgpack(uint_big), "[json.exception.out_of_range.407] integer number 1267650600228229401496703205376 cannot be represented by MessagePack as it does not fit uint64", out_of_range&);
-        CHECK_THROWS_AS(_ = wide_json::to_msgpack(make_int(two_64)), out_of_range&);
-        CHECK_THROWS_AS(_ = wide_json::to_msgpack(make_int(min_int64 - 1)), out_of_range&);
-
-        // MessagePack's integers cover [-2^63, 2^64-1]
-        CHECK(wide_json::to_msgpack(make_int(two_64 - 1)) == std::vector<std::uint8_t>({0xCF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}));
-        CHECK(wide_json::to_msgpack(make_int(min_int64)) == std::vector<std::uint8_t>({0xD3, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}));
-        CHECK(wide_json::to_msgpack(make_uint(max_uint64)) == std::vector<std::uint8_t>({0xCF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}));
-    }
-
-    SECTION("BSON")
-    {
-        // wrap() stores the value at /v, which JSON_DIAGNOSTICS adds to the message
-#if JSON_DIAGNOSTICS
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_bson(wrap(int_big)), "[json.exception.out_of_range.407] (/v) integer number 1267650600228229401496703205376 cannot be represented by BSON as it does not fit int64", out_of_range&);
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_bson(wrap(int_big_negative)), "[json.exception.out_of_range.407] (/v) integer number -1267650600228229401496703205376 cannot be represented by BSON as it does not fit int64", out_of_range&);
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_bson(wrap(uint_big)), "[json.exception.out_of_range.407] (/v) integer number 1267650600228229401496703205376 cannot be represented by BSON as it does not fit uint64", out_of_range&);
-#else
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_bson(wrap(int_big)), "[json.exception.out_of_range.407] integer number 1267650600228229401496703205376 cannot be represented by BSON as it does not fit int64", out_of_range&);
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_bson(wrap(int_big_negative)), "[json.exception.out_of_range.407] integer number -1267650600228229401496703205376 cannot be represented by BSON as it does not fit int64", out_of_range&);
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_bson(wrap(uint_big)), "[json.exception.out_of_range.407] integer number 1267650600228229401496703205376 cannot be represented by BSON as it does not fit uint64", out_of_range&);
-#endif
-        CHECK_THROWS_AS(_ = wide_json::to_bson(wrap(make_int(max_int64 + 1))), out_of_range&);
-        CHECK_THROWS_AS(_ = wide_json::to_bson(wrap(make_int(min_int64 - 1))), out_of_range&);
-
-        // nested values are checked as well, before anything is written
-        wide_json nested(wide_json::value_t::object);
-        nested["a"] = wide_json::array({wrap(int_big)});
-        std::vector<std::uint8_t> out;
-        CHECK_THROWS_AS(wide_json::to_bson(nested, out), out_of_range&);
-        CHECK(out.empty());
-
-        CHECK(wide_json::from_bson(wide_json::to_bson(wrap(make_int(max_int64)))) == wrap(make_int(max_int64)));
-        CHECK(wide_json::from_bson(wide_json::to_bson(wrap(make_int(min_int64)))) == wrap(make_int(min_int64)));
-        CHECK_NOTHROW(wide_json::to_bson(wrap(make_uint(max_uint64))));
-    }
-
-    SECTION("BON8")
-    {
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_bon8(int_big), "[json.exception.out_of_range.407] integer number 1267650600228229401496703205376 cannot be represented by BON8 as it does not fit int64", out_of_range&);
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_bon8(int_big_negative), "[json.exception.out_of_range.407] integer number -1267650600228229401496703205376 cannot be represented by BON8 as it does not fit int64", out_of_range&);
-        CHECK_THROWS_WITH_AS(_ = wide_json::to_bon8(uint_big), "[json.exception.out_of_range.407] integer number 1267650600228229401496703205376 cannot be represented by BON8 as it does not fit int64", out_of_range&);
-        CHECK_THROWS_AS(_ = wide_json::to_bon8(make_int(max_int64 + 1)), out_of_range&);
-        CHECK_THROWS_AS(_ = wide_json::to_bon8(make_int(min_int64 - 1)), out_of_range&);
-
-        CHECK(wide_json::from_bon8(wide_json::to_bon8(make_int(max_int64))) == make_int(max_int64));
-        CHECK(wide_json::from_bon8(wide_json::to_bon8(make_int(min_int64))) == make_int(min_int64));
-    }
-
-    SECTION("UBJSON and BJData")
-    {
-        // integers beyond 64 bits are written exactly as high-precision numbers
-        const std::string digits = "1267650600228229401496703205376";
-        std::vector<std::uint8_t> expected = {'H', 'i', static_cast<std::uint8_t>(digits.size())};
-        expected.insert(expected.end(), digits.begin(), digits.end());
-        CHECK(wide_json::to_ubjson(int_big) == expected);
-        CHECK(wide_json::to_ubjson(uint_big) == expected);
-        CHECK(wide_json::to_bjdata(int_big) == expected);
-        // BJData's uint64 marker 'M' was used for any unsigned value beyond
-        // int64, which truncated the ones beyond 64 bits
-        CHECK(wide_json::to_bjdata(uint_big) == expected);
-
-        // the uint64 marker is still used where the value fits
-        CHECK(wide_json::to_bjdata(make_uint(max_uint64)) == std::vector<std::uint8_t>({'M', 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}));
-
-        // the elements of an optimized container are written the same way;
-        // BJData does not allow 'H' as the type of an optimized container
-        std::vector<std::uint8_t> expected_ubjson_array = {'[', '$', 'H', '#', 'i', 2};
-        std::vector<std::uint8_t> expected_bjdata_array = {'[', '#', 'i', 2};
-        for (int i = 0; i < 2; ++i)
-        {
-            expected_ubjson_array.insert(expected_ubjson_array.end(), expected.begin() + 1, expected.end());
-            expected_bjdata_array.insert(expected_bjdata_array.end(), expected.begin(), expected.end());
-        }
-        CHECK(wide_json::to_ubjson(wide_json::array({uint_big, uint_big}), true, true) == expected_ubjson_array);
-        CHECK(wide_json::to_bjdata(wide_json::array({uint_big, uint_big}), true, true) == expected_bjdata_array);
-    }
-
-    SECTION("BJData ND-array")
-    {
-        // an ND-array element beyond 64 bits does not fit any dtype, so the
-        // annotated object is written as a plain object instead of truncating
-        // the element into range
-        wide_json element(wide_json::value_t::object);
-        element["_ArrayType_"] = "uint8";
-        element["_ArraySize_"] = wide_json::array({make_uint(2), make_uint(1)});
-        element["_ArrayData_"] = wide_json::array({make_uint(1), make_uint(static_cast<uint128>(two_64) + 1)});
-        const auto element_bytes = wide_json::to_bjdata(element, true, true);
-        REQUIRE(!element_bytes.empty());
-        CHECK(element_bytes[0] == '{');
-
-        wide_json signed_element = element;
-        signed_element["_ArrayType_"] = "int8";
-        signed_element["_ArrayData_"] = wide_json::array({make_int(1), make_int(-two_64 + 1)});
-        const auto signed_element_bytes = wide_json::to_bjdata(signed_element, true, true);
-        REQUIRE(!signed_element_bytes.empty());
-        CHECK(signed_element_bytes[0] == '{');
-
-        // the same for a dimension beyond 64 bits, which wrapped into a
-        // dimension matching the size of _ArrayData_ (here: 1)
-        wide_json dimension = element;
-        dimension["_ArraySize_"] = wide_json::array({make_uint(2), make_uint(static_cast<uint128>(two_64) + 1)});
-        dimension["_ArrayData_"] = wide_json::array({make_uint(1), make_uint(2)});
-        const auto dimension_bytes = wide_json::to_bjdata(dimension, true, true);
-        REQUIRE(!dimension_bytes.empty());
-        CHECK(dimension_bytes[0] == '{');
-
-        // in range, the ND-array is still written
-        wide_json fits = element;
-        fits["_ArrayData_"] = wide_json::array({make_uint(1), make_uint(2)});
-        const auto fits_bytes = wide_json::to_bjdata(fits, true, true);
-        REQUIRE(!fits_bytes.empty());
-        CHECK(fits_bytes[0] == '[');
-    }
-}
-
-#endif
-
-TEST_CASE("custom number types")
-{
-    SECTION("signed integer of class type compared with a float")
-    {
-        // std::is_signed is false for a class type, which made the comparison
-        // treat any float below zero as less than every integer
-        const class_int_json minus_five = make_class_int(-5);
-        const class_int_json minus_two = make_class_int(-2);
-        const class_int_json five = make_class_int(5);
-        const class_int_json minus_two_and_a_half = -2.5;
-        const class_int_json two_and_a_half = 2.5;
-        const class_int_json huge_negative = -1e30;
-        const class_int_json huge_positive = 1e30;
-
-        CHECK(minus_five < minus_two_and_a_half);
-        CHECK_FALSE(minus_two_and_a_half < minus_five);
-        CHECK(minus_two_and_a_half > minus_five);
-        CHECK(minus_five <= minus_two_and_a_half);
-        CHECK(minus_two_and_a_half >= minus_five);
-        CHECK(minus_five != minus_two_and_a_half);
-
-        CHECK(minus_two_and_a_half < minus_two);
-        CHECK_FALSE(minus_two < minus_two_and_a_half);
-
-        CHECK(two_and_a_half < five);
-        CHECK(minus_five < two_and_a_half);
-
-        // floats beyond the integer's range
-        CHECK(huge_negative < minus_five);
-        CHECK_FALSE(minus_five < huge_negative);
-        CHECK(five < huge_positive);
-        CHECK_FALSE(huge_positive < five);
-
-        // equality
-        const class_int_json minus_two_float = -2.0;
-        CHECK(minus_two == minus_two_float);
-        CHECK(minus_two_float == minus_two);
-    }
-
-}
@@ -1,177 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-// This file contains the C++20-only part of unit-deserialization.cpp (char8_t support:
-// _json with char8_t literals and char8_t input). It is kept in a separate translation
-// unit so the (much larger) unit-deserialization.cpp is built for C++11 only and not
-// rebuilt for every C++ standard.
-
-#include "doctest_compatibility.h"
-
-#include <nlohmann/json.hpp>
-using nlohmann::json;
-#ifdef JSON_TEST_NO_GLOBAL_UDLS
-    using namespace nlohmann::literals; // NOLINT(google-build-using-namespace)
-#endif
-
-#ifdef JSON_HAS_CPP_20
-#include <string>
-#include <vector>
-
-#if defined(__cpp_char8_t) && (__cpp_char8_t >= 201811L)
-namespace
-{
-// copy of SaxEventLogger from unit-deserialization.cpp (renamed to avoid clashes in unity builds)
-struct SaxEventLoggerChar8 : public nlohmann::json_sax<json>
-{
-    bool null() override
-    {
-        events.emplace_back("null()");
-        return true;
-    }
-
-    bool boolean(bool val) override
-    {
-        events.emplace_back(val ? "boolean(true)" : "boolean(false)");
-        return true;
-    }
-
-    bool number_integer(json::number_integer_t val) override
-    {
-        events.push_back("number_integer(" + std::to_string(val) + ")");
-        return true;
-    }
-
-    bool number_unsigned(json::number_unsigned_t val) override
-    {
-        events.push_back("number_unsigned(" + std::to_string(val) + ")");
-        return true;
-    }
-
-    bool number_float(json::number_float_t /*val*/, const std::string& s) override
-    {
-        events.push_back("number_float(" + s + ")");
-        return true;
-    }
-
-    bool string(std::string& val) override
-    {
-        events.push_back("string(" + val + ")");
-        return true;
-    }
-
-    bool binary(json::binary_t& val) override
-    {
-        std::string binary_contents = "binary(";
-        std::string comma_space;
-        for (auto b : val)
-        {
-            binary_contents.append(comma_space);
-            binary_contents.append(std::to_string(static_cast<int>(b)));
-            comma_space = ", ";
-        }
-        binary_contents.append(")");
-        events.push_back(binary_contents);
-        return true;
-    }
-
-    bool start_object(std::size_t elements) override
-    {
-        if (elements == (std::numeric_limits<std::size_t>::max)())
-        {
-            events.emplace_back("start_object()");
-        }
-        else
-        {
-            events.push_back("start_object(" + std::to_string(elements) + ")");
-        }
-        return true;
-    }
-
-    bool key(std::string& val) override
-    {
-        events.push_back("key(" + val + ")");
-        return true;
-    }
-
-    bool end_object() override
-    {
-        events.emplace_back("end_object()");
-        return true;
-    }
-
-    bool start_array(std::size_t elements) override
-    {
-        if (elements == (std::numeric_limits<std::size_t>::max)())
-        {
-            events.emplace_back("start_array()");
-        }
-        else
-        {
-            events.push_back("start_array(" + std::to_string(elements) + ")");
-        }
-        return true;
-    }
-
-    bool end_array() override
-    {
-        events.emplace_back("end_array()");
-        return true;
-    }
-
-    bool parse_error(std::size_t position, const std::string& /*last_token*/, const json::exception& /*ex*/) override
-    {
-        events.push_back("parse_error(" + std::to_string(position) + ")");
-        return false;
-    }
-
-    std::vector<std::string> events {}; // NOLINT(readability-redundant-member-init)
-};
-} // namespace
-
-TEST_CASE_TEMPLATE("deserialization of different character types (ASCII) (C++20)", T, char8_t) // NOLINT(readability-math-missing-parentheses, bugprone-throwing-static-initialization)
-{
-    std::vector<T> const v = {'t', 'r', 'u', 'e'};
-    CHECK(json::parse(v) == json(true));
-    CHECK(json::accept(v));
-
-    SaxEventLoggerChar8 l;
-    CHECK(json::sax_parse(v, &l));
-    CHECK(l.events.size() == 1);
-    CHECK(l.events == std::vector<std::string>({"boolean(true)"}));
-}
-#endif
-
-TEST_CASE("deserialization (C++20)")
-{
-#if defined(__cpp_char8_t)
-    SECTION("Using _json with char8_t literals #4945")
-    {
-        // Regular narrow string literal
-        const auto j1 = R"({"key": "value", "num": 42})"_json;
-        CHECK(j1["key"] == "value");
-        CHECK(j1["num"] == 42);
-
-        // UTF-8 prefixed literal (C++20 and later); the emoji is written as a
-        // \U escape rather than a raw multibyte character so this does not
-        // depend on the compiler's source-file encoding (e.g., MSVC without
-        // /utf-8, or classic ICC, which does not encode non-ASCII narrow
-        // string literals as UTF-8 - compare against a \x-escaped expectation
-        // for the same reason)
-        const auto j2 = u8"{\"emoji\": \"\U0001F600\", \"msg\": \"hello\"}"_json;
-        CHECK(j2["emoji"] == "\xF0\x9F\x98\x80");
-        CHECK(j2["msg"] == "hello");
-
-        const auto j3 = u8R"({"key": "value", "num": 42})"_json;
-        CHECK(j3["key"] == "value");
-        CHECK(j3["num"] == 42);
-    }
-#endif
-}
-
-#endif
@@ -1167,9 +1167,44 @@ TEST_CASE("deserialization")
            CHECK(line == "foo");
        }
    }
+
+    // build with C++20
+    // JSON_HAS_CPP_20
+#if defined(__cpp_char8_t)
+    SECTION("Using _json with char8_t literals #4945")
+    {
+        // Regular narrow string literal
+        const auto j1 = R"({"key": "value", "num": 42})"_json;
+        CHECK(j1["key"] == "value");
+        CHECK(j1["num"] == 42);
+
+        // UTF-8 prefixed literal (C++20 and later); the emoji is written as a
+        // \U escape rather than a raw multibyte character so this does not
+        // depend on the compiler's source-file encoding (e.g., MSVC without
+        // /utf-8, or classic ICC, which does not encode non-ASCII narrow
+        // string literals as UTF-8 - compare against a \x-escaped expectation
+        // for the same reason)
+        const auto j2 = u8"{\"emoji\": \"\U0001F600\", \"msg\": \"hello\"}"_json;
+        CHECK(j2["emoji"] == "\xF0\x9F\x98\x80");
+        CHECK(j2["msg"] == "hello");
+
+        const auto j3 = u8R"({"key": "value", "num": 42})"_json;
+        CHECK(j3["key"] == "value");
+        CHECK(j3["num"] == 42);
+    }
+#endif
 }

-TEST_CASE_TEMPLATE("deserialization of different character types (ASCII)", T, char, wchar_t, char16_t, char32_t) // NOLINT(readability-math-missing-parentheses, bugprone-throwing-static-initialization)
+// select the types to test - char8_t is only available since C++20 if and only
+// if __cpp_char8_t is defined.
+#define TYPE_LIST(...) __VA_ARGS__
+#if defined(__cpp_char8_t) && (__cpp_char8_t >= 201811L)
+    #define ASCII_TYPES TYPE_LIST(char, wchar_t, char16_t, char32_t, char8_t)
+#else
+    #define ASCII_TYPES TYPE_LIST(char, wchar_t, char16_t, char32_t)
+#endif
+
+TEST_CASE_TEMPLATE("deserialization of different character types (ASCII)", T, ASCII_TYPES) // NOLINT(readability-math-missing-parentheses, bugprone-throwing-static-initialization)
 {
    std::vector<T> const v = {'t', 'r', 'u', 'e'};
    CHECK(json::parse(v) == json(true));
@@ -27,9 +27,6 @@ using nlohmann::json;
 DOCTEST_CLANG_SUPPRESS_WARNING_PUSH
 DOCTEST_CLANG_SUPPRESS_WARNING("-Wexit-time-destructors")

-// the types live in a namespace, because the file may be compiled together with other test files
-namespace enum_keyed_maps_default
-{
 enum class cards {kreuz, pik, herz, karo};

 // NOLINTNEXTLINE(misc-use-internal-linkage,misc-const-correctness,cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays) - false positive
@@ -68,7 +65,6 @@ NLOHMANN_JSON_SERIALIZE_ENUM_STRICT(strict_cards,
    {strict_cards::herz, "herz"},
    {strict_cards::karo, "karo"}
 })
-} // namespace enum_keyed_maps_default

 namespace
 {
@@ -86,15 +82,6 @@ struct enum_hash
 // see unit-enum_keyed_maps.cpp for JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS=1
 TEST_CASE("maps with enum keys")
 {
-    // block-scope using-declarations take precedence over same-named types of other files in the same translation unit
-    using enum_keyed_maps_default::cards;
-    using enum_keyed_maps_default::strict_cards;
-    using enum_keyed_maps_default::TaskState;
-    using enum_keyed_maps_default::TS_COMPLETED;
-    using enum_keyed_maps_default::TS_INVALID;
-    using enum_keyed_maps_default::TS_RUNNING;
-    using enum_keyed_maps_default::TS_STOPPED;
-
    using task_map = std::map<TaskState, std::string>;
    using task_umap = std::unordered_map<TaskState, std::string, enum_hash>;
    using task_gmap = std::map<TaskState, std::string, std::greater<TaskState>>;
@@ -6,11 +6,11 @@
 // SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
 // SPDX-License-Identifier: MIT

-// cmake/test.cmake builds a unit test with C++ standards beyond C++11 only if the
-// source file mentions the corresponding version macro. The regression below only
-// showed on C++17, and the whole file is just this explicit instantiation, so it
-// cannot be split: build this file for every standard like the other regression tests:
-// JSON_HAS_CPP_17 JSON_HAS_CPP_20 (do not remove)
+// cmake/test.cmake selects the C++ standard versions with which to build a
+// unit test based on the presence of JSON_HAS_CPP_<VERSION> macros.
+// The regression below only showed on C++17, so build this file for every
+// standard like the other regression tests:
+// JSON_HAS_CPP_17 JSON_HAS_CPP_20 (do not remove; see note at top of file)

 #include "doctest_compatibility.h"

@@ -1,239 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-#include "doctest_compatibility.h"
-
-#include <nlohmann/json.hpp>
-using nlohmann::json;
-
-#include <array>
-#include <cstdint>
-#include <cstdio>
-#include <fstream>
-#include <memory>
-#include <random>
-#include <string>
-#include <thread>
-#include <vector>
-
-// Parsing from a FILE* locks the file once and reads it with the unlocked
-// stdio functions (see JSON_DISABLE_UNLOCKED_FILE_IO). These tests pin that
-// this is not observable: the results are the same, the file is unlocked
-// again when parsing ends - also with an exception - and the same thread can
-// keep using the file while it is locked, e.g., from a SAX callback.
-
-namespace
-{
-// a file name of its own for every run: the test runs for several C++
-// standards and configurations at the same time, in the same directory
-std::string temp_file_name()
-{
-    std::random_device rd;
-    return "unit-file_input-" + std::to_string(rd()) + ".tmp";
-}
-
-using file_ptr = std::unique_ptr<std::FILE, int (*)(std::FILE*)>;
-
-// write @a content to the file @a name and open it for reading
-file_ptr open_with(const char* name, const std::string& content)
-{
-    {
-        std::ofstream file(name, std::ios::binary);
-        file << content;
-    }
-    return {std::fopen(name, "rb"), &std::fclose};
-}
-
-// The stdio lock is recursive, so whether parsing released it can only be
-// seen from another thread: ftrylockfile() fails there while this thread
-// holds the lock. ftrylockfile() is POSIX; elsewhere, the check is skipped.
-#if defined(__GLIBC__) || defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)
-void check_unlocked(std::FILE* f)
-{
-    int result = -1;
-    std::thread other([f, &result]
-    {
-        result = ftrylockfile(f);
-        if (result == 0)
-        {
-            funlockfile(f);
-        }
-    });
-    other.join();
-    CHECK(result == 0);
-}
-#else
-void check_unlocked(std::FILE* /*f*/) {}
-#endif
-
-// SAX consumer that also reads the position of the file it is parsing, which
-// takes the file's lock again on the same thread
-class position_reading_sax : public nlohmann::json_sax<json>
-{
-  public:
-    explicit position_reading_sax(std::FILE* f) : m_file(f) {}
-    position_reading_sax(const position_reading_sax&) = delete;
-    position_reading_sax(position_reading_sax&&) = delete;
-    position_reading_sax& operator=(const position_reading_sax&) = delete;
-    position_reading_sax& operator=(position_reading_sax&&) = delete;
-    ~position_reading_sax() override = default;
-
-    bool null() override
-    {
-        return record();
-    }
-    bool boolean(bool /*val*/) override
-    {
-        return record();
-    }
-    bool number_integer(number_integer_t /*val*/) override
-    {
-        return record();
-    }
-    bool number_unsigned(number_unsigned_t /*val*/) override
-    {
-        return record();
-    }
-    bool number_float(number_float_t /*val*/, const string_t& /*s*/) override
-    {
-        return record();
-    }
-    bool string(string_t& /*val*/) override
-    {
-        return record();
-    }
-    bool binary(binary_t& /*val*/) override
-    {
-        return record();
-    }
-    bool start_object(std::size_t /*elements*/) override
-    {
-        return record();
-    }
-    bool key(string_t& /*val*/) override
-    {
-        return record();
-    }
-    bool end_object() override
-    {
-        return record();
-    }
-    bool start_array(std::size_t /*elements*/) override
-    {
-        return record();
-    }
-    bool end_array() override
-    {
-        return record();
-    }
-    bool parse_error(std::size_t /*position*/, const std::string& /*last_token*/, const nlohmann::detail::exception& /*ex*/) override
-    {
-        return false;
-    }
-
-    const std::vector<long>& positions() const
-    {
-        return m_positions;
-    }
-
-  private:
-    bool record()
-    {
-        m_positions.push_back(std::ftell(m_file));
-        return true;
-    }
-
-    std::FILE* m_file;
-    std::vector<long> m_positions{}; // NOLINT(readability-redundant-member-init)
-};
-}  // namespace
-
-TEST_CASE("parsing from a FILE*")
-{
-    const std::string temp_name = temp_file_name();
-    const char* const name = temp_name.c_str();
-    const std::string input = "{\"a\": [1, -2.5, \"three\", true, null], \"b\": {\"c\": \"caf\xc3\xa9\"}}";
-
-    SECTION("values are the same as when parsing from a string")
-    {
-        const file_ptr f = open_with(name, input);
-        REQUIRE(f != nullptr);
-        CHECK(json::parse(f.get()) == json::parse(input));
-        // the whole input was consumed
-        std::array<char, 8> rest{};
-        CHECK(std::fgets(rest.data(), static_cast<int>(rest.size()), f.get()) == nullptr);
-        check_unlocked(f.get());
-    }
-
-#if !defined(JSON_NOEXCEPTION)
-    SECTION("the file is unlocked after a parse error")
-    {
-        const file_ptr f = open_with(name, "[1, 2, x]");
-        REQUIRE(f != nullptr);
-        json _;
-        CHECK_THROWS_WITH_AS(_ = json::parse(f.get()),
-                             "[json.exception.parse_error.101] parse error at line 1, column 8: syntax error while parsing value - invalid literal; last read: '2, x'",
-                             json::parse_error&);
-        check_unlocked(f.get());
-
-        // the file is still usable: the rest of the input is there
-        std::array<char, 8> rest{};
-        CHECK(std::fgets(rest.data(), static_cast<int>(rest.size()), f.get()) != nullptr);
-        CHECK(std::string(rest.data()) == "]");
-    }
-
-#endif // !defined(JSON_NOEXCEPTION)
-
-    SECTION("the file can be parsed again and read with stdio afterwards")
-    {
-        const file_ptr f = open_with(name, "[1] [2] tail");
-        REQUIRE(f != nullptr);
-
-        // sax_parse with strict == false stops after the first value; an array
-        // ends with its closing bracket, so the space after it is not read
-        json j;
-        nlohmann::detail::json_sax_dom_parser<json, nlohmann::detail::string_input_adapter_type> sax1(j);
-        CHECK(json::sax_parse(f.get(), &sax1, json::input_format_t::json, false));
-        CHECK(j == json({1}));
-        check_unlocked(f.get());
-
-        json k;
-        nlohmann::detail::json_sax_dom_parser<json, nlohmann::detail::string_input_adapter_type> sax2(k);
-        CHECK(json::sax_parse(f.get(), &sax2, json::input_format_t::json, false));
-        CHECK(k == json({2}));
-        check_unlocked(f.get());
-
-        std::array<char, 8> rest{};
-        CHECK(std::fgets(rest.data(), static_cast<int>(rest.size()), f.get()) != nullptr);
-        CHECK(std::string(rest.data()) == " tail");
-    }
-
-    SECTION("the same thread can use the file while it is parsed")
-    {
-        const file_ptr f = open_with(name, "[10, 20, 30]");
-        REQUIRE(f != nullptr);
-        position_reading_sax sax(f.get());
-        CHECK(json::sax_parse(f.get(), &sax));
-        // start_array, three numbers, end_array
-        CHECK(sax.positions().size() == 5);
-        CHECK(sax.positions().front() == 1);
-        check_unlocked(f.get());
-    }
-
-    SECTION("binary formats read from a FILE*")
-    {
-        const json j = {{"string", std::string(300, 'x')}, {"array", {1, 2, 3}}, {"number", 1.5}};
-        const std::vector<std::uint8_t> cbor = json::to_cbor(j);
-        const file_ptr f = open_with(name, std::string(reinterpret_cast<const char*>(cbor.data()), cbor.size()));
-        REQUIRE(f != nullptr);
-        CHECK(json::from_cbor(f.get()) == j);
-        check_unlocked(f.get());
-    }
-
-    static_cast<void>(std::remove(name));
-}
@@ -1,503 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-// The fast paths for contiguous input (bulk string scanning, SWAR searches,
-// UTF-8 prefix validation, the 8-digit number loop, the 8-byte indentation
-// skip, the BSON/BON8 bulk string readers) load several bytes at a time. This
-// test places every input directly in front of (or directly behind) an
-// inaccessible page, so reading even one byte outside the input crashes, with
-// or without sanitizers. ASan alone misses over-reads into the slack of the
-// same heap allocation.
-
-#include "doctest_compatibility.h"
-
-#include <nlohmann/json.hpp>
-using nlohmann::json;
-
-#include <algorithm>
-#include <cstdint>
-#include <cstring>
-#include <string>
-#include <utility>
-#include <vector>
-
-#if defined(_WIN32)
-    #define JSON_TEST_GUARD_PAGE_WINDOWS
-    #ifndef NOMINMAX
-        #define NOMINMAX
-    #endif
-    #ifndef WIN32_LEAN_AND_MEAN
-        #define WIN32_LEAN_AND_MEAN
-    #endif
-    #include <windows.h>
-#elif defined(__unix__) || defined(__APPLE__)
-    #define JSON_TEST_GUARD_PAGE_POSIX
-    #include <sys/mman.h>
-    #include <unistd.h>
-#endif
-
-#if defined(JSON_TEST_GUARD_PAGE_WINDOWS) || defined(JSON_TEST_GUARD_PAGE_POSIX)
-
-namespace
-{
-// Three pages: an inaccessible one, a readable one, an inaccessible one. An
-// input is copied either to the end of the middle page (any read past its last
-// byte faults) or to its start (any read before its first byte faults).
-class guarded_buffer
-{
-  public:
-    guarded_buffer()
-        : page(page_size())
-    {
-#if defined(JSON_TEST_GUARD_PAGE_WINDOWS)
-        void* const p = VirtualAlloc(nullptr, 3 * page, MEM_RESERVE | MEM_COMMIT, PAGE_NOACCESS);
-        REQUIRE(p != nullptr);
-        base = static_cast<unsigned char*>(p);
-        DWORD old_protect = 0;
-        REQUIRE(VirtualProtect(base + page, page, PAGE_READWRITE, &old_protect) != 0);
-#else
-        void* const p = mmap(nullptr, 3 * page, PROT_NONE, MAP_PRIVATE | MAP_ANON, -1, 0);
-        REQUIRE(p != MAP_FAILED);
-        base = static_cast<unsigned char*>(p);
-        REQUIRE(mprotect(base + page, page, PROT_READ | PROT_WRITE) == 0);
-#endif
-    }
-
-    ~guarded_buffer()
-    {
-#if defined(JSON_TEST_GUARD_PAGE_WINDOWS)
-        VirtualFree(base, 0, MEM_RELEASE);
-#else
-        munmap(base, 3 * page);
-#endif
-    }
-
-    guarded_buffer(const guarded_buffer&) = delete;
-    guarded_buffer& operator=(const guarded_buffer&) = delete;
-    guarded_buffer(guarded_buffer&&) = delete;
-    guarded_buffer& operator=(guarded_buffer&&) = delete;
-
-    // copies @a input so its last byte is the last readable byte
-    const std::uint8_t* at_end(const std::string& input)
-    {
-        REQUIRE(input.size() <= page);
-        unsigned char* const first = base + (2 * page) - input.size();
-        std::transform(input.begin(), input.end(), first, [](const char c)
-        {
-            return static_cast<unsigned char>(c);
-        });
-        return first;
-    }
-
-    // copies @a input so its first byte is the first readable byte
-    const std::uint8_t* at_start(const std::string& input)
-    {
-        REQUIRE(input.size() <= page);
-        unsigned char* const first = base + page;
-        std::transform(input.begin(), input.end(), first, [](const char c)
-        {
-            return static_cast<unsigned char>(c);
-        });
-        return first;
-    }
-
-  private:
-    static std::size_t page_size()
-    {
-#if defined(JSON_TEST_GUARD_PAGE_WINDOWS)
-        SYSTEM_INFO info;
-        GetSystemInfo(&info);
-        return static_cast<std::size_t>(info.dwPageSize);
-#else
-        return static_cast<std::size_t>(sysconf(_SC_PAGESIZE));
-#endif
-    }
-
-    std::size_t page = 0;
-    unsigned char* base = nullptr;
-};
-
-// the serialization of the result of @a f, or the exception message; @a f
-// takes the allow_exceptions flag, which is false without exceptions, where
-// an error yields a discarded value instead
-template<typename F>
-std::string outcome(F f)
-{
-#if defined(JSON_NOEXCEPTION)
-    return "value: " + f(false).dump(-1, ' ', false, json::error_handler_t::keep);
-#else
-    try
-    {
-        return "value: " + f(true).dump(-1, ' ', false, json::error_handler_t::keep);
-    }
-    catch (const json::exception& e)
-    {
-        return std::string("error: ") + e.what();
-    }
-#endif
-}
-
-// a SAX handler that only counts events, so sax_parse runs without a DOM
-struct counting_sax : nlohmann::json_sax<json>
-{
-    std::size_t events = 0;
-    std::string error{}; // NOLINT(readability-redundant-member-init)
-
-    bool null() override
-    {
-        return count();
-    }
-    bool boolean(bool /*val*/) override
-    {
-        return count();
-    }
-    bool number_integer(number_integer_t /*val*/) override
-    {
-        return count();
-    }
-    bool number_unsigned(number_unsigned_t /*val*/) override
-    {
-        return count();
-    }
-    bool number_float(number_float_t /*val*/, const string_t& /*s*/) override
-    {
-        return count();
-    }
-    bool string(string_t& /*val*/) override
-    {
-        return count();
-    }
-    bool binary(binary_t& /*val*/) override
-    {
-        return count();
-    }
-    bool start_object(std::size_t /*elements*/) override
-    {
-        return count();
-    }
-    bool key(string_t& /*val*/) override
-    {
-        return count();
-    }
-    bool end_object() override
-    {
-        return count();
-    }
-    bool start_array(std::size_t /*elements*/) override
-    {
-        return count();
-    }
-    bool end_array() override
-    {
-        return count();
-    }
-    bool parse_error(std::size_t position, const std::string& /*last_token*/, const nlohmann::detail::exception& ex) override
-    {
-        error = std::to_string(position) + " " + ex.what();
-        return false;
-    }
-
-  private:
-    bool count()
-    {
-        ++events;
-        return true;
-    }
-};
-
-// all prefixes of each seed, so the input ends at every byte of it
-std::vector<std::string> all_prefixes(const std::vector<std::string>& seeds)
-{
-    std::vector<std::string> result;
-    for (const auto& seed : seeds)
-    {
-        for (std::size_t n = 0; n <= seed.size(); ++n)
-        {
-            result.push_back(seed.substr(0, n));
-        }
-    }
-    return result;
-}
-
-std::vector<std::string> json_seeds()
-{
-    std::vector<std::string> seeds =
-    {
-        // string runs: ASCII, escapes, \u escapes, surrogate pairs
-        "\"abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ\"",
-        R"("ab\ncd\"ef\\gh\u00e4ij\uD83D\uDE00kl\u12")",
-        // 2-, 3- and 4-byte UTF-8 sequences, then invalid UTF-8
-        std::string("\"\xC3\xA4\xE2\x82\xAC\xF0\x9F\x98\x80\xC3\xA4\xE2\x82\xAC\xF0\x9F\x98\x80") + "abcdefgh\"",
-        "\"abcdefgh\xC3\x28 \xED\xA0\x80 \xF4\x90\x80\x80 \xF8 \xC0\xAF\"",
-        std::string("\"abcdefg\x01") + "abcdefgh\"",
-        // numbers, so the 8-digit loop runs up to the end
-        "12345678",
-        "1234567890123456",
-        "12345678901234567890123",
-        "-0.000000001234567890123456789",
-        "3.14159265358979323846264338327950288e+100",
-        "-1.2345678901234567e-12",
-        "1E-5",
-        "[1.5,2e10,-3E-5,0.000000001,123456789012345678]",
-        // literals
-        "[true,false,null]",
-        // comments (only parsed with ignore_comments)
-        "/* comment */ [1, // line comment\n 2] /**/",
-        // a pretty-printed document
-        json::parse(R"({"a": [1, 2.5, "three", {"b": null, "c": [true, false]}], "d": {"e": {"f": {"g": "h"}}}})").dump(4),
-        json::parse(R"({"a": [1, 2.5, "three", {"b": null, "c": [true, false]}], "d": {"e": {"f": {"g": "h"}}}})").dump(8, '\t'),
-    };
-
-    // indentation runs of every length, with and without a closing bracket
-    for (std::size_t n = 0; n <= 20; ++n)
-    {
-        seeds.push_back("[\n" + std::string(n, ' ') + "1,\n" + std::string(n, ' ') + "2\n]");
-    }
-
-    return all_prefixes(seeds);
-}
-
-// a value whose binary serializations contain long strings and keys, numbers
-// of every width, and nested containers
-json binary_document()
-{
-    json j;
-    j["a key that is longer than eight bytes"] = "a string value that is longer than eight bytes";
-    j["\xC3\xA4\xE2\x82\xAC\xF0\x9F\x98\x80"] = "\xF0\x9F\x98\x80\xE2\x82\xAC\xC3\xA4 utf-8 0123456789";
-    j["numbers"] = {0, 1, -1, 255, -256, 65536, -2147483649LL, 4294967296ULL, 1.5, -2.25e100};
-    j["nested"] = {{"x", {{"y", {true, false, nullptr}}}}};
-    j["s"] = "";
-    return j;
-}
-
-// readers for check_binary(), callable with a container or an iterator range
-// followed by the allow_exceptions flag
-#define JSON_TEST_GUARD_PAGE_READER(name, from)                                     \
-    struct name                                                                     \
-    {                                                                               \
-        template<typename... Args>                                                  \
-        json operator()(bool allow_exceptions, Args&& ... args) const               \
-        {                                                                           \
-            return json::from(std::forward<Args>(args)..., true, allow_exceptions); \
-        }                                                                           \
-    };
-JSON_TEST_GUARD_PAGE_READER(read_bson, from_bson)
-JSON_TEST_GUARD_PAGE_READER(read_bon8, from_bon8)
-JSON_TEST_GUARD_PAGE_READER(read_cbor, from_cbor)
-JSON_TEST_GUARD_PAGE_READER(read_msgpack, from_msgpack)
-JSON_TEST_GUARD_PAGE_READER(read_ubjson, from_ubjson)
-JSON_TEST_GUARD_PAGE_READER(read_bjdata, from_bjdata)
-#undef JSON_TEST_GUARD_PAGE_READER
-
-// @a bytes as characters (explicitly converted: the iterator-range constructor
-// would convert implicitly, which -fsanitize=integer reports)
-std::string as_chars(const std::vector<std::uint8_t>& bytes)
-{
-    std::string result;
-    result.reserve(bytes.size());
-    for (const std::uint8_t b : bytes)
-    {
-        result.push_back(static_cast<char>(b));
-    }
-    return result;
-}
-
-// reads every prefix of @a bytes at both ends of the guarded page and from a
-// std::string, which must give the same outcome
-template<typename Reader>
-void check_binary(guarded_buffer& guard, const std::vector<std::uint8_t>& bytes, Reader parse)
-{
-    for (const auto& input : all_prefixes({as_chars(bytes)}))
-    {
-        CAPTURE(input)
-        const std::string expected = outcome([&](bool allow)
-        {
-            return parse(allow, input);
-        });
-        for (int placement = 0; placement < 2; ++placement)
-        {
-            const std::uint8_t* const first = placement == 0 ? guard.at_end(input) : guard.at_start(input);
-            CHECK(outcome([&](bool allow)
-            {
-                return parse(allow, first, first + input.size());
-            }) == expected);
-        }
-    }
-}
-
-// parse_float_native() at both ends of the guarded page, compared bit for bit
-// with converting the same token from a std::string
-template<typename FloatType>
-std::uint64_t float_bits(FloatType value)
-{
-    static_assert(sizeof(FloatType) <= sizeof(std::uint64_t), "unsupported floating-point width");
-    std::uint64_t bits = 0;
-    std::memcpy(&bits, &value, sizeof(value));
-    return bits;
-}
-
-template<typename FloatType>
-void check_float_native(guarded_buffer& guard, const std::string& token)
-{
-    const auto decimal_point = token.find('.');
-    const auto exponent = token.find_first_of("eE");
-    const auto mantissa_end = exponent == std::string::npos ? token.size() : exponent;
-    const auto expected = nlohmann::detail::parse_float_native<FloatType>(token.data(), token.data() + token.size(), decimal_point, mantissa_end);
-    for (int placement = 0; placement < 2; ++placement)
-    {
-        const char* const first = reinterpret_cast<const char*>(placement == 0 ? guard.at_end(token) : guard.at_start(token));
-        const auto value = nlohmann::detail::parse_float_native<FloatType>(first, first + token.size(), decimal_point, mantissa_end);
-        CHECK(float_bits(value) == float_bits(expected));
-    }
-}
-} // namespace
-
-TEST_CASE("guard page")
-{
-    guarded_buffer guard;
-
-    SECTION("string scanning")
-    {
-        // fills that drive each function to a different stop
-        const std::vector<std::string> fills =
-        {
-            std::string(64, 'a'),
-            std::string(64, '"'),
-            std::string(64, '\\'),
-            std::string(64, '\x01'),
-            std::string(64, '\x7F'),
-            std::string(64, '\xFF'),
-        };
-        std::vector<std::string> patterns = fills;
-        {
-            std::string utf8;
-            while (utf8.size() < 64)
-            {
-                utf8 += "\xC3\xA4\xE2\x82\xAC\xF0\x9F\x98\x80" "ab";
-            }
-            patterns.push_back(utf8);
-        }
-        {
-            std::string bytes;
-            for (unsigned int i = 0; i < 64; ++i)
-            {
-                bytes.push_back(static_cast<char>((i * 37u) & 0xFFu));
-            }
-            patterns.push_back(bytes);
-        }
-
-        for (const auto& pattern : patterns)
-        {
-            for (std::size_t n = 0; n <= 64; ++n)
-            {
-                const std::string input = pattern.substr(0, n);
-                for (int placement = 0; placement < 2; ++placement)
-                {
-                    const unsigned char* const p = placement == 0 ? guard.at_end(input) : guard.at_start(input);
-
-                    CHECK(nlohmann::detail::find_string_special(p, n) <= n);
-                    CHECK(nlohmann::detail::find_ascii_copyable_run(p, n) <= n);
-                    CHECK(nlohmann::detail::valid_utf8_prefix(p, n) <= n);
-#if defined(JSON_USE_SIMDUTF) && defined(JSON_HAS_CPP_17)
-                    CHECK(nlohmann::detail::find_string_delimiter(p, n) <= n);
-#endif
-                    CHECK(nlohmann::detail::string_bulk_run(p, n) <= n);
-                    CHECK(nlohmann::detail::scalar_string_bulk_run(p, n) <= n);
-                    for (std::size_t i = 0; i < n; ++i)
-                    {
-                        CHECK(nlohmann::detail::validate_one_utf8(p + i, n - i) <= n - i);
-                    }
-                }
-            }
-        }
-    }
-
-    SECTION("float conversion")
-    {
-        // the lexer converts floats from its token buffer, so the JSON section
-        // below never places a float token at the page boundary; this calls the
-        // conversion directly: the 8-digit loops of parse_float_significand()
-        // and digit_comparison() read up to the end of the token
-        const std::vector<std::string> tokens = all_prefixes(
-        {
-            "1234567812345678123456781234567812345678",
-            "-1.2345678901234567890123456789e-123",
-            "0.00000000000000000000000000000000000001",
-            "98765432.10987654",
-            "123456789012345678901234567890e-30",
-            // halfway between 1 and the next double, then just above it
-            "1.00000000000000011102230246251565404236316680908203125",
-            "1.000000000000000111022302462515654042363166809082031250000000001",
-        });
-        for (const auto& token : tokens)
-        {
-            // only complete number tokens: the conversion expects validated input
-            if (!token.empty() && json::accept(token))
-            {
-                CAPTURE(token)
-                check_float_native<double>(guard, token);
-                check_float_native<float>(guard, token);
-            }
-        }
-    }
-
-    SECTION("JSON")
-    {
-        for (const auto& input : json_seeds())
-        {
-            CAPTURE(input)
-            const std::string expected = outcome([&](bool allow)
-            {
-                return json::parse(input, nullptr, allow);
-            });
-            const std::string expected_comments = outcome([&](bool allow)
-            {
-                return json::parse(input, nullptr, allow, true);
-            });
-            const bool expected_accept = json::accept(input);
-            counting_sax expected_sax;
-            const bool expected_sax_result = json::sax_parse(input, &expected_sax);
-
-            for (int placement = 0; placement < 2; ++placement)
-            {
-                const std::uint8_t* const first = placement == 0 ? guard.at_end(input) : guard.at_start(input);
-                const std::uint8_t* const last = first + input.size();
-
-                CHECK(outcome([&](bool allow)
-                {
-                    return json::parse(first, last, nullptr, allow);
-                }) == expected);
-                CHECK(outcome([&](bool allow)
-                {
-                    return json::parse(first, last, nullptr, allow, true);
-                }) == expected_comments);
-                CHECK(json::accept(first, last) == expected_accept);
-
-                counting_sax sax;
-                CHECK(json::sax_parse(first, last, &sax) == expected_sax_result);
-                CHECK(sax.events == expected_sax.events);
-                CHECK(sax.error == expected_sax.error);
-            }
-        }
-    }
-
-    SECTION("binary formats")
-    {
-        // every prefix ends inside a value, e.g., inside a BSON key or BON8
-        // string without its terminator
-        const json j = binary_document();
-        check_binary(guard, json::to_bson(j), read_bson());
-        check_binary(guard, json::to_bon8(j), read_bon8());
-        check_binary(guard, json::to_cbor(j), read_cbor());
-        check_binary(guard, json::to_msgpack(j), read_msgpack());
-        check_binary(guard, json::to_ubjson(j), read_ubjson());
-        check_binary(guard, json::to_bjdata(j), read_bjdata());
-    }
-}
-
-#endif
@@ -1,122 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-// This file contains the C++20-only part of unit-iterators2.cpp (iterators and
-// std::ranges). It is kept in a separate translation unit so the (much larger) unit-
-// iterators2.cpp is built for C++11 only and not rebuilt for every C++ standard.
-
-#include "doctest_compatibility.h"
-
-#include <nlohmann/json.hpp>
-using nlohmann::json;
-
-#ifdef JSON_HAS_CPP_20
-#include <iterator>
-#include <string>
-#include <string_view>
-#include <type_traits>
-#include <utility>
-
-#if JSON_HAS_RANGES
-    #include <algorithm>
-    #include <ranges>
-#endif
-
-TEST_CASE("iterators 2 (C++20)")
-{
-#if JSON_HAS_RANGES
-    SECTION("ranges")
-    {
-        SECTION("concepts")
-        {
-            using nlohmann::detail::iteration_proxy_value;
-            CHECK(std::bidirectional_iterator<json::iterator>);
-            CHECK(std::input_iterator<iteration_proxy_value<json::iterator>>);
-
-            CHECK(std::is_same<json::iterator, std::ranges::iterator_t<json>>::value);
-            CHECK(std::ranges::bidirectional_range<json>);
-
-            using nlohmann::detail::iteration_proxy;
-            using items_type = decltype(std::declval<json&>().items());
-            CHECK(std::is_same<items_type, iteration_proxy<json::iterator>>::value);
-            CHECK(std::is_same<iteration_proxy_value<json::iterator>, std::ranges::iterator_t<items_type>>::value);
-            CHECK(std::ranges::input_range<items_type>);
-        }
-
-        SECTION("algorithms")
-        {
-            SECTION("copy")
-            {
-                json j{"foo", "bar"};
-                auto j_copied = json::array();
-
-                std::ranges::copy(j, std::back_inserter(j_copied));
-
-                CHECK(j == j_copied);
-            }
-
-            SECTION("find_if")
-            {
-                json j{1, 3, 2, 4};
-                auto j_even = json::array();
-
-#if JSON_USE_IMPLICIT_CONVERSIONS
-                auto it = std::ranges::find_if(j, [](int v) noexcept
-                {
-                    return (v % 2) == 0;
-                });
-#else
-                auto it = std::ranges::find_if(j, [](const json & j) noexcept
-                {
-                    int v;
-                    j.get_to(v);
-                    return (v % 2) == 0;
-                });
-#endif
-
-                CHECK(*it == 2);
-            }
-        }
-
-        SECTION("views")
-        {
-            SECTION("reverse")
-            {
-                json j{1, 2, 3, 4, 5};
-                json j_expected{5, 4, 3, 2, 1};
-
-                auto reversed = j | std::views::reverse;
-                CHECK(reversed == j_expected);
-            }
-
-            SECTION("transform")
-            {
-                json j
-                {
-                    { "a_key", "a_value"},
-                    { "b_key", "b_value"},
-                    { "c_key", "c_value"},
-                };
-                json j_expected{"a_key", "b_key", "c_key"};
-
-                // NOLINTNEXTLINE(fuchsia-trailing-return)
-                auto transformed = j.items() | std::views::transform([](const auto & item) -> std::string_view
-                {
-                    return item.key();
-                });
-                auto j_transformed = json::array();
-                std::ranges::copy(transformed, std::back_inserter(j_transformed));
-
-                CHECK(j_transformed == j_expected);
-            }
-        }
-    }
-#endif
-}
-
-#endif
@@ -6,17 +6,23 @@
 // SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
 // SPDX-License-Identifier: MIT

-// cmake/test.cmake builds a unit test with C++ standards beyond C++11 only if the
-// source file mentions the corresponding version macro. To avoid rebuilding this
-// large file for every standard, tests that depend on the standard version (e.g.,
-// those using JSON_HAS_FILESYSTEM, JSON_HAS_RANGES, or JSON_HAS_THREE_WAY_COMPARISON)
-// go into a separate file unit-iterators2-cpp<NN>.cpp. This file stays C++11-only.
+// cmake/test.cmake selects the C++ standard versions with which to build a
+// unit test based on the presence of JSON_HAS_CPP_<VERSION> macros.
+// When using macros that are only defined for particular versions of the standard
+// (e.g., JSON_HAS_FILESYSTEM for C++17 and up), please mention the corresponding
+// version macro in a comment close by, like this:
+// JSON_HAS_CPP_<VERSION> (do not remove; see note at top of file)

 #include "doctest_compatibility.h"

 #include <nlohmann/json.hpp>
 using nlohmann::json;

+#if JSON_HAS_RANGES
+    #include <algorithm>
+    #include <ranges>
+#endif
+
 TEST_CASE("iterators 2")
 {
    SECTION("iterator comparisons")
@@ -866,4 +872,94 @@ TEST_CASE("iterators 2")
            }
        }
    }
+
+#if JSON_HAS_RANGES
+    // JSON_HAS_CPP_20 (do not remove; see note at top of file)
+    SECTION("ranges")
+    {
+        SECTION("concepts")
+        {
+            using nlohmann::detail::iteration_proxy_value;
+            CHECK(std::bidirectional_iterator<json::iterator>);
+            CHECK(std::input_iterator<iteration_proxy_value<json::iterator>>);
+
+            CHECK(std::is_same<json::iterator, std::ranges::iterator_t<json>>::value);
+            CHECK(std::ranges::bidirectional_range<json>);
+
+            using nlohmann::detail::iteration_proxy;
+            using items_type = decltype(std::declval<json&>().items());
+            CHECK(std::is_same<items_type, iteration_proxy<json::iterator>>::value);
+            CHECK(std::is_same<iteration_proxy_value<json::iterator>, std::ranges::iterator_t<items_type>>::value);
+            CHECK(std::ranges::input_range<items_type>);
+        }
+
+        SECTION("algorithms")
+        {
+            SECTION("copy")
+            {
+                json j{"foo", "bar"};
+                auto j_copied = json::array();
+
+                std::ranges::copy(j, std::back_inserter(j_copied));
+
+                CHECK(j == j_copied);
+            }
+
+            SECTION("find_if")
+            {
+                json j{1, 3, 2, 4};
+                auto j_even = json::array();
+
+#if JSON_USE_IMPLICIT_CONVERSIONS
+                auto it = std::ranges::find_if(j, [](int v) noexcept
+                {
+                    return (v % 2) == 0;
+                });
+#else
+                auto it = std::ranges::find_if(j, [](const json & j) noexcept
+                {
+                    int v;
+                    j.get_to(v);
+                    return (v % 2) == 0;
+                });
+#endif
+
+                CHECK(*it == 2);
+            }
+        }
+
+        SECTION("views")
+        {
+            SECTION("reverse")
+            {
+                json j{1, 2, 3, 4, 5};
+                json j_expected{5, 4, 3, 2, 1};
+
+                auto reversed = j | std::views::reverse;
+                CHECK(reversed == j_expected);
+            }
+
+            SECTION("transform")
+            {
+                json j
+                {
+                    { "a_key", "a_value"},
+                    { "b_key", "b_value"},
+                    { "c_key", "c_value"},
+                };
+                json j_expected{"a_key", "b_key", "c_key"};
+
+                // NOLINTNEXTLINE(fuchsia-trailing-return)
+                auto transformed = j.items() | std::views::transform([](const auto & item) -> std::string_view
+                {
+                    return item.key();
+                });
+                auto j_transformed = json::array();
+                std::ranges::copy(transformed, std::back_inserter(j_transformed));
+
+                CHECK(j_transformed == j_expected);
+            }
+        }
+    }
+#endif
 }
@@ -1,147 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-// This file contains the C++20-only part of unit-json_pointer.cpp (JSON pointer comparison
-// with C++20 rewritten candidates and operator<=>, and char8_t literals). It is kept in a
-// separate translation unit so the (much larger) unit-json_pointer.cpp is built for C++11
-// only and not rebuilt for every C++ standard.
-
-#include "doctest_compatibility.h"
-
-// capture whether JSON_DELETE_DEPRECATED_FUNCTIONS was enabled on the command
-// line *before* including json.hpp, since the library #undefs it once the header
-// has been fully processed (see include/nlohmann/detail/macro_unscope.hpp); the
-// tests of deprecated functions are skipped if these functions are deleted
-#if defined(JSON_DELETE_DEPRECATED_FUNCTIONS) && (JSON_DELETE_DEPRECATED_FUNCTIONS == 1)
-    #define JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
-#endif
-
-#include <nlohmann/json.hpp>
-using nlohmann::json;
-#ifdef JSON_TEST_NO_GLOBAL_UDLS
-    using namespace nlohmann::literals; // NOLINT(google-build-using-namespace)
-#endif
-
-#ifdef JSON_HAS_CPP_20
-#if JSON_HAS_THREE_WAY_COMPARISON
-    #include <compare>
-#endif
-#include <string>
-#include <type_traits>
-
-TEST_CASE("JSON pointers (C++20)")
-{
-    SECTION("equality comparison")
-    {
-        std::string ptr_string{"/foo/bar"};
-        auto ptr1 = json::json_pointer(ptr_string);
-        auto ptr2 = json::json_pointer(ptr_string);
-
-        CHECK(ptr1 == ptr2);
-
-        CHECK_FALSE(ptr1 != ptr2);
-
-#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
-        const char* ptr_cpstring = "/foo/bar";
-        const char ptr_castring[] = "/foo/bar"; // NOLINT(misc-const-correctness,hicpp-avoid-c-arrays,modernize-avoid-c-arrays,cppcoreguidelines-avoid-c-arrays)
-
-        CHECK(ptr1 == "/foo/bar");
-        CHECK(ptr1 == ptr_cpstring);
-        CHECK(ptr1 == ptr_castring);
-        CHECK(ptr1 == ptr_string);
-
-        CHECK("/foo/bar" == ptr1);
-        CHECK(ptr_cpstring == ptr1);
-        CHECK(ptr_castring == ptr1);
-        CHECK(ptr_string == ptr1);
-
-        CHECK_FALSE(ptr1 != "/foo/bar");
-        CHECK_FALSE(ptr1 != ptr_cpstring);
-        CHECK_FALSE(ptr1 != ptr_castring);
-        CHECK_FALSE(ptr1 != ptr_string);
-
-        CHECK_FALSE("/foo/bar" != ptr1);
-        CHECK_FALSE(ptr_cpstring != ptr1);
-        CHECK_FALSE(ptr_castring != ptr1);
-        CHECK_FALSE(ptr_string != ptr1);
-
-        SECTION("exceptions")
-        {
-            CHECK_THROWS_WITH_AS(ptr1 == "foo",
-                                 "[json.exception.parse_error.107] parse error at byte 1: JSON pointer must be empty or begin with '/' - was: 'foo'", json::parse_error&);
-            CHECK_THROWS_WITH_AS("foo" == ptr1,
-                                 "[json.exception.parse_error.107] parse error at byte 1: JSON pointer must be empty or begin with '/' - was: 'foo'", json::parse_error&);
-            CHECK_THROWS_WITH_AS(ptr1 == "/~~",
-                                 "[json.exception.parse_error.108] parse error: escape character '~' must be followed with '0' or '1'", json::parse_error&);
-            CHECK_THROWS_WITH_AS("/~~" == ptr1,
-                                 "[json.exception.parse_error.108] parse error: escape character '~' must be followed with '0' or '1'", json::parse_error&);
-        }
-#endif
-    }
-
-    SECTION("less-than comparison")
-    {
-        auto ptr1 = json::json_pointer("/foo/a");
-        auto ptr2 = json::json_pointer("/foo/b");
-
-#if JSON_HAS_THREE_WAY_COMPARISON
-        CHECK((ptr1 <=> ptr2) == std::strong_ordering::less); // *NOPAD*
-        CHECK(ptr2 > ptr1);
-#endif
-    }
-
-    SECTION("backwards compatibility and mixing")
-    {
-        json j = R"(
-        {
-            "foo": ["bar", "baz"]
-        }
-        )"_json;
-
-        using nlohmann::ordered_json;
-        using json_ptr_str = nlohmann::json_pointer<std::string>;
-        using json_ptr_j = nlohmann::json_pointer<json>;
-        using json_ptr_oj = nlohmann::json_pointer<ordered_json>;
-
-        std::string const ptr_string{"/foo/0"};
-        json_ptr_str ptr{ptr_string};
-        json_ptr_j ptr_j{ptr_string};
-        json_ptr_oj ptr_oj{ptr_string};
-
-        SECTION("equality comparison")
-        {
-            CHECK(ptr == ptr_j);
-            CHECK(ptr == ptr_oj);
-            CHECK(ptr_j == ptr);
-            CHECK(ptr_j == ptr_oj);
-            CHECK(ptr_oj == ptr_j);
-            CHECK(ptr_oj == ptr);
-
-            CHECK_FALSE(ptr != ptr_j);
-            CHECK_FALSE(ptr != ptr_oj);
-            CHECK_FALSE(ptr_j != ptr);
-            CHECK_FALSE(ptr_j != ptr_oj);
-            CHECK_FALSE(ptr_oj != ptr_j);
-            CHECK_FALSE(ptr_oj != ptr);
-        }
-    }
-
-#if defined(__cpp_char8_t)
-    SECTION("Using _json_pointer with char8_t literals #4945")
-    {
-        const json j = R"({"a": {"b": {"c": 123}}})"_json;
-        const auto p1 = "/a/b/c"_json_pointer;
-        CHECK(j[p1] == 123);
-
-        const auto p2 = u8"/a/b/c"_json_pointer;
-        CHECK(j[p2] == 123);
-    }
-#endif
-}
-
-#endif
@@ -779,13 +779,14 @@ TEST_CASE("JSON pointers")
        CHECK(ptr.to_string() == "/object/~1");
    }

-#if !JSON_HAS_THREE_WAY_COMPARISON // with three-way comparison, see unit-json_pointer-cpp20.cpp
    SECTION("equality comparison")
    {
        std::string ptr_string{"/foo/bar"};
        auto ptr1 = json::json_pointer(ptr_string);
        auto ptr2 = json::json_pointer(ptr_string);

+        // build with C++20 to test rewritten candidates
+        // JSON_HAS_CPP_20

        CHECK(ptr1 == ptr2);

@@ -828,7 +829,6 @@ TEST_CASE("JSON pointers")
        }
 #endif
    }
-#endif

    SECTION("less-than comparison")
    {
@@ -838,6 +838,12 @@ TEST_CASE("JSON pointers")
        CHECK(ptr1 < ptr2);
        CHECK_FALSE(ptr2 < ptr1);

+        // build with C++20
+        // JSON_HAS_CPP_20
+#if JSON_HAS_THREE_WAY_COMPARISON
+        CHECK((ptr1 <=> ptr2) == std::strong_ordering::less); // *NOPAD*
+        CHECK(ptr2 > ptr1);
+#endif
    }

    SECTION("usable as map key")
@@ -893,9 +899,10 @@ TEST_CASE("JSON pointers")
        CHECK_FALSE(ptr != ptr_j);
        CHECK_FALSE(ptr != ptr_oj);

-#if !JSON_HAS_THREE_WAY_COMPARISON // with three-way comparison, see unit-json_pointer-cpp20.cpp
        SECTION("equality comparison")
        {
+            // build with C++20 to test rewritten candidates
+            // JSON_HAS_CPP_20

            CHECK(ptr == ptr_j);
            CHECK(ptr == ptr_oj);
@@ -911,7 +918,6 @@ TEST_CASE("JSON pointers")
            CHECK_FALSE(ptr_oj != ptr_j);
            CHECK_FALSE(ptr_oj != ptr);
        }
-#endif
    }

    SECTION("value(json_pointer, default) with ordered_json #5664")
@@ -933,6 +939,19 @@ TEST_CASE("JSON pointers")
        CHECK(j.value(ptr_missing, 42) == 42);
    }

+    // build with C++20
+    // JSON_HAS_CPP_20
+#if defined(__cpp_char8_t)
+    SECTION("Using _json_pointer with char8_t literals #4945")
+    {
+        const json j = R"({"a": {"b": {"c": 123}}})"_json;
+        const auto p1 = "/a/b/c"_json_pointer;
+        CHECK(j[p1] == 123);
+
+        const auto p2 = u8"/a/b/c"_json_pointer;
+        CHECK(j[p2] == 123);
+    }
+#endif
 }

 TEST_CASE("unescaping keeps a '~' that does not start an escape sequence")
@@ -470,31 +470,27 @@ TEST_CASE("json_view")
    {
        using nlohmann::detail::is_detected;

+        // a length is not a flag: parse(ptr, len) would convert len to
+        // allow_exceptions and read ptr as a C string, which need not end
        static_assert(is_detected<parse_call_t, const char*, bool>::value, "parse(ptr, bool) is valid");
        static_assert(is_detected<parse_call_t, const char*, bool, bool, bool>::value, "parse(ptr, bool, bool, bool) is valid");
        static_assert(is_detected<parse_call_t, const char*, const char*>::value, "parse(first, last) is valid");
        static_assert(is_detected<parse_call_t, const char*, const char*, bool>::value, "parse(first, last, bool) is valid");
-        static_assert(is_detected<parse_copy_call_t, const char*, bool>::value, "parse_copy(ptr, bool) is valid");
-        static_assert(is_detected<accept_call_t, const char*, bool>::value, "accept(ptr, bool) is valid");
-        static_assert(is_detected<read_call_t, const char*, bool>::value, "read(ptr, bool) is valid");
-
-        // a length is not a flag: parse(ptr, len) would convert len to
-        // allow_exceptions and read ptr as a C string, which need not end
-        //
-        // MSVC 2015 does not treat selecting a deleted function in decltype as
-        // a substitution failure, so it detects the deleted overloads as
-        // callable; calling them still fails to compile
-#if !(defined(_MSC_VER) && _MSC_VER < 1910)
        static_assert(!is_detected<parse_call_t, const char*, std::size_t>::value, "parse(ptr, len) must not compile");
        static_assert(!is_detected<parse_call_t, const char*, int>::value, "parse(ptr, int) must not compile");
        static_assert(!is_detected<parse_call_t, const char*, char>::value, "parse(ptr, char) must not compile");
        static_assert(!is_detected<parse_call_t, const char*, std::size_t, bool>::value, "parse(ptr, len, bool) must not compile");
        static_assert(!is_detected<parse_call_t, const std::string&, std::size_t>::value, "parse(string, len) must not compile");
        static_assert(!is_detected<parse_call_t, const std::vector<char>&, std::size_t>::value, "parse(vector, len) must not compile");
+
+        static_assert(is_detected<parse_copy_call_t, const char*, bool>::value, "parse_copy(ptr, bool) is valid");
        static_assert(!is_detected<parse_copy_call_t, const char*, std::size_t>::value, "parse_copy(ptr, len) must not compile");
+
+        static_assert(is_detected<accept_call_t, const char*, bool>::value, "accept(ptr, bool) is valid");
        static_assert(!is_detected<accept_call_t, const char*, std::size_t>::value, "accept(ptr, len) must not compile");
+
+        static_assert(is_detected<read_call_t, const char*, bool>::value, "read(ptr, bool) is valid");
        static_assert(!is_detected<read_call_t, const char*, std::size_t>::value, "read(ptr, len) must not compile");
-#endif

        // json_view has no conversion to bool: unlike basic_json's, it would
        // mean "exists", not "is not null"; use is_discarded()
@@ -689,7 +685,7 @@ void check_access(const ordered_json_view& v, const ordered_json& j)
            std::size_t occurrences = 0;
            for (auto other = v.begin(); other != v.end(); ++other)
            {
-                occurrences += other.key() == it.key() ? 1u : 0u;
+                occurrences += other.key() == it.key() ? 1 : 0;
            }
            CHECK(v.count(key) == occurrences);
            // lookups find the first member with the key, which is this one if