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Author SHA1 Message Date
Niels Lohmann d7a7534872 Tests: skip the parse() allocation sweep with MSVC iterator debugging
With _ITERATOR_DEBUG_LEVEL > 0 (MSVC STL debug builds, clang-cl), containers
allocate inside noexcept functions, so a failing allocation terminates the
program: "test case CRASHED: Terminate handler called" in the sax_parse
subcase of #5985. The sweep test of #6000 has the same guard.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-11-02 19:12:26 +01:00
Niels Lohmann eaee875178 json_view: no constant operand in the number dispatch (MSVC C4127)
The `!negative ||` that #6006 added to the digit test of the number scan has
a constant left operand in the template (negative is a template argument), so
MSVC reports C4127 under /WX in builder.hpp(1177). Restore the plain test; the
branch behaves the same.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-11-02 19:12:26 +01:00
Niels Lohmann 3724295333 json_view: a value that is not found has no bytes in its exception context
Keeping the byte range of the root value (#5990) dropped the found flag of
value_path(), but a root has no tokens and is found, while a view of a value
that was removed from the document is not found. Without the flag, the
removed value got the bytes of its stale node, and
"json_view exceptions name the path and the bytes of the value" failed on
the macOS jobs with JSON_DIAGNOSTICS and JSON_DIAGNOSTIC_POSITIONS.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-11-02 19:10:16 +01:00
262 changed files with 4757 additions and 82470 deletions

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@@ -28,7 +28,7 @@ jobs:
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
+4 -4
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@@ -22,7 +22,7 @@ jobs:
runs-on: ubuntu-26.04 runs-on: ubuntu-26.04
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
@@ -46,7 +46,7 @@ jobs:
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
@@ -67,10 +67,10 @@ jobs:
- name: Install astyle - name: Install astyle
run: | run: |
python3 -mvenv venv python3 -mvenv venv
venv/bin/pip3 install --require-hashes -r $MAIN_DIR/tools/astyle/requirements.txt venv/bin/pip3 install -r $MAIN_DIR/tools/astyle/requirements.txt
- name: Install generate_natvis dependencies - name: Install generate_natvis dependencies
run: pip3 install --require-hashes -r $NATVIS_TOOL_DIR/requirements.txt run: pip3 install -r $NATVIS_TOOL_DIR/requirements.txt
- name: Regenerate the tools/macro_builder tables in macro_scope.hpp - name: Regenerate the tools/macro_builder tables in macro_scope.hpp
run: | run: |
+1 -1
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@@ -20,7 +20,7 @@ jobs:
timeout-minutes: 30 timeout-minutes: 30
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
+1 -1
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@@ -13,7 +13,7 @@ jobs:
runs-on: ubuntu-22.04 runs-on: ubuntu-22.04
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
+8 -7
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@@ -27,7 +27,7 @@ jobs:
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
@@ -38,13 +38,14 @@ jobs:
# Initializes the CodeQL tools for scanning. # Initializes the CodeQL tools for scanning.
- name: Initialize CodeQL - name: Initialize CodeQL
uses: github/codeql-action/init@33d7b85da1a04171e211befe2c739303b9a4c066 # v4.39.3 uses: github/codeql-action/init@9b3254085494b55a0f7c4c2b3d2d52cc712ce370 # v4.39.1
with: with:
languages: c-cpp languages: c-cpp
# Analyze the sources without compiling them. Autobuild compiled the
# whole test suite and the resulting database was so large that the # Autobuild attempts to build any compiled languages (C/C++, C#, or Java).
# runner often lost communication with the server while importing it. # If this step fails, then you should remove it and run the build manually (see below)
build-mode: none - name: Autobuild
uses: github/codeql-action/autobuild@9b3254085494b55a0f7c4c2b3d2d52cc712ce370 # v4.39.1
- name: Perform CodeQL Analysis - name: Perform CodeQL Analysis
uses: github/codeql-action/analyze@33d7b85da1a04171e211befe2c739303b9a4c066 # v4.39.3 uses: github/codeql-action/analyze@9b3254085494b55a0f7c4c2b3d2d52cc712ce370 # v4.39.1
@@ -20,7 +20,7 @@ jobs:
pull-requests: write pull-requests: write
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
+1 -1
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@@ -21,7 +21,7 @@ jobs:
runs-on: ubuntu-26.04 runs-on: ubuntu-26.04
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
+2 -2
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@@ -31,7 +31,7 @@ jobs:
security-events: write security-events: write
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
@@ -48,6 +48,6 @@ jobs:
output: 'flawfinder_results.sarif' output: 'flawfinder_results.sarif'
- name: Upload analysis results to GitHub Security tab - name: Upload analysis results to GitHub Security tab
uses: github/codeql-action/upload-sarif@33d7b85da1a04171e211befe2c739303b9a4c066 # v4.39.3 uses: github/codeql-action/upload-sarif@9b3254085494b55a0f7c4c2b3d2d52cc712ce370 # v4.39.1
with: with:
sarif_file: ${{github.workspace}}/flawfinder_results.sarif sarif_file: ${{github.workspace}}/flawfinder_results.sarif
+1 -1
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@@ -54,7 +54,7 @@ jobs:
timeout-minutes: 60 timeout-minutes: 60
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
+1 -1
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@@ -23,7 +23,7 @@ jobs:
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
+1 -1
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@@ -37,7 +37,7 @@ jobs:
runs-on: ubuntu-26.04 runs-on: ubuntu-26.04
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
+2 -2
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@@ -40,7 +40,7 @@ jobs:
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
@@ -80,6 +80,6 @@ jobs:
# Upload the results to GitHub's code scanning dashboard. # Upload the results to GitHub's code scanning dashboard.
- name: "Upload to code-scanning" - name: "Upload to code-scanning"
uses: github/codeql-action/upload-sarif@33d7b85da1a04171e211befe2c739303b9a4c066 # v4.39.3 uses: github/codeql-action/upload-sarif@9b3254085494b55a0f7c4c2b3d2d52cc712ce370 # v4.39.1
with: with:
sarif_file: results.sarif sarif_file: results.sarif
+3 -7
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@@ -36,7 +36,7 @@ jobs:
runs-on: ubuntu-26.04 runs-on: ubuntu-26.04
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
@@ -52,12 +52,8 @@ jobs:
# the old action fell back to, running community rules with no token. # the old action fell back to, running community rules with no token.
# SEMGREP_APP_TOKEN is still passed through so registry auth works if a # SEMGREP_APP_TOKEN is still passed through so registry auth works if a
# token is ever added. # token is ever added.
# The version is pinned, but not by hash: Semgrep pins its own dependencies
# to exact or compatible-release versions, so a hash-pinned lock file broke
# on almost every Dependabot bump of a transitive dependency. Dependabot
# only bumps the semgrep line; pip resolves the rest.
- name: Install Semgrep - name: Install Semgrep
run: python3 -m pip install --user -r cmake/requirements/requirements-semgrep.txt run: python3 -m pip install --user semgrep==1.168.0
# `semgrep scan --sarif` always exits 0 even with findings; continue-on-error # `semgrep scan --sarif` always exits 0 even with findings; continue-on-error
# is a safety net so the SARIF upload still runs if the scan itself errors. # is a safety net so the SARIF upload still runs if the scan itself errors.
@@ -69,7 +65,7 @@ jobs:
# Upload SARIF file generated in previous step # Upload SARIF file generated in previous step
- name: Upload SARIF file - name: Upload SARIF file
uses: github/codeql-action/upload-sarif@33d7b85da1a04171e211befe2c739303b9a4c066 # v4.39.3 uses: github/codeql-action/upload-sarif@9b3254085494b55a0f7c4c2b3d2d52cc712ce370 # v4.39.1
with: with:
sarif_file: semgrep.sarif sarif_file: semgrep.sarif
if: always() if: always()
+1 -1
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@@ -16,7 +16,7 @@ jobs:
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
+25 -25
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@@ -25,7 +25,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Run CMake - name: Run CMake
run: cmake -S . -B build -DJSON_CI=On run: cmake -S . -B build -DJSON_CI=On
- name: Build - name: Build
@@ -38,11 +38,11 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Check that Meson and pkg-config offer the CMake options - name: Check that Meson and pkg-config offer the CMake options
run: make check_build_options run: make check_build_options
- name: Install Meson - name: Install Meson
run: pip install --require-hashes -r cmake/requirements/requirements-meson.txt run: pip install meson
- name: Install with Meson - name: Install with Meson
run: | run: |
meson setup build-meson --prefix=${{ github.workspace }}/install meson setup build-meson --prefix=${{ github.workspace }}/install
@@ -80,7 +80,7 @@ jobs:
runs-on: ubuntu-26.04 runs-on: ubuntu-26.04
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
@@ -92,7 +92,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Run CMake - name: Run CMake
run: cmake -S . -B build -DJSON_CI=On run: cmake -S . -B build -DJSON_CI=On
- name: Build - name: Build
@@ -112,7 +112,7 @@ jobs:
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] 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]
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
@@ -123,7 +123,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Run CMake - name: Run CMake
run: cmake -S . -B build -DJSON_CI=On run: cmake -S . -B build -DJSON_CI=On
- name: Build - name: Build
@@ -142,7 +142,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Run CMake - name: Run CMake
run: cmake -S . -B build -DJSON_CI=On run: cmake -S . -B build -DJSON_CI=On
- name: Build - name: Build
@@ -153,7 +153,7 @@ jobs:
container: ubuntu:24.04 container: ubuntu:24.04
strategy: strategy:
matrix: matrix:
target: [ci_cmake_flags, ci_test_diagnostics, ci_test_diagnostic_positions, ci_test_noexceptions, ci_test_noimplicitconversions, ci_test_legacycomparison, ci_test_noglobaludls, ci_test_disableenumserialization, ci_test_disabletuplereferenceconversion, ci_test_skiplibraryversioncheck, ci_test_simdutf, ci_test_strict_nul_handling, ci_test_delete_deprecated_functions, ci_test_no_thread_local, ci_test_recursion_depth_limit_0] target: [ci_cmake_flags, ci_test_diagnostics, ci_test_diagnostic_positions, ci_test_noexceptions, ci_test_noimplicitconversions, ci_test_legacycomparison, ci_test_noglobaludls, ci_test_disableenumserialization, ci_test_disabletuplereferenceconversion, ci_test_skiplibraryversioncheck, ci_test_simdutf, ci_test_strict_nul_handling, ci_test_delete_deprecated_functions, ci_test_no_thread_local]
steps: steps:
- name: Install build-essential - name: Install build-essential
run: apt-get update ; apt-get install -y build-essential unzip wget git run: apt-get update ; apt-get install -y build-essential unzip wget git
@@ -168,7 +168,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Run CMake - name: Run CMake
run: cmake -S . -B build -DJSON_CI=On run: cmake -S . -B build -DJSON_CI=On
- name: Build - name: Build
@@ -178,7 +178,7 @@ jobs:
runs-on: ubuntu-26.04 runs-on: ubuntu-26.04
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
@@ -244,7 +244,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Run CMake - name: Run CMake
run: CXX=g++-${{ matrix.compiler }} cmake -S . -B build -DJSON_CI=On run: CXX=g++-${{ matrix.compiler }} cmake -S . -B build -DJSON_CI=On
- name: Build - name: Build
@@ -262,7 +262,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Run CMake - name: Run CMake
run: cmake -S . -B build -DJSON_CI=On run: cmake -S . -B build -DJSON_CI=On
- name: Build - name: Build
@@ -279,7 +279,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Disable filesystem support (std::filesystem is unusable) for clang 7 / 8 / 9 / 10 - name: Disable filesystem support (std::filesystem is unusable) for clang 7 / 8 / 9 / 10
run: echo "JSON_FORCED_GLOBAL_COMPILE_OPTIONS=-DJSON_HAS_FILESYSTEM=0;-DJSON_HAS_EXPERIMENTAL_FILESYSTEM=0" >> "$GITHUB_ENV" run: echo "JSON_FORCED_GLOBAL_COMPILE_OPTIONS=-DJSON_HAS_FILESYSTEM=0;-DJSON_HAS_EXPERIMENTAL_FILESYSTEM=0" >> "$GITHUB_ENV"
if: ${{ matrix.compiler == '7' || matrix.compiler == '8' || matrix.compiler == '9' || matrix.compiler == '10' }} if: ${{ matrix.compiler == '7' || matrix.compiler == '8' || matrix.compiler == '9' || matrix.compiler == '10' }}
@@ -299,7 +299,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Run CMake - name: Run CMake
run: cmake -S . -B build -DJSON_CI=On run: cmake -S . -B build -DJSON_CI=On
- name: Build - name: Build
@@ -319,7 +319,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Run CMake - name: Run CMake
run: cmake -S . -B build -DJSON_CI=On run: cmake -S . -B build -DJSON_CI=On
- name: Build with libc++ - name: Build with libc++
@@ -346,7 +346,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Run CMake - name: Run CMake
run: cmake -S . -B build -DJSON_CI=On run: cmake -S . -B build -DJSON_CI=On
- name: Build - name: Build
@@ -366,7 +366,7 @@ jobs:
# import-std support. Its opt-in token is CMake-version-specific, so pin # import-std support. Its opt-in token is CMake-version-specific, so pin
# CMake to the version whose token is set in tests/module_cpp20/CMakeLists.txt. # CMake to the version whose token is set in tests/module_cpp20/CMakeLists.txt.
- name: Get pinned CMake and ninja - name: Get pinned CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
with: with:
cmakeVersion: 4.3.4 cmakeVersion: 4.3.4
# Clang: the std library module is provided by libc++ (the image's libstdc++ # Clang: the std library module is provided by libc++ (the image's libstdc++
@@ -392,7 +392,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Run CMake - name: Run CMake
run: cmake -S . -B build -DJSON_CI=On run: cmake -S . -B build -DJSON_CI=On
- name: Build - name: Build
@@ -409,7 +409,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Run CMake - name: Run CMake
run: cmake -S . -B build -DJSON_CI=On run: cmake -S . -B build -DJSON_CI=On
- name: Build - name: Build
@@ -423,7 +423,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Run CMake - name: Run CMake
run: cmake -S . -B build -DJSON_CI=On run: cmake -S . -B build -DJSON_CI=On
- name: Build - name: Build
@@ -433,7 +433,7 @@ jobs:
runs-on: ubuntu-26.04 runs-on: ubuntu-26.04
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
@@ -443,7 +443,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Run CMake - name: Run CMake
run: cmake -S . -B build -DCMAKE_TOOLCHAIN_FILE=$EMSDK/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake -GNinja run: cmake -S . -B build -DCMAKE_TOOLCHAIN_FILE=$EMSDK/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake -GNinja
- name: Build - name: Build
@@ -456,7 +456,7 @@ jobs:
target: [ci_test_examples, ci_test_build_documentation, ci_test_documentation_mermaid] target: [ci_test_examples, ci_test_build_documentation, ci_test_documentation_mermaid]
steps: steps:
- name: Harden Runner - name: Harden Runner
uses: step-security/harden-runner@46b06cea07f9e64621fdf066ba77ac6915163d43 # v2.22.3 uses: step-security/harden-runner@dc2769abcc0fcfbadfc1df54081c1608579ef6b2 # v2.22.2
with: with:
egress-policy: audit egress-policy: audit
@@ -484,7 +484,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Check that the job runs natively on arm64 - name: Check that the job runs natively on arm64
run: uname -m && test "$(uname -m)" = aarch64 run: uname -m && test "$(uname -m)" = aarch64
- name: Run CMake - name: Run CMake
+2 -2
View File
@@ -90,7 +90,7 @@ jobs:
with: with:
persist-credentials: false persist-credentials: false
- name: Get latest CMake and ninja - name: Get latest CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
- name: Set extra CXX_FLAGS for latest std_version - name: Set extra CXX_FLAGS for latest std_version
# /wd5285 silences C5285 emitted by the bundled third-party doctest.h, which # /wd5285 silences C5285 emitted by the bundled third-party doctest.h, which
# specializes std::tuple (newly diagnosed by the VS2026 v145 toolset) # specializes std::tuple (newly diagnosed by the VS2026 v145 toolset)
@@ -216,7 +216,7 @@ jobs:
# import-std support. Its opt-in token is CMake-version-specific, so pin # import-std support. Its opt-in token is CMake-version-specific, so pin
# CMake to the version whose token is set in tests/module_cpp20/CMakeLists.txt. # CMake to the version whose token is set in tests/module_cpp20/CMakeLists.txt.
- name: Get pinned CMake and ninja - name: Get pinned CMake and ninja
uses: lukka/get-cmake@f86dd60acae0d132056913e248bdabf0e0580b7a # v4.4.5 uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
with: with:
cmakeVersion: 4.3.4 cmakeVersion: 4.3.4
# CMAKE_CXX_FLAGS replaces CMake's MSVC defaults (which include /EHsc), and # CMAKE_CXX_FLAGS replaces CMake's MSVC defaults (which include /EHsc), and
-1
View File
@@ -30,7 +30,6 @@ cc_library(
"include/nlohmann/detail/exceptions.hpp", "include/nlohmann/detail/exceptions.hpp",
"include/nlohmann/detail/hash.hpp", "include/nlohmann/detail/hash.hpp",
"include/nlohmann/detail/input/binary_reader.hpp", "include/nlohmann/detail/input/binary_reader.hpp",
"include/nlohmann/detail/input/contiguous_parser.hpp",
"include/nlohmann/detail/input/input_adapters.hpp", "include/nlohmann/detail/input/input_adapters.hpp",
"include/nlohmann/detail/input/json_sax.hpp", "include/nlohmann/detail/input/json_sax.hpp",
"include/nlohmann/detail/input/lexer.hpp", "include/nlohmann/detail/input/lexer.hpp",
+3272
View File
File diff suppressed because it is too large. Load diff
+18 -1
View File
@@ -1,4 +1,4 @@
.PHONY: all amalgamate check-amalgamation check_build_options pretty install_astyle clean release update_hedley update_hedley_undef BUILD.bazel natvis macro_builder_check run_benchmarks pvs_studio serve_header reuse spdx .PHONY: all amalgamate check-amalgamation check_build_options pretty install_astyle clean ChangeLog.md release update_hedley update_hedley_undef BUILD.bazel natvis macro_builder_check run_benchmarks pvs_studio serve_header reuse spdx
########################################################################## ##########################################################################
# configuration # configuration
@@ -40,6 +40,7 @@ MACRO_SCOPE_HPP=include/nlohmann/detail/macro_scope.hpp
all: all:
@echo "amalgamate - amalgamate files single_include/nlohmann/json{,_fwd,_literals,_view}.hpp from the include/nlohmann sources" @echo "amalgamate - amalgamate files single_include/nlohmann/json{,_fwd,_literals,_view}.hpp from the include/nlohmann sources"
@echo "BUILD.bazel - regenerate the Bazel BUILD file from the include/nlohmann sources" @echo "BUILD.bazel - regenerate the Bazel BUILD file from the include/nlohmann sources"
@echo "ChangeLog.md - generate ChangeLog file"
@echo "check-amalgamation - check whether sources have been amalgamated and BUILD.bazel is up to date" @echo "check-amalgamation - check whether sources have been amalgamated and BUILD.bazel is up to date"
@echo "check_build_options - check that the Meson build and the pkg-config files offer the options of the CMake target" @echo "check_build_options - check that the Meson build and the pkg-config files offer the options of the CMake target"
@echo "clean - remove built files" @echo "clean - remove built files"
@@ -174,6 +175,22 @@ check-amalgamation:
BUILD.bazel: BUILD.bazel:
cmake -P cmake/scripts/gen_bazel_build_file.cmake cmake -P cmake/scripts/gen_bazel_build_file.cmake
##########################################################################
# ChangeLog
##########################################################################
# Create a ChangeLog based on the git log using the GitHub Changelog Generator
# (<https://github.com/github-changelog-generator/github-changelog-generator>).
# variable to control the diffs between the last released version and the current repository state
NEXT_VERSION ?= "unreleased"
ChangeLog.md:
github_changelog_generator -o ChangeLog.md --user nlohmann --project json --simple-list --release-url https://github.com/nlohmann/json/releases/tag/%s --future-release $(NEXT_VERSION)
$(SED) -i 's|https://github.com/nlohmann/json/releases/tag/HEAD|https://github.com/nlohmann/json/tree/HEAD|' ChangeLog.md
$(SED) -i '2i All notable changes to this project will be documented in this file. This project adheres to [Semantic Versioning](http://semver.org/).' ChangeLog.md
########################################################################## ##########################################################################
# Release files # Release files
########################################################################## ##########################################################################
+9 -34
View File
@@ -1,9 +1,4 @@
<a href="https://github.com/nlohmann/json/releases"> [![JSON for Modern C++](docs/mkdocs/docs/images/json.gif)](https://github.com/nlohmann/json/releases)
<picture>
<source media="(prefers-color-scheme: dark)" srcset="docs/mkdocs/docs/images/json-dark.svg">
<img src="docs/mkdocs/docs/images/json-light.svg" alt="JSON for Modern C++: animated feature slideshow">
</picture>
</a>
[![Build Status](https://ci.appveyor.com/api/projects/status/1acb366xfyg3qybk/branch/develop?svg=true)](https://ci.appveyor.com/project/nlohmann/json) [![Build Status](https://ci.appveyor.com/api/projects/status/1acb366xfyg3qybk/branch/develop?svg=true)](https://ci.appveyor.com/project/nlohmann/json)
[![Ubuntu](https://github.com/nlohmann/json/workflows/Ubuntu/badge.svg)](https://github.com/nlohmann/json/actions?query=workflow%3AUbuntu) [![Ubuntu](https://github.com/nlohmann/json/workflows/Ubuntu/badge.svg)](https://github.com/nlohmann/json/actions?query=workflow%3AUbuntu)
@@ -44,7 +39,6 @@
- [Conversions to/from arbitrary types](#arbitrary-types-conversions) - [Conversions to/from arbitrary types](#arbitrary-types-conversions)
- [Specializing enum conversion](#specializing-enum-conversion) - [Specializing enum conversion](#specializing-enum-conversion)
- [Binary formats (BSON, CBOR, MessagePack, UBJSON, BJData, and BON8)](#binary-formats-bson-cbor-messagepack-ubjson-bjdata-and-bon8) - [Binary formats (BSON, CBOR, MessagePack, UBJSON, BJData, and BON8)](#binary-formats-bson-cbor-messagepack-ubjson-bjdata-and-bon8)
- [Zero-copy views](#zero-copy-views)
- [Customers](#customers) - [Customers](#customers)
- [Ecosystem](#ecosystem) - [Ecosystem](#ecosystem)
- [Supported compilers](#supported-compilers) - [Supported compilers](#supported-compilers)
@@ -74,7 +68,7 @@ Other aspects were not so important to us:
- **Memory efficiency**. Each JSON object has an overhead of one pointer (the maximal size of a union) and one enumeration element (1 byte). The default generalization uses the following C++ data types: `std::string` for strings, `int64_t`, `uint64_t` or `double` for numbers, `std::map` for objects, `std::vector` for arrays, and `bool` for Booleans. However, you can template the generalized class `basic_json` to your needs. - **Memory efficiency**. Each JSON object has an overhead of one pointer (the maximal size of a union) and one enumeration element (1 byte). The default generalization uses the following C++ data types: `std::string` for strings, `int64_t`, `uint64_t` or `double` for numbers, `std::map` for objects, `std::vector` for arrays, and `bool` for Booleans. However, you can template the generalized class `basic_json` to your needs.
- **Speed**. There are certainly [faster JSON libraries](https://github.com/miloyip/nativejson-benchmark#parsing-time) out there. However, if your goal is to speed up your development by adding JSON support with a single header, then this library is the way to go. If you know how to use a `std::vector` or `std::map`, you are already set. The [performance](https://json.nlohmann.me/features/performance/) page shows how to get the most out of the library. - **Speed**. There are certainly [faster JSON libraries](https://github.com/miloyip/nativejson-benchmark#parsing-time) out there. However, if your goal is to speed up your development by adding JSON support with a single header, then this library is the way to go. If you know how to use a `std::vector` or `std::map`, you are already set.
See the [contribution guidelines](https://github.com/nlohmann/json/blob/develop/.github/CONTRIBUTING.md#please-dont) for more information. See the [contribution guidelines](https://github.com/nlohmann/json/blob/develop/.github/CONTRIBUTING.md#please-dont) for more information.
@@ -1058,7 +1052,7 @@ struct less_than_32_serializer {
Be **very** careful when reimplementing your serializer, you can stack overflow if you don't pay attention: Be **very** careful when reimplementing your serializer, you can stack overflow if you don't pay attention:
```cpp ```cpp
template <typename T, typename = void> template <typename T, void>
struct bad_serializer struct bad_serializer
{ {
template <typename BasicJsonType> template <typename BasicJsonType>
@@ -1069,10 +1063,10 @@ struct bad_serializer
} }
template <typename BasicJsonType> template <typename BasicJsonType>
static void from_json(const BasicJsonType& j, T& value) { static void to_json(const BasicJsonType& j, T& value) {
// this calls BasicJsonType::json_serializer<T>::from_json(j, value) // this calls BasicJsonType::json_serializer<T>::from_json(j, value)
// if BasicJsonType::json_serializer == bad_serializer ... oops! // if BasicJsonType::json_serializer == bad_serializer ... oops!
value = j.template get<T>(); // oops! value = j.get<T>(); // oops!
} }
}; };
``` ```
@@ -1775,7 +1769,7 @@ I deeply appreciate the help of the following people.
330. [AniketDhemare](https://github.com/AniketDhemare) fixed a version in the documentation. 330. [AniketDhemare](https://github.com/AniketDhemare) fixed a version in the documentation.
331. [Philip Müller](https://github.com/philip-paul-mueller) fixed an example. 331. [Philip Müller](https://github.com/philip-paul-mueller) fixed an example.
332. [Leila Shcheglova](https://github.com/LeilaShcheglova) fixed a warning in a test. 332. [Leila Shcheglova](https://github.com/LeilaShcheglova) fixed a warning in a test.
333. [Alex Prabhat Bara](https://github.com/alexprabhat99) fixed a function name in the documentation and avoided temporary `basic_json` values for CBOR and MessagePack object keys. 333. [Alex Prabhat Bara](https://github.com/alexprabhat99) fixed a function name in the documentation.
334. [laterlaugh](https://github.com/laterlaugh) fixed some typos. 334. [laterlaugh](https://github.com/laterlaugh) fixed some typos.
335. [Yuanhao Jia](https://github.com/MrJia1997) fixed the GDB pretty printer. 335. [Yuanhao Jia](https://github.com/MrJia1997) fixed the GDB pretty printer.
336. [Fallen_Breath](https://github.com/Fallen-Breath) fixed an example for JSON Pointer. 336. [Fallen_Breath](https://github.com/Fallen-Breath) fixed an example for JSON Pointer.
@@ -1853,7 +1847,7 @@ I deeply appreciate the help of the following people.
408. [Luke Banicevic](https://github.com/banaboi) fixed corrupt BSON output for lengths exceeding `INT32_MAX`, cleaned up the BSON writer, and improved the documentation. 408. [Luke Banicevic](https://github.com/banaboi) fixed corrupt BSON output for lengths exceeding `INT32_MAX`, cleaned up the BSON writer, and improved the documentation.
409. [Patrick Armstrong](https://github.com/Patrick10199) updated the CBOR references and the half-precision float assertions. 409. [Patrick Armstrong](https://github.com/Patrick10199) updated the CBOR references and the half-precision float assertions.
410. [Yash Bavadiya](https://github.com/xevrion) added checks to all BSON reads. 410. [Yash Bavadiya](https://github.com/xevrion) added checks to all BSON reads.
411. [hum4nBeing](https://github.com/hum4nBeing) and [AJ369ninja](https://github.com/AJ369ninja) fixed the overflow handling of high-precision numbers in UBJSON. 411. [hum4nBeing](https://github.com/hum4nBeing) fixed the overflow handling of high-precision numbers in UBJSON.
412. [tomatotomata](https://github.com/tomatotomata) added checks for reading CBOR tagged subtypes. 412. [tomatotomata](https://github.com/tomatotomata) added checks for reading CBOR tagged subtypes.
413. [YingqiDuan](https://github.com/YingqiDuan) documented the BSON interoperability. 413. [YingqiDuan](https://github.com/YingqiDuan) documented the BSON interoperability.
414. [KBS](https://github.com/youdie006) documented the standards compliance and the strictness of `parse()` and `operator>>`. 414. [KBS](https://github.com/youdie006) documented the standards compliance and the strictness of `parse()` and `operator>>`.
@@ -1867,26 +1861,6 @@ I deeply appreciate the help of the following people.
422. [Avionic Harshit](https://github.com/avionicharshit-byte) made `diff()` linear when an array shrinks. 422. [Avionic Harshit](https://github.com/avionicharshit-byte) made `diff()` linear when an array shrinks.
423. [Qatadaha Bin Matloob](https://github.com/qatcod) fixed comparisons between integers and floats and fixed unparsable BJData output. 423. [Qatadaha Bin Matloob](https://github.com/qatcod) fixed comparisons between integers and floats and fixed unparsable BJData output.
424. [Wu Shuwen](https://github.com/dajiaohuang) removed an unused include. 424. [Wu Shuwen](https://github.com/dajiaohuang) removed an unused include.
425. [Alexander Lanin](https://github.com/AlexanderLanin) improved the error message of `get_to()` for `const` arguments.
426. [satelliteprogrammer](https://github.com/satelliteprogrammer) added `merge_diff()` to create JSON Merge Patches (RFC 7396).
427. [Jeremy Nimmer](https://github.com/jwnimmer-tri) removed `alwayslink` from the Bazel build.
428. [Dadi Reddy Sai Praneeth Reddy](https://github.com/dsp0redy) made `to_msgpack()` throw when a size exceeds the MessagePack limit.
429. [ayush-singh-0601](https://github.com/ayush-singh-0601) reduced the runtime of the test suite.
430. [Kartikey Negi](https://github.com/ReturnKartikey) fixed the CBOR tag handling of tagged values that are not byte strings.
431. [Michiel van Slobbe](https://github.com/mvanslobbe) sped up the parser by checking for the expected separator first.
432. [Mohd Quamar Tyagi](https://github.com/Tyagiquamar) allowed SAX parsing of tagged CBOR.
433. [fhgffy](https://github.com/fhgffy) rejected NUL bytes in UBJSON and BJData high-precision numbers and fixed a `-Wswitch-enum` warning.
434. [Suyog Verma](https://github.com/commit-msuyog) used MSVC intrinsics for the 128-bit multiplication in the floating-point serialization.
435. [Bas van Dijk](https://github.com/basdedas) fixed a TU-local exposure of `UTF8_ACCEPT` and `UTF8_REJECT` in C++20 modules.
436. [Christoph Grüninger](https://github.com/gruenich) fixed a leak and a crash when an allocation throws during parsing.
437. [Amelia Barnaby](https://github.com/ameliabarnabyhub) made serializing discarded values to binary formats throw instead of writing corrupt output.
438. [Vesko Karaganev](https://github.com/veselink1) made the destructor use the provided allocator.
439. [Michael Sam](https://github.com/michaelsam94) kept allocation failures from escaping the `noexcept` destructor.
440. [Mihnea Magheru](https://github.com/sakuntalle) added a natvis visualizer for `detail::json_default_base`.
441. [Joseph Demarest](https://github.com/JosephDemarest) rejected nested indefinite-length CBOR strings.
442. [Afonso Januário](https://github.com/afonsojanu) made `std::hash<basic_json>` consistent with `operator==` for numbers.
443. [Kartik Gupta](https://github.com/KartikeyG-world) limited the natvis namespace variants to two ABI tags.
444. [manop55555](https://github.com/manop55555) reported a buffer over-read in `dump()` with large indentation values.
Thanks a lot for helping out! Please [let me know](mailto:mail@nlohmann.me) if I forgot someone. Thanks a lot for helping out! Please [let me know](mailto:mail@nlohmann.me) if I forgot someone.
@@ -1909,6 +1883,7 @@ The library itself consists of a single header file licensed under the MIT licen
- [**cpplint**](https://github.com/cpplint/cpplint) for style checks - [**cpplint**](https://github.com/cpplint/cpplint) for style checks
- [**doctest**](https://github.com/doctest/doctest) for the unit tests - [**doctest**](https://github.com/doctest/doctest) for the unit tests
- [**Flawfinder**](https://dwheeler.com/flawfinder/) for static analysis - [**Flawfinder**](https://dwheeler.com/flawfinder/) for static analysis
- [**GitHub Changelog Generator**](https://github.com/github-changelog-generator/github-changelog-generator) to generate the [ChangeLog](https://github.com/nlohmann/json/blob/develop/ChangeLog.md)
- [**Google Benchmark**](https://github.com/google/benchmark) to implement the benchmarks - [**Google Benchmark**](https://github.com/google/benchmark) to implement the benchmarks
- [**Hedley**](https://nemequ.github.io/hedley/) to avoid re-inventing several compiler-agnostic feature macros - [**Hedley**](https://nemequ.github.io/hedley/) to avoid re-inventing several compiler-agnostic feature macros
- [**include-what-you-use**](https://include-what-you-use.org) to check the included headers - [**include-what-you-use**](https://include-what-you-use.org) to check the included headers
@@ -1975,7 +1950,7 @@ For more information, see [JSON With Commas and Comments (JWCC)](https://nigelta
By default, the library does not preserve the **insertion order of object elements**. This is standards-compliant, as the [JSON standard](https://tools.ietf.org/html/rfc8259.html) defines objects as "an unordered collection of zero or more name/value pairs". By default, the library does not preserve the **insertion order of object elements**. This is standards-compliant, as the [JSON standard](https://tools.ietf.org/html/rfc8259.html) defines objects as "an unordered collection of zero or more name/value pairs".
If you do want to preserve the insertion order, you can try the type [`nlohmann::ordered_json`](https://json.nlohmann.me/api/ordered_json/). Alternatively, you can use a more sophisticated ordered map like [`tsl::ordered_map`](https://github.com/Tessil/ordered-map) ([integration](https://github.com/nlohmann/json/issues/546#issuecomment-304447518)) or [`nlohmann::fifo_map`](https://github.com/nlohmann/fifo_map) ([integration](https://github.com/nlohmann/json/issues/485#issuecomment-333652309)). If you do want to preserve the insertion order, you can try the type [`nlohmann::ordered_json`](https://github.com/nlohmann/json/issues/2179). Alternatively, you can use a more sophisticated ordered map like [`tsl::ordered_map`](https://github.com/Tessil/ordered-map) ([integration](https://github.com/nlohmann/json/issues/546#issuecomment-304447518)) or [`nlohmann::fifo_map`](https://github.com/nlohmann/fifo_map) ([integration](https://github.com/nlohmann/json/issues/485#issuecomment-333652309)).
See the [**documentation on object order**](https://json.nlohmann.me/features/object_order/) for more information. See the [**documentation on object order**](https://json.nlohmann.me/features/object_order/) for more information.
-21
View File
@@ -342,27 +342,6 @@ add_custom_target(ci_test_no_thread_local
COMMENT "Compile and test without thread-local storage" COMMENT "Compile and test without thread-local storage"
) )
###############################################################################
# Change the number of levels the walks over a value recurse into.
###############################################################################
# JSON_RECURSION_DEPTH_LIMIT is 128 by default, which is what the whole test
# suite otherwise runs with. 0 sends every walk to its explicit stack at once,
# so this target runs the whole suite through the walks that the default only
# uses for values nested more deeply than 128 levels: results must not depend on
# the limit. The largest limit, 254, is covered by a build of
# tests/src/unit-recursion_depth_limit.cpp (see tests/CMakeLists.txt).
add_custom_target(ci_test_recursion_depth_limit_0
COMMAND ${CMAKE_COMMAND}
-DCMAKE_BUILD_TYPE=Debug -GNinja
-DJSON_BuildTests=ON -DJSON_FastTests=ON
-DCMAKE_CXX_FLAGS=-DJSON_RECURSION_DEPTH_LIMIT=0
-S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_recursion_depth_limit_0
COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_recursion_depth_limit_0
COMMAND cd ${PROJECT_BINARY_DIR}/build_recursion_depth_limit_0 && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
COMMENT "Compile and test with JSON_RECURSION_DEPTH_LIMIT=0"
)
############################################################################### ###############################################################################
# Coverage. # Coverage.
############################################################################### ###############################################################################
-5
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@@ -9,11 +9,6 @@
# __n2)`, which stores `__n1 - __n2` in a signed difference_type and clamps it to int. Any comparison with a shorter # __n2)`, which stores `__n1 - __n2` in a signed difference_type and clamps it to int. Any comparison with a shorter
# view wraps that subtraction on purpose, and -fsanitize=integer reports it as implicit-integer-sign-change. json_view # view wraps that subtraction on purpose, and -fsanitize=integer reports it as implicit-integer-sign-change. json_view
# compares keys as string views, so the same check is excluded for <string_view> as well. # compares keys as string views, so the same check is excluded for <string_view> as well.
# std::filesystem::path::u8string() in libstdc++ 14 builds a std::u8string from the native char sequence, so
# basic_string's range copy (_S_copy_chars) converts every char >= 0x80 to char8_t, which -fsanitize=integer reports as
# implicit-integer-sign-change (test-conversions2_cpp20/cpp23, non-ASCII path). The conversion is intended and happens
# inside the standard library, not in this library.
[implicit-integer-sign-change] [implicit-integer-sign-change]
src:*/include/c++/*/format src:*/include/c++/*/format
src:*/include/c++/*/string_view src:*/include/c++/*/string_view
src:*/include/c++/*/bits/basic_string.h
@@ -1,3 +0,0 @@
meson==1.12.1 \
--hash=sha256:930bc7542cbd9f57009e182fd014eba48cf1a0180a7b9006d2d32d8f168d8b02 \
--hash=sha256:ab0a6ca09f8ef70c564c8241fb5a23957886a0b53fb58412b5e07eaf07dba743
+1 -1
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@@ -1 +1 @@
reuse==6.3.0 reuse==6.2.0
@@ -1 +0,0 @@
semgrep==1.184.0
BIN
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Binary file not shown.

After

Width:  |  Height:  |  Size: 1.6 MiB

+5 -17
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@@ -67,11 +67,7 @@ basic_json(basic_json&& other) noexcept;
- **objects**: [`object_t`](object_t.md) and all kinds of compatible associative containers such as `std::map`, - **objects**: [`object_t`](object_t.md) and all kinds of compatible associative containers such as `std::map`,
`std::unordered_map`, `std::multimap`, and `std::unordered_multimap` with a `key_type` compatible to `string_t` `std::unordered_map`, `std::multimap`, and `std::unordered_multimap` with a `key_type` compatible to `string_t`
and a `value_type` from which a `basic_json` value can be constructed. and a `value_type` from which a `basic_json` value can be constructed.
- **strings**: `string_t`, string literals, and all compatible string containers can be used. Since version 3.13.0, - **strings**: `string_t`, string literals, and all compatible string containers can be used.
this includes `#!cpp std::u8string` (C++20): its code units are stored as a JSON string and
[`get<std::u8string>()`](get.md) reads it back (in version 3.12.0, a `#!cpp std::u8string` was stored as an array
of numbers; `get<std::u8string>()` still accepts such an array). `#!cpp std::u8string_view` and `#!cpp char8_t`
arrays are not strings; they are stored as arrays of code units.
!!! note "Rvalue containers are moved from" !!! note "Rvalue containers are moved from"
@@ -97,18 +93,10 @@ basic_json(basic_json&& other) noexcept;
The constructor tries to convert the internal `m_value` of the parameter. Each member value (object, array, string, The constructor tries to convert the internal `m_value` of the parameter. Each member value (object, array, string,
etc.) is serialized via the corresponding `to_json()` overload. For objects and strings, the conversion requires etc.) is serialized via the corresponding `to_json()` overload. For objects and strings, the conversion requires
that the *target* `basic_json` type's `object_t::key_type` (or `string_t`) be directly constructible from the that the *target* `basic_json` type's `object_t::key_type` (or `string_t`) be directly constructible from the
*source* type's corresponding member type via `is_constructible`. If this requirement is not met, the result *source* type's corresponding member type via `is_constructible`. If this requirement is not met, the conversion
depends on the *source* string type: does not fail to compile; instead, it silently falls back to the array-conversion path, which represents objects
as arrays of `[key, value]` pairs and strings as arrays of character codes. This is a known limitation tracked in
- If it is a range of characters (it has `begin()` and `end()`, as `std::string` does), the conversion falls back to [issue #3425](https://github.com/nlohmann/json/issues/3425).
the array-conversion path, which represents objects as arrays of `[key, value]` pairs and strings as arrays of
character codes. This result has a different type than the source value, so the constructor's
[`JSON_ASSERT`](../macros/json_assert.md) fails; with its default definition, `assert`, the program aborts unless
`NDEBUG` is defined, in which case the array is returned.
- Otherwise, the conversion does not compile, even though `#!cpp std::is_constructible` reports `#!cpp true`; for
example, when converting a `basic_json` whose `string_t` is the `alt_string` of the unit tests to `json`.
This is a known limitation tracked in [issue #3425](https://github.com/nlohmann/json/issues/3425).
5. Creates a JSON value of type array or object from the passed initializer list `init`. In case `type_deduction` is 5. Creates a JSON value of type array or object from the passed initializer list `init`. In case `type_deduction` is
`#!cpp true` (default), the type of the JSON value to be created is deducted from the initializer list `init` `#!cpp true` (default), the type of the JSON value to be created is deducted from the initializer list `init`
-6
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@@ -130,12 +130,6 @@ overload (3).
`#!cpp json(true).get<double>()` throw. This is the behavior of all 3.x versions; `#!cpp json(true).get<double>()` throw. This is the behavior of all 3.x versions;
[`basic_json_view::get<T>()`](../basic_json_view/get.md) behaves the same. [`basic_json_view::get<T>()`](../basic_json_view/get.md) behaves the same.
!!! note "`std::u8string` conversions"
Since version 3.13.0, `#!cpp get<std::u8string>()` (C++20) reads a JSON string; it also accepts an array of numbers,
the form in which version 3.12.0 stored a `#!cpp std::u8string`. Any other JSON type throws
[`type_error.302`](../../home/exceptions.md#jsonexceptiontype_error302) ("type must be string or array").
!!! note "`std::optional` conversions" !!! note "`std::optional` conversions"
Prior to version 3.13.0, `#!cpp get<std::optional<T>>()` (and other conversions to `std::optional<T>`) failed to Prior to version 3.13.0, `#!cpp get<std::optional<T>>()` (and other conversions to `std::optional<T>`) failed to
+2 -2
View File
@@ -50,7 +50,7 @@ Besides `basic_json`, the library offers a second way to hold a parsed JSON text
[`basic_json_document`](../basic_json_document/index.md), which owns or borrows the text and holds a flat index of the [`basic_json_document`](../basic_json_document/index.md), which owns or borrows the text and holds a flat index of the
values in it, and a [`basic_json_view`](../basic_json_view/index.md), a read-only handle to one value of such a document. values in it, and a [`basic_json_view`](../basic_json_view/index.md), a read-only handle to one value of such a document.
Both are defined in the header `<nlohmann/json_view.hpp>`; see Both are defined in the header `<nlohmann/json_view.hpp>`; see
[Zero-copy JSON views](../../features/json_view/index.md) for the concept and the trade-offs. [Zero-copy JSON views](../../features/json_view.md) for the concept and the trade-offs.
- [**json_document**](../json_document.md) / [**ordered_json_document**](../ordered_json_document.md) - read-only - [**json_document**](../json_document.md) / [**ordered_json_document**](../ordered_json_document.md) - read-only
documents of the `basic_json` specialization they belong to documents of the `basic_json` specialization they belong to
@@ -363,7 +363,7 @@ Access to the JSON value
specification of the JSON data interchange format specification of the JSON data interchange format
- [`basic_json_document`](../basic_json_document/index.md) - / [`basic_json_view`](../basic_json_view/index.md) - parse a JSON - [`basic_json_document`](../basic_json_document/index.md) - / [`basic_json_view`](../basic_json_view/index.md) - parse a JSON
text into a flat index and read it through a view text into a flat index and read it through a view
- [Zero-copy JSON views](../../features/json_view/index.md) - when to use a document and a view instead of a `basic_json` - [Zero-copy JSON views](../../features/json_view.md) - when to use a document and a view instead of a `basic_json`
- [Types](../../features/types/index.md) - how JSON values are stored and which types exist - [Types](../../features/types/index.md) - how JSON values are stored and which types exist
- [Converting values](../../features/conversions.md) - get values out of a JSON value and put values in - [Converting values](../../features/conversions.md) - get values out of a JSON value and put values in
- [Creating JSON values](../../features/creating_values.md) - all the ways to build a JSON value - [Creating JSON values](../../features/creating_values.md) - all the ways to build a JSON value
+3 -6
View File
@@ -102,12 +102,9 @@ objects.
When converting an object from one `basic_json` specialization to another via the When converting an object from one `basic_json` specialization to another via the
[converting constructor](basic_json.md) (overload 4), the target `object_t`'s `key_type` must be [converting constructor](basic_json.md) (overload 4), the target `object_t`'s `key_type` must be
directly constructible from the source object's key type (with the default `std::map`, the source `basic_json`'s directly constructible from the source `basic_json`'s `string_t` type (or more generally, from the
`string_t`). If this requirement is not met and the source string type is a range of characters, the source object's key type). If this requirement is not met, the conversion does not fail; instead,
object is converted as an array of key-value pairs, which is incorrect: the converting constructor's the object is silently converted as an array of key-value pairs, which is incorrect. See
[`JSON_ASSERT`](../macros/json_assert.md) fails; with its default definition, `assert`, the program aborts unless
`NDEBUG` is defined, in which case the array is returned. If the source string type is not a range of characters, the
conversion does not compile at all. See [`basic_json`](basic_json.md) and
[issue #3425](https://github.com/nlohmann/json/issues/3425) for details and an example. [issue #3425](https://github.com/nlohmann/json/issues/3425) for details and an example.
## Examples ## Examples
@@ -27,16 +27,6 @@ reference operator+=(initializer_list_t init);
`init` is converted into an object element and added using `operator+=(const typename object_t::value_type&)`. `init` is converted into an object element and added using `operator+=(const typename object_t::value_type&)`.
Otherwise, `init` is converted to a JSON value and added using `operator+=(basic_json&&)`. Otherwise, `init` is converted to a JSON value and added using `operator+=(basic_json&&)`.
!!! note "Single braced JSON value"
For a call such as `#!cpp arr += {obj}`, where the initializer list contains a single JSON value `obj`,
compilers may disagree unless
[`JSON_BRACE_INIT_COPY_SEMANTICS`](../macros/json_brace_init_copy_semantics.md) is defined to `1`: GCC, for
example, selects this overload and appends a single-element array `[obj]`, whereas Clang selects the
`basic_json` overload and appends a copy of `obj`. With the macro, GCC and Clang both append a copy of `obj`.
To get a portable result without the macro, write `#!cpp arr += obj` to append a copy, or
`#!cpp arr += json::array({obj})` to append a single-element array.
## Iterator invalidation ## Iterator invalidation
For all cases where an element is added to an **array**, a reallocation can happen, in which case all iterators (including For all cases where an element is added to an **array**, a reallocation can happen, in which case all iterators (including
@@ -60,14 +60,6 @@ Linear.
2. Comparing a `NaN` with another `NaN`. 2. Comparing a `NaN` with another `NaN`.
3. Comparing a `NaN` and any other number. 3. Comparing a `NaN` and any other number.
For arrays and objects, the elements are compared in order. If the comparison reaches a `NaN` and a number (or
another `NaN`) before any other difference, the result depends on the language standard. Before C++20, the pair
counts as equivalent and the following elements (or the sizes) decide: for instance, `[NaN] < [1, NaN]` and
`[1] <= [NaN]` are `#!cpp true`. Since C++20, the whole comparison is unordered, and `<`, `<=`, `>`, and `>=` all
yield `#!cpp false`. Otherwise (for example `[1, NaN] < [2, NaN]`, or objects whose keys differ), the result is the
same for all language standards. The same program can therefore order such values differently when it is compiled
with a different language standard.
!!! note "Operator overload resolution" !!! note "Operator overload resolution"
Since C++20 overload resolution will consider the _rewritten candidate_ generated from Since C++20 overload resolution will consider the _rewritten candidate_ generated from
@@ -60,14 +60,6 @@ Linear.
2. Comparing a `NaN` with another `NaN`. 2. Comparing a `NaN` with another `NaN`.
3. Comparing a `NaN` and any other number. 3. Comparing a `NaN` and any other number.
For arrays and objects, the elements are compared in order. If the comparison reaches a `NaN` and a number (or
another `NaN`) before any other difference, the result depends on the language standard. Before C++20, the pair
counts as equivalent and the following elements (or the sizes) decide: for instance, `[NaN] < [1, NaN]` and
`[1] <= [NaN]` are `#!cpp true`. Since C++20, the whole comparison is unordered, and `<`, `<=`, `>`, and `>=` all
yield `#!cpp false`. Otherwise (for example `[1, NaN] < [2, NaN]`, or objects whose keys differ), the result is the
same for all language standards. The same program can therefore order such values differently when it is compiled
with a different language standard.
!!! note "Operator overload resolution" !!! note "Operator overload resolution"
Since C++20 overload resolution will consider the _rewritten candidate_ generated from Since C++20 overload resolution will consider the _rewritten candidate_ generated from
@@ -61,14 +61,6 @@ Linear.
2. Comparing a `NaN` with another `NaN`. 2. Comparing a `NaN` with another `NaN`.
3. Comparing a `NaN` and any other number. 3. Comparing a `NaN` and any other number.
For arrays and objects, the elements are compared in order. If the comparison reaches a `NaN` and a number (or
another `NaN`) before any other difference, the result depends on the language standard. Before C++20, the pair
counts as equivalent and the following elements (or the sizes) decide: for instance, `[NaN] < [1, NaN]` and
`[1] <= [NaN]` are `#!cpp true`. Since C++20, the whole comparison is unordered, and `<`, `<=`, `>`, and `>=` all
yield `#!cpp false`. Otherwise (for example `[1, NaN] < [2, NaN]`, or objects whose keys differ), the result is the
same for all language standards. The same program can therefore order such values differently when it is compiled
with a different language standard.
!!! note "Operator overload resolution" !!! note "Operator overload resolution"
Since C++20 overload resolution will consider the _rewritten candidate_ generated from Since C++20 overload resolution will consider the _rewritten candidate_ generated from
@@ -71,14 +71,6 @@ Linear.
2. Comparing a `NaN` with another `NaN`. 2. Comparing a `NaN` with another `NaN`.
3. Comparing a `NaN` and any other number. 3. Comparing a `NaN` and any other number.
For arrays and objects, the elements are compared in order. If the comparison reaches a `NaN` and a number (or
another `NaN`) before any other difference, the result depends on the language standard. Before C++20, the pair
counts as equivalent and the following elements (or the sizes) decide: for instance, `[NaN] < [1, NaN]` and
`[1] <= [NaN]` are `#!cpp true`. Since C++20, the whole comparison is unordered, and `<`, `<=`, `>`, and `>=` all
yield `#!cpp false`. Otherwise (for example `[1, NaN] < [2, NaN]`, or objects whose keys differ), the result is the
same for all language standards. The same program can therefore order such values differently when it is compiled
with a different language standard.
!!! note "Operator overload resolution" !!! note "Operator overload resolution"
Since C++20 overload resolution will consider the _rewritten candidate_ generated from Since C++20 overload resolution will consider the _rewritten candidate_ generated from
@@ -55,10 +55,6 @@ Linear.
1. Comparing a `NaN` with itself. 1. Comparing a `NaN` with itself.
2. Comparing a `NaN` with another `NaN`. 2. Comparing a `NaN` with another `NaN`.
3. Comparing a `NaN` and any other number. 3. Comparing a `NaN` and any other number.
- For arrays and objects, the elements are compared in order. If the comparison reaches a `NaN` and a number (or
another `NaN`) before any other difference, the result is `std::partial_ordering::unordered`. (Without C++20, the
comparison operators `<`, `<=`, `>`, and `>=` use the comparison of the containers, which treats such a pair as
equivalent; see [**operator<**](operator_lt.md).)
## Examples ## Examples
+6 -12
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@@ -124,19 +124,17 @@ outside of a string, invalid) byte; see the [FAQ entry](../../home/faq.md#nul-by
[`basic_json_document::parse`](../basic_json_document/parse.md) accepts the same inputs and the same options, but [`basic_json_document::parse`](../basic_json_document/parse.md) accepts the same inputs and the same options, but
keeps the result as a flat index of the parsed values instead of a tree of `basic_json` values. It is faster and uses keeps the result as a flat index of the parsed values instead of a tree of `basic_json` values. It is faster and uses
less memory when only parts of the document are read, and it also accepts a pointer to a null-terminated wide string, less memory when only parts of the document are read, and it also accepts a pointer to a null-terminated wide string,
which `parse()` does not. See [Zero-copy JSON views](../../features/json_view/index.md). which `parse()` does not. See [Zero-copy JSON views](../../features/json_view.md).
!!! tip "Performance" !!! tip "Performance"
Contiguous inputs (strings, string views, vectors, arrays, pointer ranges) are the fastest to parse. A 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 `#!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. With glibc ahead, so the stream is left exactly where it would be after reading one character at a time. A `#!cpp FILE*` is
and the Apple C library, the characters the `#!cpp FILE` holds in its buffer are scanned in bulk like a stream's; read one character at a time, but the file is locked only once, so other threads that use the same `FILE` object
elsewhere a `#!cpp FILE*` is read one character at a time. Where the C library has unlocked stdio functions, the wait until parsing is done. See [input sources and performance](../../features/parsing/index.md#input-sources-and-performance),
file is locked only once, so other threads that use the same `FILE` object wait until parsing is done, unless [`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) is defined to `1`. See [`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md).
[input sources and performance](../../features/parsing/index.md#input-sources-and-performance) and
[`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md).
## Examples ## Examples
@@ -313,10 +311,6 @@ 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. 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 - 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. (`std::terminate`) when parsing from an `std::istream` with `eofbit` in its exception mask, in version 3.13.0.
- Fixed the position that a [`parse_error.101`](../../home/exceptions.md#jsonexceptionparse_error101) reports for an
unexpected number that is followed by a line feed in version 3.13.0: for the input `1`, line feed, `2`, line feed,
version 3.12.0 reported "line 2, column 0" and version 3.13.0 reports "line 2, column 1"; for `1 2` and a line feed,
the report was "line 1, column 0" and is now "line 1, column 3".
- Parsing from an `std::istream` scans the characters in its stream buffer in bulk 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 ([`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md) restores reading one character at a
time). time).
@@ -15,9 +15,7 @@ the patch. This function applies a JSON patch in place and returns void.
## Exception safety ## Exception safety
No guarantees: if an operation fails, the operations before it stay applied, and a failing `move` operation may already No guarantees, value may be corrupted by an unsuccessful patch operation.
have removed the value at its "from" location. Use [`patch`](patch.md) if the value must be unchanged after a failed
patch.
## Exceptions ## Exceptions
@@ -64,19 +62,8 @@ the JSON value, the complexity can usually be neglected.
## Notes ## Notes
Unlike [`patch`](patch.md), `patch_inplace` applies the operation "in place" and no copy of the JSON value is created. Unlike [`patch`](patch.md), `patch_inplace` applies the operation "in place" and no copy of the JSON value is created.
That makes it faster for large documents by avoiding the copy. That makes it faster for large documents by avoiding the copy. However, the JSON value might be corrupted if the
function throws an exception.
!!! warning "Not atomic"
`patch_inplace` applies the operations one after the other and does not undo them when one fails. After an
exception, the value holds the result of the operations before the failing one, and a failing `move` operation
(a "remove" followed by an "add") may already have removed the value at its "from" location; see the second example
below. [RFC 6902](https://tools.ietf.org/html/rfc6902#section-5) requires that a patch with a failing operation is
not deemed successful, but leaves open what happens to the document.
If the value must stay unchanged when the patch fails, use [`patch`](patch.md), which applies the patch to a copy:
`#!cpp j = j.patch(json_patch);`. Validating the patch beforehand is not enough, as "test" operations and missing
paths are only detected while the patch is applied.
Duplicate member names inside an operation object are resolved by the parser before the patch is applied (the last one Duplicate member names inside an operation object are resolved by the parser before the patch is applied (the last one
is kept, see [`object_t`](object_t.md#behavior)), so `#!json {"op": "add", "op": "remove", "path": "/a"}` is a is kept, see [`object_t`](object_t.md#behavior)), so `#!json {"op": "add", "op": "remove", "path": "/a"}` is a
@@ -27,16 +27,6 @@ void push_back(initializer_list_t init);
`init` is converted into an object element and added using `push_back(const typename object_t::value_type&)`. `init` is converted into an object element and added using `push_back(const typename object_t::value_type&)`.
Otherwise, `init` is converted to a JSON value and added using `push_back(basic_json&&)`. Otherwise, `init` is converted to a JSON value and added using `push_back(basic_json&&)`.
!!! note "Single braced JSON value"
For a call such as `#!cpp arr.push_back({obj})`, where the initializer list contains a single JSON value `obj`,
compilers may disagree unless
[`JSON_BRACE_INIT_COPY_SEMANTICS`](../macros/json_brace_init_copy_semantics.md) is defined to `1`: GCC, for
example, selects this overload and appends a single-element array `[obj]`, whereas Clang selects the
`basic_json` overload and appends a copy of `obj`. With the macro, GCC and Clang both append a copy of `obj`.
To get a portable result without the macro, write `#!cpp arr.push_back(obj)` to append a copy, or
`#!cpp arr.push_back(json::array({obj}))` to append a single-element array.
## Iterator invalidation ## Iterator invalidation
For all cases where an element is added to an **array**, a reallocation can happen, in which case all iterators (including For all cases where an element is added to an **array**, a reallocation can happen, in which case all iterators (including
+3 -4
View File
@@ -124,10 +124,9 @@ consumer `sax` has a super-linear complexity.
A UTF-8 byte order mark is silently ignored. A UTF-8 byte order mark is silently ignored.
When reading from a `#!c FILE*` where the C library has unlocked stdio functions, the file is locked while it is parsed, When reading from a `#!c FILE*`, the file is locked while it is parsed. The lock is recursive, so the SAX handler may
unless [`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md) is defined to `1`. use the same file with stdio functions, but it must not wait for another thread that uses the same `FILE` object; see
The lock is recursive, so the SAX handler may use the same file with stdio functions, but it must not wait for another [`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md).
thread that uses the same `FILE` object.
## Examples ## Examples
@@ -67,7 +67,3 @@ Constant.
## Version history ## Version history
- Added in version 3.12.0. - Added in version 3.12.0.
- Fixed in version 3.13.0: in version 3.12.0, the start position of a string that contains escape sequences (for
example `#!cpp "\n"` or `#!cpp "\u00e4"`) was too large, by the number of bytes the escape sequences add to the
source text. The position is now always that of the opening `"`. The "(bytes a-b)" range in the messages of
[`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) was wrong in the same way.
+3 -5
View File
@@ -60,11 +60,9 @@ String values are stored as pointers in a `basic_json` type. That is, for any ac
When converting a string value from one `basic_json` specialization to another via the When converting a string value from one `basic_json` specialization to another via the
[converting constructor](basic_json.md) (overload 4), the target `string_t` must be directly [converting constructor](basic_json.md) (overload 4), the target `string_t` must be directly
constructible from the source `basic_json`'s `string_t` type. If this requirement is not met, the constructible from the source `basic_json`'s `string_t` type. If this requirement is not met, the
conversion depends on the source string type. If it is a range of characters, the string is converted as an array of conversion does not fail; instead, the string is silently converted as an array of character codes,
character codes, which is incorrect: the converting constructor's [`JSON_ASSERT`](../macros/json_assert.md) fails; with which is incorrect. See [issue #3425](https://github.com/nlohmann/json/issues/3425) for details
its default definition, `assert`, the program aborts unless `NDEBUG` is defined, in which case the array is returned. and an example.
If the source string type is not a range of characters, the conversion does not compile at all. See
[issue #3425](https://github.com/nlohmann/json/issues/3425) for details and an example.
## Examples ## Examples
@@ -77,7 +77,7 @@ compile; see [`parse`](parse.md#notes).
- [`parse`](parse.md) - deserialize from a compatible input - [`parse`](parse.md) - deserialize from a compatible input
- [`BasicJsonType::accept`](../basic_json/accept.md) - the corresponding function of `basic_json` - [`BasicJsonType::accept`](../basic_json/accept.md) - the corresponding function of `basic_json`
- [Zero-copy JSON views](../../features/json_view/differences.md#what-is-the-same) - how parsing a document differs from, and matches, basic_json::parse - [Zero-copy JSON views](../../features/json_view.md#what-is-the-same-as-parse) - how parsing a document differs from, and matches, basic_json::parse
## Version history ## Version history
@@ -52,7 +52,7 @@ Constant.
- [`parse`](parse.md) - deserialize from a compatible input - [`parse`](parse.md) - deserialize from a compatible input
- [`is_discarded`](is_discarded.md) - return whether the last parse failed - [`is_discarded`](is_discarded.md) - return whether the last parse failed
- [Zero-copy JSON views](../../features/json_view/lifetime.md) - who owns the source text and for how long - [Zero-copy JSON views](../../features/json_view.md#ownership-and-lifetime) - who owns the source text and for how long
## Version history ## Version history
@@ -123,7 +123,7 @@ by an erase, not only those at or after the removed element, since the container
- [`root`](root.md) - the view of the root value, the starting point of overload 3 - [`root`](root.md) - the view of the root value, the starting point of overload 3
- [`BasicJsonType::erase`](../basic_json/erase.md) - the corresponding function of `basic_json` - [`BasicJsonType::erase`](../basic_json/erase.md) - the corresponding function of `basic_json`
- [Edits](index.md#edits) - what an edit guarantees, for every overload - [Edits](index.md#edits) - what an edit guarantees, for every overload
- [Zero-copy JSON views](../../features/json_view/editing.md) - what an edit guarantees and costs - [Zero-copy JSON views](../../features/json_view.md#editing-a-document) - what an edit guarantees and costs
## Version history ## Version history
@@ -109,17 +109,16 @@ points apply to every edit:
anything `BasicJsonType` can be constructed from (numbers, strings, `#!cpp bool`, `#!cpp nullptr`, containers, ...). anything `BasicJsonType` can be constructed from (numbers, strings, `#!cpp bool`, `#!cpp nullptr`, containers, ...).
- [`dump()`](../basic_json_view/dump.md) writes an edited document with members in document order, new members at - [`dump()`](../basic_json_view/dump.md) writes an edited document with members in document order, new members at
the end, and, with [`number_format::source`](../basic_json_view/number_format.md), keeps the spelling of every the end, and, with [`number_format::source`](../basic_json_view/number_format.md), keeps the spelling of every
number that was not itself edited — see [Editing a document](../../features/json_view/editing.md) for number that was not itself edited — see [Editing a document](../../features/json_view.md#editing-a-document) for
why this matters. why this matters.
- [`read()`](read.md) discards all edits (so its `input` must not be a string obtained from this document), - [`read()`](read.md) discards all edits, [`shrink_to_fit()`](shrink_to_fit.md) does not move the node index once
[`shrink_to_fit()`](shrink_to_fit.md) does not move the node index once there are edits, and there are edits, and [`memory_usage()`](memory_usage.md) includes the memory edits use.
[`memory_usage()`](memory_usage.md) includes the memory edits use.
[`source_offset()`](../basic_json_view/source_offset.md) of a value introduced by an edit is [`source_offset()`](../basic_json_view/source_offset.md) of a value introduced by an edit is
`#!cpp static_cast<std::size_t>(-1)`, the same value it reports for a decoded string. `#!cpp static_cast<std::size_t>(-1)`, the same value it reports for a decoded string.
## See also ## See also
- [Zero-copy JSON views](../../features/json_view/index.md) - guide to documents and views - [Zero-copy JSON views](../../features/json_view.md) - guide to documents and views
- [`basic_json_view`](../basic_json_view/index.md) - the non-owning handle to a value in a document - [`basic_json_view`](../basic_json_view/index.md) - the non-owning handle to a value in a document
- [`json_document`](../json_document.md) - and [`json_editable_document`](../json_editable_document.md) - the default specializations - [`json_document`](../json_document.md) - and [`json_editable_document`](../json_editable_document.md) - the default specializations
- [`materialize`](../basic_json_view/materialize.md) - build a `basic_json` value from a view - [`materialize`](../basic_json_view/materialize.md) - build a `basic_json` value from a view
@@ -108,7 +108,7 @@ an edit in general.
- [`set`](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers to - [`set`](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers to
- [`BasicJsonType::insert`](../basic_json/insert.md) - the corresponding function of `basic_json` - [`BasicJsonType::insert`](../basic_json/insert.md) - the corresponding function of `basic_json`
- [Edits](index.md#edits) - what an edit guarantees, for every overload - [Edits](index.md#edits) - what an edit guarantees, for every overload
- [Zero-copy JSON views](../../features/json_view/editing.md) - what an edit guarantees and costs - [Zero-copy JSON views](../../features/json_view.md#editing-a-document) - what an edit guarantees and costs
## Version history ## Version history
@@ -43,7 +43,7 @@ When the document is discarded, [`root()`](root.md) returns a discarded view (it
- [`parse`](parse.md) - deserialize from a compatible input - [`parse`](parse.md) - deserialize from a compatible input
- [`basic_json_view::is_discarded`](../basic_json_view/is_discarded.md) - return whether a view is invalid - [`basic_json_view::is_discarded`](../basic_json_view/is_discarded.md) - return whether a view is invalid
- [Zero-copy JSON views](../../features/json_view/differences.md#what-is-the-same) - how a discarded document arises - [Zero-copy JSON views](../../features/json_view.md#what-is-the-same-as-parse) - how a discarded document arises
## Version history ## Version history
@@ -24,7 +24,7 @@ static basic_json_document load(std::vector<std::uint8_t>&& image,
In every overload, the node index is copied into storage the document itself owns — so that it is properly aligned, In every overload, the node index is copied into storage the document itself owns — so that it is properly aligned,
and, for an [editable](index.md#edits) document, can be edited — while the text and the decoded strings stay in and, for an [editable](index.md#edits) document, can be edited — while the text and the decoded strings stay in
`image`. The hash indexes [large objects](../../features/json_view/index.md) use for lookup are rebuilt, exactly as after `image`. The hash indexes [large objects](../../features/json_view.md) use for lookup are rebuilt, exactly as after
parsing. parsing.
## Parameters ## Parameters
@@ -113,12 +113,11 @@ How thoroughly `load()` validates `image` before trusting it.
`full` (the default) `full` (the default)
: Checks everything the parser itself guarantees: structure and bounds; that every string is valid UTF-8 (and, for a : 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 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, and has the type the parser gives it (a float node only token is well-formed and matches the value stored for it. Strings and float tokens may share a range only if the
for a token with a fraction or an exponent, or an integer that does not fit 64 bits). Strings and float tokens may ranges are identical (as nodes that share a value do), and never overlap otherwise. Reading and serializing a
share a range only if the ranges are identical (as nodes that share a value do), and never overlap otherwise. checked image is safe and always produces valid JSON, exactly as for a parsed document. This is the right choice for
Reading and serializing a checked image is safe and always produces valid JSON, exactly as for a parsed document. an image from anything you do not fully control — a file, a cache shared with other processes, a peer on the
This is the right choice for an image from anything you do not fully control — a file, a cache shared with other network.
processes, a peer on the network.
`bounds` `bounds`
: Checks structure and bounds only: that every offset and count in the node index stays inside the image. So : Checks structure and bounds only: that every offset and count in the node index stays inside the image. So
@@ -173,7 +172,7 @@ returned document, and any [view](../basic_json_view/index.md) taken from it, is
- [`save`](save.md) - write the document as an image - [`save`](save.md) - write the document as an image
- [`owns_source`](owns_source.md) - return whether the document holds its own copy of the text - [`owns_source`](owns_source.md) - return whether the document holds its own copy of the text
- [`parse`](parse.md) - deserialize from JSON text instead of an image - [`parse`](parse.md) - deserialize from JSON text instead of an image
- [Images](../../features/json_view/images.md) - why and when to use images - [Images](../../features/json_view.md#images) - why and when to use images
## Version history ## Version history
@@ -44,7 +44,7 @@ to observe the effect of [`shrink_to_fit()`](shrink_to_fit.md).
- [`node_count`](node_count.md) - the number of index entries - [`node_count`](node_count.md) - the number of index entries
- [`shrink_to_fit`](shrink_to_fit.md) - release unused index capacity - [`shrink_to_fit`](shrink_to_fit.md) - release unused index capacity
- [Zero-copy JSON views](../../features/json_view/index.md#the-idea) - the flat node index and its memory - [Zero-copy JSON views](../../features/json_view.md#the-idea) - the flat node index and its memory
## Version history ## Version history
@@ -43,7 +43,7 @@ strings and, for an owned document, the text).
- [`memory_usage`](memory_usage.md) - the number of bytes held by the document - [`memory_usage`](memory_usage.md) - the number of bytes held by the document
- [`shrink_to_fit`](shrink_to_fit.md) - release unused index capacity - [`shrink_to_fit`](shrink_to_fit.md) - release unused index capacity
- [Zero-copy JSON views](../../features/json_view/index.md#the-idea) - the flat node index and its memory - [Zero-copy JSON views](../../features/json_view.md#the-idea) - the flat node index and its memory
## Version history ## Version history
@@ -43,7 +43,7 @@ document (`#!cpp owns_source() == false`) is only valid while the buffer it was
- [`parse`](parse.md) - deserialize from a compatible input - [`parse`](parse.md) - deserialize from a compatible input
- [`parse_copy`](parse_copy.md) - deserialize a copy of a compatible input, always owned - [`parse_copy`](parse_copy.md) - deserialize a copy of a compatible input, always owned
- [`source`](source.md) - the parsed text - [`source`](source.md) - the parsed text
- [Zero-copy JSON views](../../features/json_view/lifetime.md) - who owns the source text and for how long - [Zero-copy JSON views](../../features/json_view.md#ownership-and-lifetime) - who owns the source text and for how long
## Version history ## Version history
@@ -112,7 +112,7 @@ told apart from other class-type iterators, so their range is read into an owned
range (e.g. of a `#!cpp std::list<char>`). range (e.g. of a `#!cpp std::list<char>`).
See [`owns_source`](owns_source.md) to check which happened after a call, and the See [`owns_source`](owns_source.md) to check which happened after a call, and the
[feature page](../../features/json_view/index.md) for the reasoning. [feature page](../../features/json_view.md) for the reasoning.
**Numbers.** As for [`BasicJsonType::parse()`](../basic_json/parse.md), an integer literal too large for the 64-bit **Numbers.** As for [`BasicJsonType::parse()`](../basic_json/parse.md), an integer literal too large for the 64-bit
integer type becomes a floating-point value. integer type becomes a floating-point value.
@@ -74,7 +74,7 @@ compile; see [`parse`](parse.md#notes).
- [`parse`](parse.md) - deserialize from a compatible input, borrowing it where possible - [`parse`](parse.md) - deserialize from a compatible input, borrowing it where possible
- [`owns_source`](owns_source.md) - return whether the document holds its own copy of the text - [`owns_source`](owns_source.md) - return whether the document holds its own copy of the text
- [Zero-copy JSON views](../../features/json_view/lifetime.md) - borrowing or copying the source text - [Zero-copy JSON views](../../features/json_view.md#ownership-and-lifetime) - borrowing or copying the source text
## Version history ## Version history
@@ -96,7 +96,7 @@ Like [`set`](set.md) on a member or an element, `push_back` never moves an exist
- [`root`](root.md) - the view of the root value - [`root`](root.md) - the view of the root value
- [`BasicJsonType::push_back`](../basic_json/push_back.md) - the corresponding function of `basic_json` - [`BasicJsonType::push_back`](../basic_json/push_back.md) - the corresponding function of `basic_json`
- [Edits](index.md#edits) - what an edit guarantees, for every overload - [Edits](index.md#edits) - what an edit guarantees, for every overload
- [Zero-copy JSON views](../../features/json_view/editing.md) - what an edit guarantees and costs - [Zero-copy JSON views](../../features/json_view.md#editing-a-document) - what an edit guarantees and costs
## Version history ## Version history
@@ -46,34 +46,6 @@ Linear in the length of the input.
Every view taken from `#!cpp *this` before the call — including the previous [`root()`](root.md) — is invalidated, Every view taken from `#!cpp *this` before the call — including the previous [`root()`](root.md) — is invalidated,
whether or not the new parse succeeds; take fresh views from [`root()`](root.md) afterward. whether or not the new parse succeeds; take fresh views from [`root()`](root.md) afterward.
!!! warning "`input` must not point into the document itself"
`read()` releases the document's previous text, its decoded strings, and (for an editable document) its edits
*before* it parses `input`. An `input` that is, or points into, any of them violates a precondition: it may seem to
work, parse empty or garbled text, be reported by a sanitizer, or read freed memory (undefined behavior).
This applies to every `string_view` obtained from the document whose characters live in memory that `read()`
releases:
- [`source()`](source.md) of a document that owns its text;
- [`get_string()`](../basic_json_view/get_string.md) (also as `get<string_view_t>()` or a `string_view` member of a
decoded struct) of a string with escapes, of a string of a document that owns its text, and of an edited string;
- [`number_token()`](../basic_json_view/number_token.md) of a number of a document that owns its text, and of a
number written by an edit;
- the key of an object member (`key()`) if it has escapes, was written by an edit, or the document owns its text.
It does not apply to a text that the caller owns and the document borrows, nor to the strings, keys, and tokens that
are read from such a text unchanged, nor to the decoded strings of a borrowed [image](load.md), which live in the
caller's image: `read()` never touches them. To parse JSON that a document holds in a string of its own (for
example, JSON embedded in a string value), copy the string first, for example with
`#!cpp std::string inner(doc.root()["payload"].get_string()); doc.read(inner);`.
A debug build (one without `NDEBUG`) checks this with `assert()`: an `input` in the document's text, decoded
strings, or image, or in the most recent buffer of strings written by edits, ends the program. (Strings written
by earlier edits are not covered.) A release build does not check, to keep the cost of reusing a document at a
minimum. The check uses `assert()` directly, not [`JSON_ASSERT`](../macros/json_assert.md), which `json.hpp`
undefines at its end.
`input` is borrowed or owned by the same rules as [`parse()`](parse.md#notes); a document can borrow on one call and `input` is borrowed or owned by the same rules as [`parse()`](parse.md#notes); a document can borrow on one call and
own on the next, since ownership is decided freshly each time. An input that is copied (see the table in own on the next, since ownership is decided freshly each time. An input that is copied (see the table in
[`parse()`](parse.md#notes)) is written into the document's previous owned copy, reusing its memory; a moved-in [`parse()`](parse.md#notes)) is written into the document's previous owned copy, reusing its memory; a moved-in
@@ -109,7 +81,7 @@ compile; see [`parse`](parse.md#notes).
- [`parse`](parse.md) - deserialize from a compatible input - [`parse`](parse.md) - deserialize from a compatible input
- [`root`](root.md) - the view of the root value - [`root`](root.md) - the view of the root value
- [`load`](load.md) - read a document from an image instead of parsing JSON text - [`load`](load.md) - read a document from an image instead of parsing JSON text
- [Zero-copy JSON views](../../features/json_view/lifetime.md) - reusing a document and what it invalidates - [Zero-copy JSON views](../../features/json_view.md#ownership-and-lifetime) - reusing a document and what it invalidates
## Version history ## Version history
@@ -40,7 +40,7 @@ auto v = doc.root();
returned view is valid under the same conditions as any other view of the document — see returned view is valid under the same conditions as any other view of the document — see
[Object inspection](../basic_json_view/index.md) — in particular, it is invalidated by the next [Object inspection](../basic_json_view/index.md) — in particular, it is invalidated by the next
[`read()`](read.md) or [`shrink_to_fit()`](shrink_to_fit.md) on this document. A view can dangle, like a [`read()`](read.md) or [`shrink_to_fit()`](shrink_to_fit.md) on this document. A view can dangle, like a
`#!cpp std::string_view`; see [Ownership and lifetime](../../features/json_view/lifetime.md). `#!cpp std::string_view`; see [Ownership and lifetime](../../features/json_view.md#ownership-and-lifetime).
## Examples ## Examples
@@ -91,7 +91,7 @@ big-endian reader could not interpret correctly.
- [`load`](load.md) - read an image written by `save()` - [`load`](load.md) - read an image written by `save()`
- [`owns_source`](owns_source.md) - return whether the document holds its own copy of the text - [`owns_source`](owns_source.md) - return whether the document holds its own copy of the text
- [`basic_json_view::dump`](../basic_json_view/dump.md) - serialize the document to JSON text instead of an image - [`basic_json_view::dump`](../basic_json_view/dump.md) - serialize the document to JSON text instead of an image
- [Images](../../features/json_view/images.md) - why and when to use images - [Images](../../features/json_view.md#images) - why and when to use images
## Version history ## Version history
@@ -195,7 +195,7 @@ one-node scalar.
- [`basic_json_view::dump`](../basic_json_view/dump.md) - serialize the document, keeping an untouched number's - [`basic_json_view::dump`](../basic_json_view/dump.md) - serialize the document, keeping an untouched number's
spelling with `#!cpp number_format::source` spelling with `#!cpp number_format::source`
- [Edits](index.md#edits) - what an edit guarantees, for every overload - [Edits](index.md#edits) - what an edit guarantees, for every overload
- [Editing a document](../../features/json_view/editing.md) - why editable documents keep the source - [Editing a document](../../features/json_view.md#editing-a-document) - why editable documents keep the source
text's order and number spelling text's order and number spelling
## Version history ## Version history
@@ -56,7 +56,7 @@ possible would be an internal optimization only, not a guarantee to rely on.
- [`node_count`](node_count.md) - the number of index entries - [`node_count`](node_count.md) - the number of index entries
- [`memory_usage`](memory_usage.md) - the number of bytes held by the document - [`memory_usage`](memory_usage.md) - the number of bytes held by the document
- [`root`](root.md) - the view of the root value - [`root`](root.md) - the view of the root value
- [Zero-copy JSON views](../../features/json_view/lifetime.md) - what releasing memory invalidates - [Zero-copy JSON views](../../features/json_view.md#ownership-and-lifetime) - what releasing memory invalidates
## Version history ## Version history
@@ -24,9 +24,6 @@ Constant.
For a borrowed document, `source()` points directly into the caller's buffer, so it is only valid while that buffer For a borrowed document, `source()` points directly into the caller's buffer, so it is only valid while that buffer
is; see [`owns_source`](owns_source.md). is; see [`owns_source`](owns_source.md).
The text of a document that owns it must not be passed to [`read()`](read.md) of the same document: `read()` releases
an owned text before it parses its input. Copy it first. (A borrowed text belongs to the caller and is not affected.)
## Examples ## Examples
??? example ??? example
@@ -45,7 +42,7 @@ an owned text before it parses its input. Copy it first. (A borrowed text belong
- [`owns_source`](owns_source.md) - return whether the document holds its own copy of the text - [`owns_source`](owns_source.md) - return whether the document holds its own copy of the text
- [`source_offset`](../basic_json_view/source_offset.md) - byte offset of a value in the source text - [`source_offset`](../basic_json_view/source_offset.md) - byte offset of a value in the source text
- [Zero-copy JSON views](../../features/json_view/lifetime.md) - who owns the source text and for how long - [Zero-copy JSON views](../../features/json_view.md#ownership-and-lifetime) - who owns the source text and for how long
## Version history ## Version history
+1 -1
View File
@@ -92,7 +92,7 @@ Pointer path of the value within the document, and with
If the source text repeats a key, this resolves to the *first* member with it, not to the last one that If the source text repeats a key, this resolves to the *first* member with it, not to the last one that
[`materialize()`](materialize.md) and `parse()` keep. See the [Notes on duplicate keys](operator[].md#notes) of [`materialize()`](materialize.md) and `parse()` keep. See the [Notes on duplicate keys](operator[].md#notes) of
`operator[]` and [Duplicate keys](../../features/json_view/differences.md#duplicate-keys) for the reasons and for how to get `operator[]` and [Duplicate keys](../../features/json_view.md#duplicate-keys) for the reasons and for how to get
the last value. the last value.
Unlike [`operator[]`](operator[].md), which returns a [discarded](is_discarded.md) view for a missing key or an Unlike [`operator[]`](operator[].md), which returns a [discarded](is_discarded.md) view for a missing key or an
@@ -58,7 +58,7 @@ placeholder for "no value yet" and later be assigned a real view.
- [`is_discarded`](is_discarded.md) - return whether the view is invalid - [`is_discarded`](is_discarded.md) - return whether the view is invalid
- [`root`](../basic_json_document/root.md) - the view of a document's root value - [`root`](../basic_json_document/root.md) - the view of a document's root value
- [`view_mode`](../view_mode.md) - whether a document and its views can be edited - [`view_mode`](../view_mode.md) - whether a document and its views can be edited
- [Zero-copy JSON views](../../features/json_view/lifetime.md) - how long a view stays valid - [Zero-copy JSON views](../../features/json_view.md#ownership-and-lifetime) - how long a view stays valid
## Version history ## Version history
@@ -47,7 +47,7 @@ No-throw guarantee: this function never throws exceptions.
If the source text repeats a key, this resolves to the *first* member with it, not to the last one that If the source text repeats a key, this resolves to the *first* member with it, not to the last one that
[`materialize()`](materialize.md) and `parse()` keep. See the [Notes on duplicate keys](operator[].md#notes) of [`materialize()`](materialize.md) and `parse()` keep. See the [Notes on duplicate keys](operator[].md#notes) of
`operator[]` and [Duplicate keys](../../features/json_view/differences.md#duplicate-keys) for the reasons and for how to get `operator[]` and [Duplicate keys](../../features/json_view.md#duplicate-keys) for the reasons and for how to get
the last value. the last value.
Overload 1 always returns `#!cpp false` when the value is not an object — including a [discarded](is_discarded.md) Overload 1 always returns `#!cpp false` when the value is not an object — including a [discarded](is_discarded.md)
+4 -7
View File
@@ -48,11 +48,8 @@ Strong exception safety: if an exception is thrown, there are no changes to the
May throw `#!cpp std::bad_alloc` if allocating the output string fails. Unlike May throw `#!cpp std::bad_alloc` if allocating the output string fails. Unlike
[`BasicJsonType::dump`](../basic_json/dump.md), there is no `error_handler` parameter and no [`BasicJsonType::dump`](../basic_json/dump.md), there is no `error_handler` parameter and no
[`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316): the parser validated the text the view [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316): the view only ever holds text the parser
holds as UTF-8, so there is nothing to replace or ignore. Only a document loaded with already validated as UTF-8, so there is nothing to replace or ignore.
[`image_check::bounds` or `image_check::none`](../basic_json_document/load.md#image_check) can still throw it: these do
not check the strings, so `dump()` writes such a string as it is, which can be invalid UTF-8 or invalid JSON, and
`dump()` with `ensure_ascii` set to `#!cpp true` throws `type_error.316` for invalid UTF-8.
## Complexity ## Complexity
@@ -73,7 +70,7 @@ except that `#!cpp -0` is written as `#!cpp 0`, the way [`BasicJsonType::parse()
`#!cpp number_format::source` copies every number exactly as written in the source text instead, with no exception `#!cpp number_format::source` copies every number exactly as written in the source text instead, with no exception
for `#!cpp -0` — `#!cpp 1.50`, `#!cpp 1E2`, `#!cpp -0.0`, `#!cpp -0`, or all digits of an integer literal with more for `#!cpp -0` — `#!cpp 1.50`, `#!cpp 1E2`, `#!cpp -0.0`, `#!cpp -0`, or all digits of an integer literal with more
digits than any number type holds (such a literal is itself classified as a float, see digits than any number type holds (such a literal is itself classified as a float, see
[What is different](../../features/json_view/differences.md)) — something `BasicJsonType` cannot do, since [What is different](../../features/json_view.md#what-is-different)) — something `BasicJsonType` cannot do, since
parsing already reduces every number to its parsed value. parsing already reduces every number to its parsed value.
## Examples ## Examples
@@ -101,7 +98,7 @@ parsing already reduces every number to its parsed value.
- [`operator<<`](operator_ltlt.md) - serialize this value to a stream - [`operator<<`](operator_ltlt.md) - serialize this value to a stream
- [`materialize`](materialize.md) - build a `BasicJsonType` value, e.g. to use `BasicJsonType::dump`'s `error_handler` - [`materialize`](materialize.md) - build a `BasicJsonType` value, e.g. to use `BasicJsonType::dump`'s `error_handler`
- [`BasicJsonType::dump`](../basic_json/dump.md) - the corresponding function of `basic_json` - [`BasicJsonType::dump`](../basic_json/dump.md) - the corresponding function of `basic_json`
- [Zero-copy JSON views](../../features/json_view/reading.md#writing-a-view-back) - writing a view back without building a tree - [Zero-copy JSON views](../../features/json_view.md#writing-a-view-back) - writing a view back without building a tree
## Version history ## Version history
+1 -1
View File
@@ -37,7 +37,7 @@ constant time on average.
If the source text repeats a key, this resolves to the *first* member with it, not to the last one that If the source text repeats a key, this resolves to the *first* member with it, not to the last one that
[`materialize()`](materialize.md) and `parse()` keep. See the [Notes on duplicate keys](operator[].md#notes) of [`materialize()`](materialize.md) and `parse()` keep. See the [Notes on duplicate keys](operator[].md#notes) of
`operator[]` and [Duplicate keys](../../features/json_view/differences.md#duplicate-keys) for the reasons and for how to get `operator[]` and [Duplicate keys](../../features/json_view.md#duplicate-keys) for the reasons and for how to get
the last value. the last value.
Unlike [`BasicJsonType::find`](../basic_json/find.md), which always returns `#!cpp end()` for a non-object type, this Unlike [`BasicJsonType::find`](../basic_json/find.md), which always returns `#!cpp end()` for a non-object type, this
+3 -3
View File
@@ -39,14 +39,14 @@ as [`BasicJsonType::parse()`](../basic_json/parse.md) does), as well as the type
accept views, e.g. with [`is_json_view`](../is_json_view.md). A `from_json()` that also accepts types that are no JSON accept views, e.g. with [`is_json_view`](../is_json_view.md). A `from_json()` that also accepts types that are no JSON
values at all, such as the unconstrained `#!cpp template<typename BasicJsonType> void from_json(const BasicJsonType&, values at all, such as the unconstrained `#!cpp template<typename BasicJsonType> void from_json(const BasicJsonType&,
T&)` of [arbitrary type conversions](../../features/arbitrary_types.md), is not called with a view: it may use T&)` of [arbitrary type conversions](../../features/arbitrary_types.md), is not called with a view: it may use
`BasicJsonType` functions a view does not have. See [Writing generic code](../../features/json_view/generic_code.md). `BasicJsonType` functions a view does not have. See [Writing generic code](../../features/json_view.md#writing-generic-code).
!!! warning "Duplicate keys" !!! warning "Duplicate keys"
Such a `from_json()` looks members up in the view, where a repeated key finds the **first** member, while Such a `from_json()` looks members up in the view, where a repeated key finds the **first** member, while
`#!cpp materialize().get<T>()` sees the **last** one, as [`BasicJsonType::parse()`](../basic_json/parse.md) `#!cpp materialize().get<T>()` sees the **last** one, as [`BasicJsonType::parse()`](../basic_json/parse.md)
keeps it: for `#!cpp {"x":1,"x":2}`, `#!cpp get<point>()` reads `#!cpp x == 1`. See keeps it: for `#!cpp {"x":1,"x":2}`, `#!cpp get<point>()` reads `#!cpp x == 1`. See
[Duplicate keys](../../features/json_view/differences.md#duplicate-keys). [Duplicate keys](../../features/json_view.md#duplicate-keys).
Every other `T` — user types whose `from_json()` is written for `BasicJsonType` only, types without a default Every other `T` — user types whose `from_json()` is written for `BasicJsonType` only, types without a default
constructor, `#!cpp std::tuple`s holding references, ... — is converted by `#!cpp materialize().get<T>()`: the subtree is built into a real `BasicJsonType` constructor, `#!cpp std::tuple`s holding references, ... — is converted by `#!cpp materialize().get<T>()`: the subtree is built into a real `BasicJsonType`
@@ -152,7 +152,7 @@ instead: its path is relative to the root of the view's subtree, because `materi
- [`number_token`](number_token.md) - a number's token text, without a copy - [`number_token`](number_token.md) - a number's token text, without a copy
- [`materialize`](materialize.md) - build the `BasicJsonType` value of this subtree - [`materialize`](materialize.md) - build the `BasicJsonType` value of this subtree
- [`BasicJsonType::get`](../basic_json/get.md) - the corresponding function of `basic_json` - [`BasicJsonType::get`](../basic_json/get.md) - the corresponding function of `basic_json`
- [Zero-copy JSON views](../../features/json_view/reading.md#getting-values-out-without-copying) - which conversions avoid building a basic_json value - [Zero-copy JSON views](../../features/json_view.md#getting-values-out-without-copying) - which conversions avoid building a basic_json value
## Version history ## Version history
@@ -46,10 +46,6 @@ The returned [`string_view_t`](index.md#member-types) is valid exactly as long a
source text, which for a borrowed document must remain valid **and unmodified** for as long as the document exists, source text, which for a borrowed document must remain valid **and unmodified** for as long as the document exists,
since floating-point values and unescaped strings are read from the source lazily. since floating-point values and unescaped strings are read from the source lazily.
A string with escapes, a string of a document that owns its text, and an edited string must not be passed to
[`read()`](../basic_json_document/read.md) of the document it came from: `read()` releases them before it parses its
input. Copy the string first. (A string read unchanged from a borrowed text is not affected.)
## Examples ## Examples
??? example ??? example
@@ -74,7 +70,7 @@ input. Copy the string first. (A string read unchanged from a borrowed text is n
- [`get`](get.md) - convert the value to a given type (`#!cpp get<string_view_t>()` is equivalent to this function) - [`get`](get.md) - convert the value to a given type (`#!cpp get<string_view_t>()` is equivalent to this function)
- [`number_token`](number_token.md) - a number's token text, without a copy - [`number_token`](number_token.md) - a number's token text, without a copy
- [`BasicJsonType::get_ref`](../basic_json/get_ref.md) - the closest counterpart of `basic_json` - [`BasicJsonType::get_ref`](../basic_json/get_ref.md) - the closest counterpart of `basic_json`
- [Zero-copy JSON views](../../features/json_view/reading.md#getting-values-out-without-copying) - borrowing strings instead of copying them - [Zero-copy JSON views](../../features/json_view.md#getting-values-out-without-copying) - borrowing strings instead of copying them
## Version history ## Version history
@@ -75,7 +75,7 @@ them with those of a default-constructed `T`.
- [`get`](get.md) - convert the value to a given type - [`get`](get.md) - convert the value to a given type
- [`BasicJsonType::get_to`](../basic_json/get_to.md) - the corresponding function of `basic_json` - [`BasicJsonType::get_to`](../basic_json/get_to.md) - the corresponding function of `basic_json`
- [Zero-copy JSON views](../../features/json_view/reading.md#getting-values-out-without-copying) - which conversions avoid building a basic_json value - [Zero-copy JSON views](../../features/json_view.md#getting-values-out-without-copying) - which conversions avoid building a basic_json value
## Version history ## Version history
@@ -147,7 +147,7 @@ still refers to it — including ones taken before the change — reads the new
## See also ## See also
- [Zero-copy JSON views](../../features/json_view/index.md) - guide to documents and views - [Zero-copy JSON views](../../features/json_view.md) - guide to documents and views
- [`basic_json_document`](../basic_json_document/index.md) - the document that owns the parsed data - [`basic_json_document`](../basic_json_document/index.md) - the document that owns the parsed data
- [`json_view`](../json_view.md) - and [`json_editable_view`](../json_editable_view.md) - the default specializations - [`json_view`](../json_view.md) - and [`json_editable_view`](../json_editable_view.md) - the default specializations
- [`materialize`](materialize.md) - build a `basic_json` value from a view - [`materialize`](materialize.md) - build a `basic_json` value from a view
@@ -54,7 +54,7 @@ A `basic_json_view` is not convertible to `#!cpp bool`: such a conversion would
- [`(constructor)`](basic_json_view.md) - the default constructor creates a discarded view - [`(constructor)`](basic_json_view.md) - the default constructor creates a discarded view
- [`basic_json_document::is_discarded`](../basic_json_document/is_discarded.md) - return whether the last parse failed - [`basic_json_document::is_discarded`](../basic_json_document/is_discarded.md) - return whether the last parse failed
- [`BasicJsonType::is_discarded`](../basic_json/is_discarded.md) - the corresponding function of `basic_json` - [`BasicJsonType::is_discarded`](../basic_json/is_discarded.md) - the corresponding function of `basic_json`
- [Zero-copy JSON views](../../features/json_view/differences.md) - how views differ from basic_json - [Zero-copy JSON views](../../features/json_view.md#what-is-different) - how views differ from basic_json
## Version history ## Version history
@@ -78,7 +78,7 @@ never caches the result.
- [`root`](../basic_json_document/root.md) - the view of a document's root value - [`root`](../basic_json_document/root.md) - the view of a document's root value
- [`BasicJsonType::parse`](../basic_json/parse.md) - build a `BasicJsonType` value directly from a JSON text - [`BasicJsonType::parse`](../basic_json/parse.md) - build a `BasicJsonType` value directly from a JSON text
- [`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md) - source positions on parsed values - [`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md) - source positions on parsed values
- [Zero-copy JSON views](../../features/json_view/reading.md#getting-values-out-without-copying) - when to build a basic_json value from a view - [Zero-copy JSON views](../../features/json_view.md#getting-values-out-without-copying) - when to build a basic_json value from a view
## Version history ## Version history
@@ -45,7 +45,7 @@ source
- [`number_token`](number_token.md) - get a single number's token text without dumping the whole value - [`number_token`](number_token.md) - get a single number's token text without dumping the whole value
- [`BasicJsonType::error_handler_t`](../basic_json/error_handler_t.md) - the analogous enumeration for - [`BasicJsonType::error_handler_t`](../basic_json/error_handler_t.md) - the analogous enumeration for
`BasicJsonType::dump`'s decoding-error behavior `BasicJsonType::dump`'s decoding-error behavior
- [Zero-copy JSON views](../../features/json_view/reading.md#writing-a-view-back) - writing numbers as they appeared in the source - [Zero-copy JSON views](../../features/json_view.md#writing-a-view-back) - writing numbers as they appeared in the source
## Version history ## Version history
@@ -38,14 +38,9 @@ by the grammar; trailing zeros in the fraction; the case and sign of the exponen
useful precisely where that form must survive — a price or an identifier that must be reproduced exactly, or a useful precisely where that form must survive — a price or an identifier that must be reproduced exactly, or a
number too large for any of `BasicJsonType`'s number types to hold without loss. number too large for any of `BasicJsonType`'s number types to hold without loss.
The returned [`string_view_t`](index.md#member-types) points into the document's The returned [`string_view_t`](index.md#member-types) always points into the document's
[`source()`](../basic_json_document/source.md) text or, for a number written by an [`source()`](../basic_json_document/source.md) text — numbers are never decoded into the document's separate string
[edit](../basic_json_document/index.md#edits), into storage owned by the document (the token of an edited `NaN` is buffer — and is valid exactly as long as that text is, see the [validity rules](index.md) of `basic_json_view`.
`nan`). It is valid exactly as long as that text or storage is, see the [validity rules](index.md) of
`basic_json_view`. Numbers are never decoded into the document's separate string buffer.
For the same reason, the token must not be passed to [`read()`](../basic_json_document/read.md) of the document it came
from if that document owns its text or the number was written by an edit: `read()` releases both before it parses.
## Examples ## Examples
@@ -73,7 +68,7 @@ from if that document owns its text or the number was written by an edit: `read(
- [`BasicJsonType::number_integer_t`](../basic_json/number_integer_t.md), - [`BasicJsonType::number_integer_t`](../basic_json/number_integer_t.md),
[`number_unsigned_t`](../basic_json/number_unsigned_t.md), [`number_float_t`](../basic_json/number_float_t.md) - the [`number_unsigned_t`](../basic_json/number_unsigned_t.md), [`number_float_t`](../basic_json/number_float_t.md) - the
number types `#!cpp get<T>()` and `materialize()` convert into number types `#!cpp get<T>()` and `materialize()` convert into
- [Zero-copy JSON views](../../features/json_view/reading.md#getting-values-out-without-copying) - reading a number exactly as written - [Zero-copy JSON views](../../features/json_view.md#getting-values-out-without-copying) - reading a number exactly as written
## Version history ## Version history
@@ -120,7 +120,7 @@ document.
[`materialize()`](materialize.md) or iterate the members with [`items()`](items.md) and keep the last match. [`materialize()`](materialize.md) or iterate the members with [`items()`](items.md) and keep the last match.
The key hash index of a larger object (128 members or more) leads to the first member of a key as well. The key hash index of a larger object (128 members or more) leads to the first member of a key as well.
[`begin()`](begin.md)/[`end()`](end.md) and [`items()`](items.md) iterate over *all* members, including [`begin()`](begin.md)/[`end()`](end.md) and [`items()`](items.md) iterate over *all* members, including
duplicates, in document order. See [Duplicate keys](../../features/json_view/differences.md#duplicate-keys) and duplicates, in document order. See [Duplicate keys](../../features/json_view.md#duplicate-keys) and
[`size()`](size.md#notes). [`size()`](size.md#notes).
!!! info "JSON pointer resolution" !!! info "JSON pointer resolution"
@@ -19,7 +19,7 @@ Neither overload builds a `BasicJsonType` value for a view to do the comparison
compare by value across their types (`#!cpp 1 == 1.0`), and an object compares by its members, with duplicate keys compare by value across their types (`#!cpp 1 == 1.0`), and an object compares by its members, with duplicate keys
resolved exactly as `parse()` resolves them — the last value, at the position of the first occurrence of the key. resolved exactly as `parse()` resolves them — the last value, at the position of the first occurrence of the key.
This is not what [`operator[]`](operator[].md) and the other lookups return for a duplicate key: they find the *first* This is not what [`operator[]`](operator[].md) and the other lookups return for a duplicate key: they find the *first*
member (see [Duplicate keys](../../features/json_view/differences.md#duplicate-keys)). member (see [Duplicate keys](../../features/json_view.md#duplicate-keys)).
## Parameters ## Parameters
@@ -57,9 +57,7 @@ compared. Two arrays of different [`size()`](size.md) are rejected without visit
Only a single number, boolean, or `#!cpp null` value is ever materialized into a `BasicJsonType`, to reuse its Only a single number, boolean, or `#!cpp null` value is ever materialized into a `BasicJsonType`, to reuse its
`operator==` — for numbers, so that values written differently in the source text but equal in value (e.g. an `operator==` — for numbers, so that values written differently in the source text but equal in value (e.g. an
integer and a floating-point literal) still compare equal, following the same rules `BasicJsonType` does for special integer and a floating-point literal) still compare equal, following the same rules `BasicJsonType` does for special
values such as `#!cpp NaN`: a `#!cpp NaN` that an [edit](../basic_json_document/set.md) wrote is not equal to itself, so values such as `#!cpp NaN`. Constructing one of these scalars never allocates. Strings are compared directly, without
a view of it is not equal to itself either, nor is a view of an array or object that contains one, as for
`BasicJsonType`. Constructing one of these scalars never allocates. Strings are compared directly, without
allocating, either from the source text on both sides or, for overload 2, against `BasicJsonType`'s own string. allocating, either from the source text on both sides or, for overload 2, against `BasicJsonType`'s own string.
Arrays and objects are never materialized at all; only their elements or members are visited, one pair at a time. Arrays and objects are never materialized at all; only their elements or members are visited, one pair at a time.
@@ -68,7 +68,7 @@ Linear, as [`dump`](dump.md#complexity).
- [`dump`](dump.md) - serialize to a JSON-formatted string - [`dump`](dump.md) - serialize to a JSON-formatted string
- [`operator<<(std::ostream&)`](../operator_ltlt.md) - the corresponding operator for `basic_json` - [`operator<<(std::ostream&)`](../operator_ltlt.md) - the corresponding operator for `basic_json`
- [`JSON_NO_IO`](../macros/json_no_io.md) - switch off functions relying on certain C++ I/O headers - [`JSON_NO_IO`](../macros/json_no_io.md) - switch off functions relying on certain C++ I/O headers
- [Zero-copy JSON views](../../features/json_view/reading.md#writing-a-view-back) - writing a view back without building a tree - [Zero-copy JSON views](../../features/json_view.md#writing-a-view-back) - writing a view back without building a tree
## Version history ## Version history
@@ -49,7 +49,7 @@ string, whose token length is not the same as its decoded [`size()`](size.md).
- [`source`](../basic_json_document/source.md) - the parsed text - [`source`](../basic_json_document/source.md) - the parsed text
- [`is_string`](is_string.md) - return whether the value is a string - [`is_string`](is_string.md) - return whether the value is a string
- [Zero-copy JSON views](../../features/json_view/images.md) - images and the source text - [Zero-copy JSON views](../../features/json_view.md#images) - images and the source text
## Version history ## Version history
@@ -84,7 +84,7 @@ Pointer path of the value within the document, and with
If the source text repeats a key, this resolves to the *first* member with it, not to the last one that If the source text repeats a key, this resolves to the *first* member with it, not to the last one that
[`materialize()`](materialize.md) and `parse()` keep. See the [Notes on duplicate keys](operator[].md#notes) of [`materialize()`](materialize.md) and `parse()` keep. See the [Notes on duplicate keys](operator[].md#notes) of
`operator[]` and [Duplicate keys](../../features/json_view/differences.md#duplicate-keys) for the reasons and for how to get `operator[]` and [Duplicate keys](../../features/json_view.md#duplicate-keys) for the reasons and for how to get
the last value. the last value.
!!! info "Differences to `at` and `operator[]`" !!! info "Differences to `at` and `operator[]`"
+1 -1
View File
@@ -49,7 +49,7 @@ view class.
- [basic_json_view](basic_json_view/index.md) - a handle to one value of a document - [basic_json_view](basic_json_view/index.md) - a handle to one value of a document
- [get](basic_json_view/get.md) - which conversions read the view directly - [get](basic_json_view/get.md) - which conversions read the view directly
- [view_mode](view_mode.md) - read-only or editable - [view_mode](view_mode.md) - read-only or editable
- [Writing generic code](../features/json_view/generic_code.md) - functions and `from_json()` for views - [Writing generic code](../features/json_view.md#writing-generic-code) - functions and `from_json()` for views
## Version history ## Version history
+1 -1
View File
@@ -29,7 +29,7 @@ specialization.
- [`json_view`](json_view.md) - a view of a value of a `json_document` - [`json_view`](json_view.md) - a view of a value of a `json_document`
- [`ordered_json_document`](ordered_json_document.md) - the corresponding document for `ordered_json` - [`ordered_json_document`](ordered_json_document.md) - the corresponding document for `ordered_json`
- [Zero-copy JSON views](../features/json_view/index.md) - how to parse, inspect and edit a document without building a tree - [Zero-copy JSON views](../features/json_view.md) - how to parse, inspect and edit a document without building a tree
## Version history ## Version history
@@ -10,7 +10,7 @@ This type is an **editable** [`basic_json_document`](basic_json_document/index.m
[`json`](json.md) specialization: in addition to everything [`json_document`](json_document.md) offers, [`json`](json.md) specialization: in addition to everything [`json_document`](json_document.md) offers,
[`set`](basic_json_document/set.md) and [`push_back`](basic_json_document/push_back.md) change values after [`set`](basic_json_document/set.md) and [`push_back`](basic_json_document/push_back.md) change values after
parsing, without ever rewriting the source text — see [Edits](basic_json_document/index.md#edits) and parsing, without ever rewriting the source text — see [Edits](basic_json_document/index.md#edits) and
[Editing a document](../features/json_view/editing.md). [Editing a document](../features/json_view.md#editing-a-document).
## Examples ## Examples
+1 -1
View File
@@ -35,7 +35,7 @@ still referring to it seeing the change, see [Edits](basic_json_document/index.m
- [`json_view`](json_view.md) - the corresponding read-only view - [`json_view`](json_view.md) - the corresponding read-only view
- [`ordered_json_editable_view`](ordered_json_editable_view.md) - the corresponding view for - [`ordered_json_editable_view`](ordered_json_editable_view.md) - the corresponding view for
`ordered_json_editable_document` `ordered_json_editable_document`
- [Zero-copy JSON views](../features/json_view/editing.md) - editing a document in place and writing it back - [Zero-copy JSON views](../features/json_view.md#editing-a-document) - editing a document in place and writing it back
## Version history ## Version history
+1 -1
View File
@@ -28,7 +28,7 @@ This type is a [`basic_json_view`](basic_json_view/index.md) of a value of a [`j
- [`json_document`](json_document.md) - the document type this view refers into - [`json_document`](json_document.md) - the document type this view refers into
- [`ordered_json_view`](ordered_json_view.md) - the corresponding view for `ordered_json_document` - [`ordered_json_view`](ordered_json_view.md) - the corresponding view for `ordered_json_document`
- [Zero-copy JSON views](../features/json_view/index.md) - how to parse, inspect and edit a document without building a tree - [Zero-copy JSON views](../features/json_view.md) - how to parse, inspect and edit a document without building a tree
## Version history ## Version history
-2
View File
@@ -40,8 +40,6 @@ header. See also the [macro overview page](../../features/macros.md).
- [**JSON_NO_IO**](json_no_io.md) - switch off functions relying on certain C++ I/O headers - [**JSON_NO_IO**](json_no_io.md) - switch off functions relying on certain C++ I/O headers
- [**JSON_NO_SIMD**](json_no_simd.md) - use only portable code instead of vector instructions (SSE2, SSSE3, NEON) - [**JSON_NO_SIMD**](json_no_simd.md) - use only portable code instead of vector instructions (SSE2, SSSE3, NEON)
- [**JSON_NO_THREAD_LOCAL**](json_no_thread_local.md) - switch off the use of `thread_local` storage - [**JSON_NO_THREAD_LOCAL**](json_no_thread_local.md) - switch off the use of `thread_local` storage
- [**JSON_RECURSION_DEPTH_LIMIT**](json_recursion_depth_limit.md) - set how many nesting levels the operations on a value
recurse into on the call stack (default 128)
- [**JSON_SKIP_UNSUPPORTED_COMPILER_CHECK**](json_skip_unsupported_compiler_check.md) - do not warn about unsupported compilers - [**JSON_SKIP_UNSUPPORTED_COMPILER_CHECK**](json_skip_unsupported_compiler_check.md) - do not warn about unsupported compilers
- [**JSON_USE_GLOBAL_UDLS**](json_use_global_udls.md) - place user-defined string literals (UDLs) into the global namespace - [**JSON_USE_GLOBAL_UDLS**](json_use_global_udls.md) - place user-defined string literals (UDLs) into the global namespace
- [**JSON_USE_SIMDUTF**](json_use_simdutf.md) - use the simdutf library to accelerate UTF-8 validation - [**JSON_USE_SIMDUTF**](json_use_simdutf.md) - use the simdutf library to accelerate UTF-8 validation
@@ -27,13 +27,9 @@ The default value is `0` (disabled — existing behavior is preserved).
json j{obj}; json j{obj};
``` ```
creates a single-element **array** `[{"key":"value"}]` instead of a copy of `obj`. For this constructor, the creates a single-element **array** `[{"key":"value"}]` instead of a copy of `obj`. This behavior is
behavior was compiler-dependent for older compilers (GCC wrapped, Clang did not), but starting from Clang 20, both compiler-dependent for older compilers (GCC wrapped, Clang did not), but starting from Clang 20, both compilers
compilers behave the same way. behave the same way.
The calls `#!cpp arr.push_back({obj})` and `#!cpp arr += {obj}` are still compiler-dependent without the macro,
even with Clang 20 and later: GCC converts `{obj}` to a single-element array and appends that array, whereas Clang
appends a copy of `obj`. With the macro defined to `1`, both compilers append a copy of `obj`.
Enabling this macro opts into copy/move semantics for this case Enabling this macro opts into copy/move semantics for this case
(see [#5074](https://github.com/nlohmann/json/issues/5074)). (see [#5074](https://github.com/nlohmann/json/issues/5074)).
@@ -34,9 +34,6 @@ or quotes.
Note that enabling this macro increases the size of every JSON value by two `std::size_t` fields and adds slight runtime Note that enabling this macro increases the size of every JSON value by two `std::size_t` fields and adds slight runtime
overhead to parsing, copying JSON value objects, and the generation of error messages for exceptions. It also causes overhead to parsing, copying JSON value objects, and the generation of error messages for exceptions. It also causes
these values to be reported in those error messages. these values to be reported in those error messages.
In addition, `parse()`, `accept()`, and `sax_parse()` no longer use the
[faster path for input in one block of memory](../../features/parsing/index.md#input-sources-and-performance), so
parsing a string or a buffer is slower than without the macro.
If [`JSON_DIAGNOSTICS`](json_diagnostics.md) is also set, the message contains the path and the byte range, such as If [`JSON_DIAGNOSTICS`](json_diagnostics.md) is also set, the message contains the path and the byte range, such as
`(/1) (bytes 4-8)`. An exception about the root value has no path and only the range, such as `(bytes 0-4)`. `(/1) (bytes 4-8)`. An exception about the root value has no path and only the range, such as `(bytes 0-4)`.
@@ -125,5 +122,3 @@ When the macro is not defined, the library will define it to its default value.
## Version history ## Version history
- Added in version 3.12.0. - Added in version 3.12.0.
- Fixed in version 3.13.0: in version 3.12.0, [`start_pos()`](../basic_json/start_pos.md) of a string that contains
escape sequences was too large; it is now the position of the opening `"`.
@@ -48,8 +48,8 @@ The default value is `0`: streams are scanned in bulk.
!!! note "Performance" !!! note "Performance"
Parsing from a `std::ifstream` or `std::istringstream` is typically 1.5 to 2 times as fast as before, and reading 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 then takes about many small values from one stream with `operator>>` 1.4 to 4 times as fast. Parsing from a stream is then within
1.15 to 1.45 times as long as first reading the whole file into a `std::string` and parsing that. 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 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. character from there) offers nothing to scan in bulk, so it is read one character at a time as before.
@@ -5,9 +5,7 @@
``` ```
When defined to `1`, parsing from a `#!cpp FILE*` reads every character with `std::fgetc`, as in version 3.12.0 and 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. This also turns off the earlier, instead of locking the file once and reading it with the unlocked stdio functions.
scan of the `FILE`'s buffer in bulk (see below), which [`JSON_DISABLE_STREAM_BULK_SCAN`](json_disable_stream_bulk_scan.md)
does not affect.
It does not change any result: values, exceptions, and the position of the file after parsing are the same either way. 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). Only the speed and the locking of the file differ (see the notes on locking below).
@@ -39,17 +37,9 @@ The default value is `0`: the file is locked once and read with the unlocked std
| Microsoft (MSVC, clang-cl) | `_lock_file`, `_fgetc_nolock`, `_unlock_file` | | Microsoft (MSVC, clang-cl) | `_lock_file`, `_fgetc_nolock`, `_unlock_file` |
| others (e.g., musl, MinGW, newlib) | `std::fgetc`, as before | | others (e.g., musl, MinGW, newlib) | `std::fgetc`, as before |
With glibc and the Apple C library, the parser also scans the characters that the `FILE` already holds in its 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
buffer in bulk, as it scans the get area of a stream (see glibc, whose locking is cheaper. The binary formats ([`from_cbor`](../basic_json/from_cbor.md),
[`JSON_DISABLE_STREAM_BULK_SCAN`](json_disable_stream_bulk_scan.md)): it reads the same fields of the `FILE` that [`from_msgpack`](../basic_json/from_msgpack.md), ...) read from a `FILE*` the same way.
the C library's own `getc_unlocked` reads, and it consumes exactly the characters that `getc_unlocked` would have
returned, so the file is left where it was left before.
Locking the file once 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. Scanning the buffer in bulk makes `parse()` another 1.7 to 2.6
times as fast (and `accept()` 2.9 to 4.4 times), about as fast as parsing from a `std::ifstream`. 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" !!! note "Locking"
+1 -1
View File
@@ -80,7 +80,7 @@ By default, `#!cpp JSON_NO_SIMD` is not defined, and vector instructions are use
- [Parsing: input sources and performance](../../features/parsing/index.md#input-sources-and-performance) - how input - [Parsing: input sources and performance](../../features/parsing/index.md#input-sources-and-performance) - how input
sources affect parsing performance sources affect parsing performance
- [Serialization](../../features/serialization.md) - pretty-printing, UTF-8 handling, and number output - [Serialization](../../features/serialization.md) - pretty-printing, UTF-8 handling, and number output
- [Zero-copy JSON views](../../features/json_view/index.md) - the zero-copy view, whose parser the macro also affects - [Zero-copy JSON views](../../features/json_view.md) - the zero-copy view, whose parser the macro also affects
## Version history ## Version history
@@ -45,7 +45,6 @@ Copying and comparing fall back to working without the call stack there, as they
## See also ## See also
- [`JSON_RECURSION_DEPTH_LIMIT`](json_recursion_depth_limit.md) - set how many nesting levels the operations recurse into
- [FAQ: Thread safety](../../home/faq.md#thread-safety) - thread-safety guarantees of the library - [FAQ: Thread safety](../../home/faq.md#thread-safety) - thread-safety guarantees of the library
- [Supported Macros](../../features/macros.md) - guide to all supported macros - [Supported Macros](../../features/macros.md) - guide to all supported macros
@@ -1,307 +0,0 @@
# JSON_RECURSION_DEPTH_LIMIT
```cpp
#define JSON_RECURSION_DEPTH_LIMIT /* value */
```
This macro sets how many nesting levels the operations that walk a value recurse into on the call stack. Beyond that,
they continue with an explicit stack on the heap. The value is an integer constant from `0` to `254`; the default is
`128`.
The operations are copying a value, comparing two values, serializing with [`dump`](../basic_json/dump.md) or
[`operator<<`](../operator_ltlt.md), hashing with `std::hash`, [`merge_patch`](../basic_json/merge_patch.md),
[`update`](../basic_json/update.md) with `merge_objects`, [`diff`](../basic_json/diff.md),
[`merge_diff`](../basic_json/merge_diff.md), converting a value to another specialization of `basic_json`, destroying a
value, and the binary writers [`to_cbor`](../basic_json/to_cbor.md),
[`to_msgpack`](../basic_json/to_msgpack.md), [`to_ubjson`](../basic_json/to_ubjson.md),
[`to_bjdata`](../basic_json/to_bjdata.md), and [`to_bon8`](../basic_json/to_bon8.md). They share this one limit; none
has
a limit of its own. Recursing is the fastest way to walk a value, but a value nested deeply enough would exhaust the
call
stack, so the library recurses only as far as the limit and finishes the levels below with an explicit stack. This is
what makes all of them safe for untrusted input
(see [Nesting depth](../../features/parsing/untrusted_input.md#nesting-depth)). Parsing, the binary readers,
[`flatten`](../basic_json/flatten.md), [`unflatten`](../basic_json/unflatten.md), and
[`to_bson`](../basic_json/to_bson.md) always use an explicit stack and do not depend on the macro. The lockstep
comparison of two [`json_view`](../basic_json_view/index.md) documents has a fixed bound of its own, 48 levels,
and does not depend on it either.
The call stack that these operations need grows with the limit: roughly *a few kilobytes plus a cost per level times the
limit*, where the cost per level is up to about 2.3 KiB in an unoptimized and up to about 0.5 KiB in an optimized build
(see [Stack needed](#stack-needed)). The default of `128` levels is tuned for threads with ordinary stacks of a few
hundred kilobytes or more. Set a lower limit if your threads have small stacks (RTOS tasks, fibers, threads of the musl
C
library, which has a default stack of 128 KiB), or a higher limit to trade stack for speed on deeply nested values.
The macro changes only how much stack is used and how fast the operations are. It never changes a result: every
operation returns the same value for every setting of the limit, for values nested less deeply than the limit as well as
for values nested more deeply.
## Default definition
The default value is `128`.
```cpp
#define JSON_RECURSION_DEPTH_LIMIT 128
```
When the macro is not defined, the library defines it to its default value.
## Notes
!!! note "Allowed values"
The value must be an integer constant expression from `0` to `254`; any other value (a negative number, a number
above `254`, a floating-point number such as `254.0`, or `true` or `false`) is rejected at compile time with an
error message that names the macro. A character of any character type (`'a'`, `L'a'`, `u8'a'`, ...) is rejected,
too, although it is an integer.
- `0` is allowed, and means that every operation uses its explicit stack from the first level on and no operation
recurses over the nesting of a value at all. That needs a constant amount of call stack (at most 16 KiB in the
measurements below, for a value nested 20,000 levels deep) and is the setting for tiny stacks, at the price of
speed (see [Speed](#speed)).
- `254` is the largest allowed value. Copying a value and comparing two values (with `<=>`, or with the operators on
objects and arrays of a custom type) cannot pass the depth down as an argument, because the signatures of the
copy constructor and the operators are fixed. They count the levels they have descended into in a variable of type
`#!cpp std::uint8_t` that exists once per thread (see [`JSON_NO_THREAD_LOCAL`](json_no_thread_local.md)). Only
the levels that are descended into are counted, so the count never exceeds the limit, not even when user code (a
copy constructor of a custom base class, say) copies a value while a copy is going on. A byte holds `255` at
most, and the limit stays below that, so that the count cannot wrap around. (More levels would hardly be
useful: `254` levels need up to 576 KiB of stack in an unoptimized build already, twice as much as the
default.)
### Stack needed
The tables show the smallest stack that an operation needs, in KiB, at several limits, on a value that is nested
more deeply than the limit (limit + 10 levels). Each cell shows the result for Clang (Apple clang 21) and for
GCC 16, separated by a slash; both measured on macOS with arm64, compiling in C++20 mode. The operations run in a
thread whose stack has the size given, and are not given any stack that they do not need: the value is built, and
the result destroyed, outside of that thread. Stacks can only be set in steps of 16 KiB (the page size), so `16`
means "16 KiB or less". A row stands for all operations listed; the table shows the largest value among them.
Unoptimized (`-O0`):
| Operation | limit 16 | limit 32 | limit 64 | limit 128 | limit 254 |
|---|---:|---:|---:|---:|---:|
| `dump()` and `dump(indent)`, `operator<<` | 48 / 32 | 80 / 64 | 144 / 128 | 288 / 256 | 576 / 512 |
| copy construction and assignment | 32 / 16 | 48 / 32 | 112 / 80 | 224 / 144 | 432 / 304 |
| `==` | 16 / 16 | 16 / 16 | 16 / 16 | 48 / 32 | 96 / 48 |
| `<=>` (C++20) | 16 / 16 | 16 / 16 | 32 / 32 | 64 / 64 | 144 / 128 |
| `std::hash` | 16 / 16 | 16 / 16 | 32 / 32 | 80 / 64 | 160 / 128 |
| `merge_patch`, `update(j, true)`, `patch` | 32 / 16 | 48 / 32 | 112 / 80 | 224 / 144 | 432 / 304 |
| `diff` | 16 / 16 | 16 / 16 | 32 / 32 | 64 / 48 | 144 / 96 |
| `merge_diff` | 16 / 16 | 48 / 32 | 80 / 48 | 176 / 112 | 352 / 224 |
| `to_cbor`, `to_msgpack` | 16 / 16 | 32 / 16 | 64 / 32 | 112 / 80 | 224 / 160 |
| `to_ubjson`, `to_bjdata` | 16 / 16 | 16 / 16 | 48 / 32 | 96 / 64 | 176 / 112 |
| `to_bon8` | 16 / 16 | 16 / 16 | 16 / 16 | 32 / 16 | 64 / 48 |
| conversion to another `basic_json` type | 32 / 16 | 64 / 32 | 112 / 80 | 224 / 144 | 448 / 304 |
| destruction | 16 / 16 | 16 / 16 | 16 / 16 | 16 / 16 | 32 / 32 |
Optimized (`-O2`):
| Operation | limit 16 | limit 32 | limit 64 | limit 128 | limit 254 |
|---|---:|---:|---:|---:|---:|
| `dump()` and `dump(indent)`, `operator<<` | 16 / 16 | 16 / 16 | 16 / 16 | 16 / 16 | 32 / 32 |
| copy construction and assignment | 16 / 16 | 16 / 16 | 16 / 16 | 32 / 32 | 64 / 48 |
| `==` | 16 / 16 | 16 / 16 | 16 / 16 | 16 / 16 | 16 / 16 |
| `<=>` (C++20) | 16 / 16 | 16 / 16 | 16 / 16 | 16 / 16 | 48 / 16 |
| `std::hash` | 16 / 16 | 16 / 16 | 16 / 16 | 32 / 48 | 80 / 80 |
| `merge_patch`, `update(j, true)`, `patch` | 16 / 16 | 16 / 16 | 16 / 16 | 32 / 32 | 64 / 48 |
| `diff` | 16 / 16 | 16 / 16 | 16 / 32 | 48 / 48 | 96 / 112 |
| `merge_diff` | 16 / 16 | 16 / 16 | 16 / 16 | 48 / 32 | 96 / 64 |
| `to_cbor`, `to_msgpack` | 16 / 16 | 16 / 16 | 16 / 16 | 16 / 16 | 16 / 16 |
| `to_ubjson`, `to_bjdata` | 16 / 16 | 16 / 16 | 16 / 16 | 32 / 32 | 64 / 64 |
| `to_bon8` | 16 / 16 | 16 / 16 | 16 / 16 | 16 / 32 | 32 / 64 |
| conversion to another `basic_json` type | 16 / 16 | 16 / 16 | 16 / 16 | 32 / 48 | 64 / 96 |
| destruction | 16 / 16 | 16 / 16 | 16 / 16 | 16 / 16 | 16 / 16 |
With a limit of `0`, every operation in the tables ran in a 16 KiB stack at `-O0` (Clang and GCC), on a value nested
20,000 levels deep. The operations that do not depend on the macro (`flatten`, `unflatten`, `to_bson`) needed
16 KiB or less at every limit.
The rule of thumb is
> stack needed ≈ a few KiB + cost per level × limit
with a cost per level of up to 2.3 KiB (`dump` at `-O0` with Clang; 2.1 KiB with GCC), 1.7 KiB for copying and merging
(1.3 KiB with GCC), and 0.1 to 0.5 KiB for most other operations at `-O0`; and 0.5 KiB or less at `-O2`. The numbers
come from the difference between the limits `128` and `254` in the tables, so they are rough: other compilers,
other targets (the frames of x86-64 code are about as large), other standard libraries, `JSON_DIAGNOSTICS`, and
sanitizers change them. Measure with your own tool chain (see the example below) rather than relying on the tables.
The stack that your own code and the operating system need comes on top of these numbers.
Which limit to choose, for the stack that you can spare for the library (the largest limit of those measured
for which the slowest operation needs at most that much):
| Stack for the library | optimized (`-O2`) | unoptimized (`-O0`) |
|---|---:|---:|
| 32 KiB | 64 | 0 |
| 64 KiB | 128 | 16 |
| 128 KiB (the default stack of threads on musl) | 254 | 32 |
| 256 KiB | 254 | 64 |
| 512 KiB | 254 | 128 |
| 1 MiB or more | 254 | 254 |
### Speed
Operations are faster the more of a value they handle with plain recursion. The levels below the limit are handled with
an explicit stack, which has to be kept on the heap and costs more per level. The macro therefore trades speed against
stack.
The table shows the time of copying a value (including destroying the copy), of `==` on two equal values, of `dump`, and
of `std::hash` for several limits, relative to the default of `128` (`1.00` means the same time; more is slower). It was
measured with Clang 21 at `-O2` in C++17 mode on macOS with arm64, as the best of seven runs of each setting (two
rounds, best of both). The documents are ordinary JSON files that are nested 7 (`canada.json`), 8
(`citm_catalog.json`), 10 (`twitter.json`), and 2 levels deep (`jeopardy.json`); the other values are one array or object
with one member per level, nested 1,000 and 100,000 levels deep. The absolute time at the limit `128` is given in the
third column. Differences of up to about 0.1 are noise: a different limit changes the layout of the compiled code, and
timings of the same binary vary by about as much. The slow columns (limits 0 and 1) vary more: repeating `std::hash` on
`canada.json` gave 1.27 to 1.30 for limit 0 and 1.4 to 1.9 for limit 1, so read the cells of those two columns as
accurate to about 0.3.
| Value | Operation | limit 128 (absolute) | limit 0 | limit 1 | limit 16 | limit 254 |
|---|---|---:|---:|---:|---:|---:|
| `canada.json` (2.1 MB) | copy | 3.5 ms | 1.80 | 1.80 | 0.99 | 1.00 |
| `canada.json` (2.1 MB) | `==` | 350.5 µs | 2.36 | 2.38 | 1.00 | 0.99 |
| `canada.json` (2.1 MB) | `dump` | 2.4 ms | 1.11 | 1.11 | 1.00 | 1.00 |
| `canada.json` (2.1 MB) | `std::hash` | 920.2 µs | 1.33 | 1.59 | 1.00 | 1.00 |
| `citm_catalog.json` (1.7 MB) | copy | 1.8 ms | 1.38 | 1.36 | 1.00 | 0.99 |
| `citm_catalog.json` (1.7 MB) | `==` | 275.5 µs | 1.31 | 1.31 | 0.99 | 1.00 |
| `citm_catalog.json` (1.7 MB) | `dump` | 314.6 µs | 1.24 | 1.23 | 1.00 | 1.00 |
| `citm_catalog.json` (1.7 MB) | `std::hash` | 309.1 µs | 1.77 | 1.42 | 1.06 | 1.05 |
| `twitter.json` (0.6 MB) | copy | 865.7 µs | 1.45 | 1.47 | 1.01 | 1.00 |
| `twitter.json` (0.6 MB) | `==` | 135.8 µs | 1.26 | 1.23 | 1.00 | 1.00 |
| `twitter.json` (0.6 MB) | `dump` | 224.6 µs | 1.12 | 1.12 | 1.01 | 1.00 |
| `twitter.json` (0.6 MB) | `std::hash` | 132.9 µs | 1.28 | 1.27 | 1.03 | 1.04 |
| `jeopardy.json` (53 MB) | copy | 111.1 ms | 1.22 | 1.25 | 1.00 | 1.00 |
| `jeopardy.json` (53 MB) | `==` | 23.5 ms | 1.29 | 1.53 | 1.07 | 1.00 |
| `jeopardy.json` (53 MB) | `dump` | 33.2 ms | 1.14 | 1.34 | 1.03 | 1.01 |
| `jeopardy.json` (53 MB) | `std::hash` | 19.9 ms | 1.17 | 1.52 | 1.05 | 1.00 |
| arrays, 1,000 levels | copy | 69.9 µs | 0.95 | 0.98 | 0.92 | 0.99 |
| arrays, 1,000 levels | `==` | 10.4 µs | 1.02 | 1.01 | 0.96 | 1.00 |
| arrays, 1,000 levels | `dump` | 9.6 µs | 0.97 | 0.96 | 0.97 | 1.06 |
| arrays, 1,000 levels | `std::hash` | 16.9 µs | 1.00 | 1.01 | 1.01 | 0.98 |
| objects, 1,000 levels | copy | 77.1 µs | 0.98 | 0.97 | 0.97 | 1.03 |
| objects, 1,000 levels | `==` | 12.0 µs | 0.96 | 0.95 | 0.95 | 1.07 |
| objects, 1,000 levels | `dump` | 12.6 µs | 0.97 | 0.95 | 0.98 | 1.01 |
| objects, 1,000 levels | `std::hash` | 17.3 µs | 0.99 | 1.01 | 0.98 | 1.00 |
| arrays, 100,000 levels | copy | 6.4 ms | 1.00 | 1.00 | 1.00 | 1.00 |
| arrays, 100,000 levels | `==` | 1.1 ms | 1.01 | 1.03 | 1.00 | 1.06 |
| arrays, 100,000 levels | `dump` | 917.9 µs | 1.01 | 1.01 | 1.02 | 1.01 |
| arrays, 100,000 levels | `std::hash` | 1.7 ms | 1.04 | 1.05 | 0.99 | 0.99 |
| objects, 100,000 levels | copy | 7.5 ms | 0.99 | 1.02 | 1.01 | 0.99 |
| objects, 100,000 levels | `==` | 1.3 ms | 1.02 | 1.09 | 1.08 | 0.96 |
| objects, 100,000 levels | `dump` | 1.2 ms | 1.06 | 0.99 | 1.01 | 0.99 |
| objects, 100,000 levels | `std::hash` | 1.8 ms | 1.00 | 1.00 | 1.00 | 1.00 |
The results are as follows.
- A limit of `16` or more does not change the speed of ordinary documents (differences are within noise), because they
are not nested more deeply than that anyway. A document nested more deeply than the limit is walked partly with the
explicit stack.
- A limit of `0` or `1` makes the operations on ordinary documents 1.1 to 2.4 times as slow, because even their first
levels are handled with the explicit stack. The slowdown is largest for `==` on a document of many small containers
(`canada.json`: 2.4 times) and for copying (up to 1.8 times).
- For values that are nested far more deeply than any limit (1,000 and 100,000 levels deep), the limit makes no
measurable difference: almost all of the levels are handled with the explicit stack for every setting.
Raising the limit gains nothing for them, and lowering it costs nothing.
!!! note "Other macros"
- With [`JSON_NO_THREAD_LOCAL`](json_no_thread_local.md) defined (or for Clang targeting MinGW, where the library
defines it by itself), copying and comparing never descend, so for them the limit does not matter. The other
operations still recurse as many levels as the limit says. The range of the limit is the same.
- The macro is not part of the [ABI tag](../../features/namespace.md), as `JSON_NO_THREAD_LOCAL` is not, and it is
not undefined at the end of `json.hpp`.
!!! warning "Use the same value in every translation unit"
All translation units of a program that include the library must define the same value. Otherwise, the program
violates the One Definition Rule: the function `nlohmann::detail::recursion_depth_limit()` and all the functions
that use it are defined differently in different translation units. Which limit a call uses then depends on which
functions the compiler inlined (an inlined copy uses the value of its own translation unit) and which out-of-line
copy of each remaining function the linker kept, which is not specified. A function compiled with one value can
call a function compiled with another, so a single operation can mix both limits.
Mixing values cannot corrupt the byte per thread that counts the levels of copying and comparing: each limit
is at most `254`, and all of them stop counting at their own limit, so the count never exceeds `254`, whichever
translation unit's definition runs. The counter exists once per thread and `basic_json` specialization, and is
shared by all translation units. Nor can mixing values change any result, as no result depends on the limit. What
changes is how much stack is used and how fast the operations are. Nevertheless, avoid it: the program has undefined
behavior as far as the C++ standard is concerned.
## Examples
??? example "Example: lower the limit"
The example nests an array 5,000 levels deep. With the limit set to 16, the library recurses over the first 16
levels
and over the rest uses an explicit stack. The results are those of the default limit.
```cpp
--8<-- "examples/json_recursion_depth_limit.cpp"
```
Output:
```
--8<-- "examples/json_recursion_depth_limit.output"
```
??? example "Example: find out how much stack an operation needs"
The program runs `dump()` on a value nested `depth` levels deep in a thread with a stack of `kib` KiB. Compile it
with the options and the limit that you use, e.g. `-DJSON_RECURSION_DEPTH_LIMIT=64`, run it with `depth` set to the
limit plus 10 and decreasing values of `kib` (the stack size must be a multiple of the page size, often 4 or 16
KiB),
and note the smallest stack with which it still finishes. That is how the tables above were measured.
```cpp
#include <cstdlib>
#include <iostream>
#include <string>
#include <utility>
#include <pthread.h>
#include <nlohmann/json.hpp>
static nlohmann::json value;
static void* run(void*)
{
std::cout << "dump() ok, " << value.dump().size() << " bytes\n";
return nullptr;
}
int main(int argc, char** argv)
{
const int depth = std::atoi(argv[1]);
const std::size_t kib = static_cast<std::size_t>(std::atoi(argv[2]));
// built on the main thread, without recursion
value = 1;
for (int i = 0; i < depth; ++i)
{
nlohmann::json outer = nlohmann::json::array();
outer.push_back(std::move(value));
value = std::move(outer);
}
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setstacksize(&attr, kib * 1024);
pthread_t thread;
pthread_create(&thread, &attr, run, nullptr);
pthread_join(thread, nullptr);
}
```
## See also
- [Nesting depth](../../features/parsing/untrusted_input.md#nesting-depth) - how the library handles deeply nested
values
- [`JSON_NO_THREAD_LOCAL`](json_no_thread_local.md) - switch off the use of `thread_local` storage
- [Supported Macros](../../features/macros.md) - guide to all supported macros
## Version history
- Added in version 3.13.0.
@@ -93,7 +93,7 @@ The default value is `0` (disabled, the behavior of version 3.12.0 and earlier i
## See also ## See also
- [Binary formats](../../features/binary_formats/index.md) - overview of the supported binary formats - [Binary formats](../../features/binary_formats/index.md) - overview of the supported binary formats
- [`from_cbor`](../basic_json/from_cbor.md) - not affected by the macro; pass `error_handler` to validate CBOR strings - [`from_cbor`](../basic_json/from_cbor.md) - also affected when parsing CBOR strings
- [`to_cbor`](../basic_json/to_cbor.md) - create a CBOR serialization of a JSON value - [`to_cbor`](../basic_json/to_cbor.md) - create a CBOR serialization of a JSON value
- [`to_ubjson`](../basic_json/to_ubjson.md) - create a UBJSON serialization of a JSON value - [`to_ubjson`](../basic_json/to_ubjson.md) - create a UBJSON serialization of a JSON value
- [`to_bjdata`](../basic_json/to_bjdata.md) - create a BJData serialization of a JSON value - [`to_bjdata`](../basic_json/to_bjdata.md) - create a BJData serialization of a JSON value
@@ -32,7 +32,7 @@ of object keys, instead of sorting them like [`json_document`](json_document.md)
- [`ordered_json_view`](ordered_json_view.md) - a view of a value of an `ordered_json_document` - [`ordered_json_view`](ordered_json_view.md) - a view of a value of an `ordered_json_document`
- [`json_document`](json_document.md) - the corresponding document for the default `json` specialization - [`json_document`](json_document.md) - the corresponding document for the default `json` specialization
- [Object Order](../features/object_order.md) - preserving the insertion order of object keys - [Object Order](../features/object_order.md) - preserving the insertion order of object keys
- [Zero-copy JSON views](../features/json_view/index.md) - how to parse, inspect and edit a document without building a tree - [Zero-copy JSON views](../features/json_view.md) - how to parse, inspect and edit a document without building a tree
## Version history ## Version history
@@ -41,7 +41,7 @@ members [`set`](basic_json_document/set.md) added — instead of sorting them li
specialization specialization
- [Object Order](../features/object_order.md) - preserving the insertion order of object keys - [Object Order](../features/object_order.md) - preserving the insertion order of object keys
- [Edits](basic_json_document/index.md#edits) - what an edit guarantees - [Edits](basic_json_document/index.md#edits) - what an edit guarantees
- [Zero-copy JSON views](../features/json_view/editing.md) - editing a document in place and writing it back - [Zero-copy JSON views](../features/json_view.md#editing-a-document) - editing a document in place and writing it back
## Version history ## Version history
@@ -34,7 +34,7 @@ This type is a [`basic_json_view`](basic_json_view/index.md) of a value of an
- [`ordered_json_editable_document`](ordered_json_editable_document.md) - the document type this view refers into - [`ordered_json_editable_document`](ordered_json_editable_document.md) - the document type this view refers into
- [`ordered_json_view`](ordered_json_view.md) - the corresponding read-only view - [`ordered_json_view`](ordered_json_view.md) - the corresponding read-only view
- [`json_editable_view`](json_editable_view.md) - the corresponding view for `json_editable_document` - [`json_editable_view`](json_editable_view.md) - the corresponding view for `json_editable_document`
- [Zero-copy JSON views](../features/json_view/editing.md) - editing a document in place and writing it back - [Zero-copy JSON views](../features/json_view.md#editing-a-document) - editing a document in place and writing it back
## Version history ## Version history
+1 -1
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@@ -29,7 +29,7 @@ This type is a [`basic_json_view`](basic_json_view/index.md) of a value of an
- [`ordered_json_document`](ordered_json_document.md) - the document type this view refers into - [`ordered_json_document`](ordered_json_document.md) - the document type this view refers into
- [`json_view`](json_view.md) - the corresponding view for `json_document` - [`json_view`](json_view.md) - the corresponding view for `json_document`
- [Zero-copy JSON views](../features/json_view/index.md) - how to parse, inspect and edit a document without building a tree - [Zero-copy JSON views](../features/json_view.md) - how to parse, inspect and edit a document without building a tree
## Version history ## Version history
+1 -1
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@@ -82,7 +82,7 @@ nor a [`json_editable_view`](json_editable_view.md). Views of the two modes comp
- [basic_json_view](basic_json_view/index.md) - a handle to one value of a document - [basic_json_view](basic_json_view/index.md) - a handle to one value of a document
- [json_editable_document](json_editable_document.md) - an editable document of `json` - [json_editable_document](json_editable_document.md) - an editable document of `json`
- [(constructor)](basic_json_view/basic_json_view.md) - the conversion from a read-only to an editable view - [(constructor)](basic_json_view/basic_json_view.md) - the conversion from a read-only to an editable view
- [Writing generic code](../features/json_view/generic_code.md) - functions that accept views - [Writing generic code](../features/json_view.md#writing-generic-code) - functions that accept views
## Version history ## Version history
+2 -5
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@@ -53,15 +53,12 @@ flowchart LR
only as bytes are actually read, arrays reserve at most a fixed number of elements up front, and sizes that no only as bytes are actually read, arrays reserve at most a fixed number of elements up front, and sizes that no
container can hold are rejected. container can hold are rejected.
- **Memory is owned by values.** Each `basic_json` value owns its content, and there is no manual memory management in - **Memory is owned by values.** Each `basic_json` value owns its content, and there is no manual memory management in
user code. The destructor recurses only over a bounded number of nesting levels and then continues without the call user code. The destructor does not recurse, so destroying a deeply nested value does not exhaust the stack.
stack, so destroying a deeply nested value does not exhaust the stack.
- **Bounded recursion.** The JSON parser and the binary readers keep their state in explicit stacks instead of - **Bounded recursion.** The JSON parser and the binary readers keep their state in explicit stacks instead of
recursing per nesting level. Operations that walk a value, such as [`dump`](../api/basic_json/dump.md), copying, recursing per nesting level. Operations that walk a value, such as [`dump`](../api/basic_json/dump.md), copying,
comparison, hashing, [`merge_patch`](../api/basic_json/merge_patch.md), [`diff`](../api/basic_json/diff.md), comparison, hashing, [`merge_patch`](../api/basic_json/merge_patch.md), [`diff`](../api/basic_json/diff.md),
[`flatten`](../api/basic_json/flatten.md), and the binary writers, recurse only up to a fixed depth and continue with [`flatten`](../api/basic_json/flatten.md), and the binary writers, recurse only up to a fixed depth and continue with
an explicit stack below it. The depth is 128 levels by default and can be changed with an explicit stack below it. Applications that process untrusted input can limit its nesting depth with a
[`JSON_RECURSION_DEPTH_LIMIT`](../api/macros/json_recursion_depth_limit.md), for example to run on a small stack.
Applications that process untrusted input can limit its nesting depth with a
[parser callback](../features/parsing/parser_callbacks.md). [parser callback](../features/parsing/parser_callbacks.md).
- **Invariants are checked.** The class invariant (for instance, that the pointer for the stored type is never null) is - **Invariants are checked.** The class invariant (for instance, that the pointer for the stored type is never null) is
checked with runtime assertions throughout the test suite. checked with runtime assertions throughout the test suite.
+1 -25
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@@ -759,14 +759,9 @@ body:has(.nj-hero) .md-content {
} }
} }
/* blog posts: author and date right below the title */
.md-typeset .nj-byline { margin: -.8rem 0 1.6rem; font-size: .75rem; color: var(--md-default-fg-color--light); }
.md-typeset .nj-byline a { color: inherit; }
.md-typeset .nj-byline a:hover { color: var(--md-accent-fg-color); }
/* figure captions: "Figure N." in bold, close to the figure, set in from the text column; figures and tables are /* figure captions: "Figure N." in bold, close to the figure, set in from the text column; figures and tables are
numbered per page, each with its own counter */ numbered per page, each with its own counter */
.md-content__inner { counter-reset: nj-figure nj-table nj-listing; } .md-content__inner { counter-reset: nj-figure nj-table; }
.md-typeset :is(.nj-caption, .nj-charts-caption) { .md-typeset :is(.nj-caption, .nj-charts-caption) {
max-width: none; max-width: none;
margin: .3rem 2rem 1.5rem; margin: .3rem 2rem 1.5rem;
@@ -787,25 +782,6 @@ body:has(.nj-hero) .md-content {
.md-typeset :is(.nj-caption, .nj-charts-caption) { margin-inline: 1rem; } .md-typeset :is(.nj-caption, .nj-charts-caption) { margin-inline: 1rem; }
} }
/* code captions: "Listing N." in bold, directly below the code block, in the figure caption style */
.md-typeset .nj-code-caption {
max-width: none;
margin: -.4rem 2rem 1.5rem;
font-size: .75rem;
line-height: 1.5;
text-align: left;
color: var(--md-default-fg-color--light);
}
.md-typeset .nj-code-caption::before {
counter-increment: nj-listing;
content: "Listing " counter(nj-listing) ". ";
font-weight: 700;
color: var(--md-default-fg-color);
}
@media screen and (max-width: 44.9375em) {
.md-typeset .nj-code-caption { margin-inline: 1rem; }
}
/* table captions: "Table N." in bold, directly below the table, in the figure caption style */ /* table captions: "Table N." in bold, directly below the table, in the figure caption style */
.md-typeset .nj-table-caption { .md-typeset .nj-table-caption {
max-width: none; max-width: none;
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