Split the Visual Studio 2017 AppVeyor jobs in two

The VS 2017 jobs hit AppVeyor's 60-minute limit per job while still compiling the tests (77 of about 108 test targets after 58 minutes). They pass /std:c++17 for everything anyway, so build only the C++17 variant of each test (JSON_TestStandards=17), and split the unit test files across two jobs each with the new JSON_TestShard=<index>/<count> option, which keeps every <count>-th test file starting at <index>. The extra variants of single test files are built in shard 0 only. CMAKE_OPTIONS is no longer quoted in appveyor.yml, so that it can hold more than one option. Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Skip deleted-function detection checks on MSVC 2015
2026-10-05 23:44:38 +07:00 · 2026-10-05 17:44:51 +02:00 · 2026-10-05 14:58:12 +02:00 · 2026-10-05 13:49:28 +02:00 · 2026-10-05 13:29:32 +02:00 · 2026-10-05 13:00:09 +02:00
16 changed files with 221 additions and 62 deletions
@@ -16,6 +16,9 @@ only_commits:

 environment:
  matrix:
+    # The Visual Studio 2017 jobs compile everything with /std:c++17, so they
+    # only build the C++17 variant of each test, split into two jobs each to
+    # stay below AppVeyor's 60-minute limit per job.
    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
      configuration: Debug
      platform: x86
@@ -34,7 +37,13 @@ environment:
      configuration: Release
      platform: x86
      CXX_FLAGS: "/permissive- /std:c++17 /utf-8 /W4 /WX"
-      CMAKE_OPTIONS: ""
+      CMAKE_OPTIONS: "-DJSON_TestStandards=17 -DJSON_TestShard=0/2"
+      GENERATOR: Visual Studio 15 2017
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+      configuration: Release
+      platform: x86
+      CXX_FLAGS: "/permissive- /std:c++17 /utf-8 /W4 /WX"
+      CMAKE_OPTIONS: "-DJSON_TestStandards=17 -DJSON_TestShard=1/2"
      GENERATOR: Visual Studio 15 2017

    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
@@ -55,7 +64,13 @@ environment:
      configuration: Release
      platform: x64
      CXX_FLAGS: "/permissive- /std:c++17 /Zc:__cplusplus /utf-8 /W4 /WX"
-      CMAKE_OPTIONS: ""
+      CMAKE_OPTIONS: "-DJSON_TestStandards=17 -DJSON_TestShard=0/2"
+      GENERATOR: Visual Studio 15 2017
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+      configuration: Release
+      platform: x64
+      CXX_FLAGS: "/permissive- /std:c++17 /Zc:__cplusplus /utf-8 /W4 /WX"
+      CMAKE_OPTIONS: "-DJSON_TestStandards=17 -DJSON_TestShard=1/2"
      GENERATOR: Visual Studio 15 2017

 init:
@@ -66,7 +81,7 @@ install:
  - if "%platform%"=="x86"    set GENERATOR_PLATFORM=Win32

 before_build:
-  - cmake . -G "%GENERATOR%" -A "%GENERATOR_PLATFORM%" -DCMAKE_CXX_FLAGS="%CXX_FLAGS%" -DCMAKE_IGNORE_PATH="C:/Program Files/Git/usr/bin" -DJSON_BuildTests=On "%CMAKE_OPTIONS%"
+  - cmake . -G "%GENERATOR%" -A "%GENERATOR_PLATFORM%" -DCMAKE_CXX_FLAGS="%CXX_FLAGS%" -DCMAKE_IGNORE_PATH="C:/Program Files/Git/usr/bin" -DJSON_BuildTests=On %CMAKE_OPTIONS%

 build_script:
  - cmake --build . --config "%configuration%" --parallel 2
@@ -376,7 +376,7 @@ add_custom_target(ci_test_coverage
 # Sanitizers.
 ###############################################################################

-set(CLANG_CXX_FLAGS_SANITIZER "-g -O1 -fsanitize=address -fsanitize=undefined -fsanitize=integer -fsanitize=nullability -fno-omit-frame-pointer -fno-sanitize-recover=all -fno-sanitize=unsigned-integer-overflow -fno-sanitize=unsigned-shift-base")
+set(CLANG_CXX_FLAGS_SANITIZER "-g -O1 -fsanitize=address -fsanitize=undefined -fsanitize=integer -fsanitize=nullability -fno-omit-frame-pointer -fno-sanitize-recover=all -fno-sanitize=unsigned-integer-overflow -fno-sanitize=unsigned-shift-base -fsanitize-ignorelist=${PROJECT_SOURCE_DIR}/cmake/clang_sanitizer_ignorelist.txt")

 add_custom_target(ci_test_clang_sanitizer
    COMMAND CXX=${CLANG_TOOL} CXXFLAGS=${CLANG_CXX_FLAGS_SANITIZER} ${CMAKE_COMMAND}
@@ -0,0 +1,8 @@
+# Sanitizer ignore list for ci_test_clang_sanitizer (-fsanitize-ignorelist).
+#
+# libstdc++ 14's <format> declares `_Scanner(basic_string_view<_CharT>, size_t __nargs = -1)`, so every std::format
+# call converts -1 to size_t, which -fsanitize=integer reports as implicit-integer-sign-change. This is
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119429, not a bug in this library. Only that check and only <format> are
+# excluded, so implicit sign changes in the library and the tests are still reported.
+[implicit-integer-sign-change]
+src:*/include/c++/*/format
@@ -250,6 +250,7 @@ INSERT INTO searchIndex(name, type, path) VALUES ('JSON_TRY_USER', 'Macro', 'api
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_USE_GLOBAL_UDLS', 'Macro', 'api/macros/json_use_global_udls/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_USE_IMPLICIT_CONVERSIONS', 'Macro', 'api/macros/json_use_implicit_conversions/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON', 'Macro', 'api/macros/json_use_legacy_discarded_value_comparison/index.html');
+INSERT INTO searchIndex(name, type, path) VALUES ('JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS', 'Macro', 'api/macros/json_use_objects_for_enum_keyed_maps/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_USE_SIMDUTF', 'Macro', 'api/macros/json_use_simdutf/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('Macros', 'Macro', 'api/macros/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE', 'Macro', 'api/macros/nlohmann_define_derived_type/index.html');
@@ -69,7 +69,7 @@ The default value is `0` (disabled — existing behavior is preserved).

 ## Examples

-??? example "Default behavior (macro not defined)"
+??? example "Example: default behavior (macro not defined)"

    Without the macro, a map with enum keys is stored as an array of pairs:

@@ -96,7 +96,7 @@ The default value is `0` (disabled — existing behavior is preserved).
    }
    ```

-??? example "Objects for enum-keyed maps (macro defined to 1)"
+??? example "Example: objects for enum-keyed maps (macro defined to 1)"

    With the macro, the same map is stored as an object:

@@ -172,7 +172,7 @@ inline void from_json(const BasicJsonType& j, EnumType& e)
          typename BasicJsonType::number_unsigned_t, underlying_type>::type;
    value_type val;
    get_arithmetic_value(j, val);
-    e = static_cast<EnumType>(static_cast<underlying_type>(val));
+    e = static_cast<EnumType>(bool_aware_static_cast<underlying_type>(val));
 }
 #endif  // JSON_DISABLE_ENUM_SERIALIZATION

@@ -365,7 +365,7 @@ inline void to_json(BasicJsonType& j, EnumType e) noexcept
 {
    using underlying_type = typename std::underlying_type<EnumType>::type;
    static constexpr value_t integral_value_t = std::is_unsigned<underlying_type>::value ? value_t::number_unsigned : value_t::number_integer;
-    external_constructor<integral_value_t>::construct(j, static_cast<underlying_type>(e));
+    external_constructor<integral_value_t>::construct(j, bool_aware_static_cast<underlying_type>(e));
 }
 #endif  // JSON_DISABLE_ENUM_SERIALIZATION

@@ -662,10 +662,11 @@ class binary_reader
        }

        // the value is -1 - number, which fits into number_integer_t
-        // whenever number does
+        // whenever number does; the outer cast undoes the integral promotion
+        // for number_integer_t types narrower than int
        if (JSON_HEDLEY_LIKELY(value_in_range_of<number_integer_t>(number)))
        {
-            return sax->number_integer(static_cast<number_integer_t>(-1) - static_cast<number_integer_t>(number));
+            return sax->number_integer(conditional_static_cast<number_integer_t>(static_cast<number_integer_t>(-1) - static_cast<number_integer_t>(number)));
        }

        // like the lexer does for JSON text, store a value too small for
@@ -4003,7 +4004,8 @@ class binary_reader
        {
            return sax->number_unsigned(static_cast<number_unsigned_t>(number));
        }
-        return emit_float(number);
+        // std::isfinite has no integer overloads in MSVC's <cmath>
+        return emit_float(static_cast<long double>(number));
    }

    /*!
@@ -4026,7 +4028,8 @@ class binary_reader
        {
            return sax->number_unsigned(static_cast<number_unsigned_t>(number));
        }
-        return emit_float(number);
+        // std::isfinite has no integer overloads in MSVC's <cmath>
+        return emit_float(static_cast<long double>(number));
    }

    /*!
@@ -4037,7 +4040,8 @@ class binary_reader
    and NaN in the input are passed on unchanged. Integers only overflow if
    number_float_t cannot represent 2^64, e.g., a half-precision type.

-    @tparam NumberType a floating-point or integer type
+    @tparam NumberType a floating-point type (emit_signed and emit_unsigned
+                       convert integers to long double first)
    @param[in] number  the number
    @return whether the SAX parser accepted the value

@@ -906,6 +906,21 @@ T conditional_static_cast(U value)
    return value;
 }

+// like conditional_static_cast, but converts to bool by comparing with zero,
+// because MSVC 2015 warns about any conversion to bool (C4800), even with an
+// explicit cast; used for enums whose underlying type is bool
+template < typename T, typename U, enable_if_t < !std::is_same<T, bool>::value, int > = 0 >
+T bool_aware_static_cast(U value)
+{
+    return conditional_static_cast<T>(value);
+}
+
+template<typename T, typename U, enable_if_t<std::is_same<T, bool>::value, int> = 0>
+bool bool_aware_static_cast(U value)
+{
+    return value != U();
+}
+
 template<typename... Types>
 using all_integral = conjunction<std::is_integral<Types>...>;

@@ -5098,7 +5098,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_le/
    template<typename ScalarType>
    requires std::is_scalar_v<ScalarType>
-    friend bool operator<=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator<=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) <= rhs;
    }
@@ -5107,7 +5107,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_ge/
    template<typename ScalarType>
    requires std::is_scalar_v<ScalarType>
-    friend bool operator>=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator>=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) >= rhs;
    }
@@ -5128,11 +5128,16 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 #endif
    }

+    // The friend comparisons with a scalar name the JSON type via decltype of
+    // their parameter in noexcept, because older MSVC versions do not see the
+    // class scope there: MSVC 2015 and 2017 take basic_json as the template,
+    // and MSVC 2019 16.0 rejects member types and template parameters.
+
    /// @brief comparison: equal
    /// @sa https://json.nlohmann.me/api/basic_json/operator_eq/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator==(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator==(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(lhs)>, ScalarType>::value)
    {
        return lhs == basic_json(rhs);
    }
@@ -5141,7 +5146,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_eq/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator==(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator==(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) == rhs;
    }
@@ -5157,7 +5162,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_ne/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator!=(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator!=(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(lhs)>, ScalarType>::value)
    {
        return lhs != basic_json(rhs);
    }
@@ -5166,7 +5171,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_ne/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator!=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator!=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) != rhs;
    }
@@ -5186,7 +5191,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_lt/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator<(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator<(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(lhs)>, ScalarType>::value)
    {
        return lhs < basic_json(rhs);
    }
@@ -5195,7 +5200,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_lt/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator<(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator<(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) < rhs;
    }
@@ -5215,7 +5220,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_le/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator<=(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator<=(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(lhs)>, ScalarType>::value)
    {
        return lhs <= basic_json(rhs);
    }
@@ -5224,7 +5229,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_le/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator<=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator<=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) <= rhs;
    }
@@ -5245,7 +5250,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_gt/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator>(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator>(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(lhs)>, ScalarType>::value)
    {
        return lhs > basic_json(rhs);
    }
@@ -5254,7 +5259,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_gt/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator>(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator>(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) > rhs;
    }
@@ -5274,7 +5279,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_ge/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator>=(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator>=(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(lhs)>, ScalarType>::value)
    {
        return lhs >= basic_json(rhs);
    }
@@ -5283,7 +5288,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_ge/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator>=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator>=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) >= rhs;
    }
@@ -5319,6 +5324,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
        return o;
    }

+#if !JSON_DELETE_DEPRECATED_FUNCTIONS
+    // the deleted version is a function template after the class, because
+    // GCC < 5 and Clang < 10 reject deleted friend functions in class templates
    /// @brief serialize to stream
    /// @sa https://json.nlohmann.me/api/operator_ltlt/
    /// @deprecated This function is deprecated since 3.0.0 and will be removed in
@@ -5327,9 +5335,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    ///             replace calls like `j >> o;` with `o << j;`.
    JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator<<(std::ostream&, const basic_json&))
    friend std::ostream& operator>>(const basic_json& j, std::ostream& o)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
    {
        return o << j;
    }
@@ -5507,6 +5512,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 #pragma clang diagnostic pop
 #endif
 #ifndef JSON_NO_IO
+#if !JSON_DELETE_DEPRECATED_FUNCTIONS
+    // the deleted version is a function template after the class, because
+    // GCC < 5 and Clang < 10 reject deleted friend functions in class templates
    /// @brief deserialize from stream
    /// @sa https://json.nlohmann.me/api/operator_gtgt/
    /// @deprecated This stream operator is deprecated since 3.0.0 and will be removed in
@@ -5515,9 +5523,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    ///             replace calls like `j << i;` with `i >> j;`.
    JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator>>(std::istream&, basic_json&))
    friend std::istream& operator<<(basic_json& j, std::istream& i)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
    {
        return operator>>(i, j);
    }
@@ -7178,6 +7183,18 @@ std::string format_as(const NLOHMANN_BASIC_JSON_TPL& j)
    return j.dump();
 }

+#if JSON_DELETE_DEPRECATED_FUNCTIONS && !defined(JSON_NO_IO)
+    /// @brief serialize to stream (deleted; use operator<<(std::ostream&, const basic_json&))
+    /// @sa https://json.nlohmann.me/api/operator_ltlt/
+    NLOHMANN_BASIC_JSON_TPL_DECLARATION
+    std::ostream& operator>>(const NLOHMANN_BASIC_JSON_TPL& j, std::ostream& o) = delete;
+
+    /// @brief deserialize from stream (deleted; use operator>>(std::istream&, basic_json&))
+    /// @sa https://json.nlohmann.me/api/operator_gtgt/
+    NLOHMANN_BASIC_JSON_TPL_DECLARATION
+    std::istream& operator<<(NLOHMANN_BASIC_JSON_TPL& j, std::istream& i) = delete;
+#endif
+
 NLOHMANN_JSON_NAMESPACE_END

 ///////////////////////
@@ -4905,6 +4905,21 @@ T conditional_static_cast(U value)
    return value;
 }

+// like conditional_static_cast, but converts to bool by comparing with zero,
+// because MSVC 2015 warns about any conversion to bool (C4800), even with an
+// explicit cast; used for enums whose underlying type is bool
+template < typename T, typename U, enable_if_t < !std::is_same<T, bool>::value, int > = 0 >
+T bool_aware_static_cast(U value)
+{
+    return conditional_static_cast<T>(value);
+}
+
+template<typename T, typename U, enable_if_t<std::is_same<T, bool>::value, int> = 0>
+bool bool_aware_static_cast(U value)
+{
+    return value != U();
+}
+
 template<typename... Types>
 using all_integral = conjunction<std::is_integral<Types>...>;

@@ -5700,7 +5715,7 @@ inline void from_json(const BasicJsonType& j, EnumType& e)
          typename BasicJsonType::number_unsigned_t, underlying_type>::type;
    value_type val;
    get_arithmetic_value(j, val);
-    e = static_cast<EnumType>(static_cast<underlying_type>(val));
+    e = static_cast<EnumType>(bool_aware_static_cast<underlying_type>(val));
 }
 #endif  // JSON_DISABLE_ENUM_SERIALIZATION

@@ -7144,7 +7159,7 @@ inline void to_json(BasicJsonType& j, EnumType e) noexcept
 {
    using underlying_type = typename std::underlying_type<EnumType>::type;
    static constexpr value_t integral_value_t = std::is_unsigned<underlying_type>::value ? value_t::number_unsigned : value_t::number_integer;
-    external_constructor<integral_value_t>::construct(j, static_cast<underlying_type>(e));
+    external_constructor<integral_value_t>::construct(j, bool_aware_static_cast<underlying_type>(e));
 }
 #endif  // JSON_DISABLE_ENUM_SERIALIZATION

@@ -14353,10 +14368,11 @@ class binary_reader
        }

        // the value is -1 - number, which fits into number_integer_t
-        // whenever number does
+        // whenever number does; the outer cast undoes the integral promotion
+        // for number_integer_t types narrower than int
        if (JSON_HEDLEY_LIKELY(value_in_range_of<number_integer_t>(number)))
        {
-            return sax->number_integer(static_cast<number_integer_t>(-1) - static_cast<number_integer_t>(number));
+            return sax->number_integer(conditional_static_cast<number_integer_t>(static_cast<number_integer_t>(-1) - static_cast<number_integer_t>(number)));
        }

        // like the lexer does for JSON text, store a value too small for
@@ -17694,7 +17710,8 @@ class binary_reader
        {
            return sax->number_unsigned(static_cast<number_unsigned_t>(number));
        }
-        return emit_float(number);
+        // std::isfinite has no integer overloads in MSVC's <cmath>
+        return emit_float(static_cast<long double>(number));
    }

    /*!
@@ -17717,7 +17734,8 @@ class binary_reader
        {
            return sax->number_unsigned(static_cast<number_unsigned_t>(number));
        }
-        return emit_float(number);
+        // std::isfinite has no integer overloads in MSVC's <cmath>
+        return emit_float(static_cast<long double>(number));
    }

    /*!
@@ -17728,7 +17746,8 @@ class binary_reader
    and NaN in the input are passed on unchanged. Integers only overflow if
    number_float_t cannot represent 2^64, e.g., a half-precision type.

-    @tparam NumberType a floating-point or integer type
+    @tparam NumberType a floating-point type (emit_signed and emit_unsigned
+                       convert integers to long double first)
    @param[in] number  the number
    @return whether the SAX parser accepted the value

@@ -32248,7 +32267,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_le/
    template<typename ScalarType>
    requires std::is_scalar_v<ScalarType>
-    friend bool operator<=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator<=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) <= rhs;
    }
@@ -32257,7 +32276,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_ge/
    template<typename ScalarType>
    requires std::is_scalar_v<ScalarType>
-    friend bool operator>=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator>=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) >= rhs;
    }
@@ -32278,11 +32297,16 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 #endif
    }

+    // The friend comparisons with a scalar name the JSON type via decltype of
+    // their parameter in noexcept, because older MSVC versions do not see the
+    // class scope there: MSVC 2015 and 2017 take basic_json as the template,
+    // and MSVC 2019 16.0 rejects member types and template parameters.
+
    /// @brief comparison: equal
    /// @sa https://json.nlohmann.me/api/basic_json/operator_eq/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator==(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator==(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(lhs)>, ScalarType>::value)
    {
        return lhs == basic_json(rhs);
    }
@@ -32291,7 +32315,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_eq/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator==(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator==(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) == rhs;
    }
@@ -32307,7 +32331,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_ne/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator!=(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator!=(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(lhs)>, ScalarType>::value)
    {
        return lhs != basic_json(rhs);
    }
@@ -32316,7 +32340,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_ne/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator!=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator!=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) != rhs;
    }
@@ -32336,7 +32360,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_lt/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator<(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator<(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(lhs)>, ScalarType>::value)
    {
        return lhs < basic_json(rhs);
    }
@@ -32345,7 +32369,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_lt/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator<(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator<(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) < rhs;
    }
@@ -32365,7 +32389,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_le/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator<=(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator<=(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(lhs)>, ScalarType>::value)
    {
        return lhs <= basic_json(rhs);
    }
@@ -32374,7 +32398,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_le/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator<=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator<=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) <= rhs;
    }
@@ -32395,7 +32419,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_gt/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator>(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator>(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(lhs)>, ScalarType>::value)
    {
        return lhs > basic_json(rhs);
    }
@@ -32404,7 +32428,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_gt/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator>(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator>(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) > rhs;
    }
@@ -32424,7 +32448,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_ge/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator>=(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator>=(const_reference lhs, ScalarType rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(lhs)>, ScalarType>::value)
    {
        return lhs >= basic_json(rhs);
    }
@@ -32433,7 +32457,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @sa https://json.nlohmann.me/api/basic_json/operator_ge/
    template<typename ScalarType, typename std::enable_if<
                 std::is_scalar<ScalarType>::value, int>::type = 0>
-    friend bool operator>=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<basic_json, ScalarType>::value)
+    friend bool operator>=(ScalarType lhs, const_reference rhs) noexcept(std::is_nothrow_constructible<detail::uncvref_t<decltype(rhs)>, ScalarType>::value)
    {
        return basic_json(lhs) >= rhs;
    }
@@ -32469,6 +32493,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
        return o;
    }

+#if !JSON_DELETE_DEPRECATED_FUNCTIONS
+    // the deleted version is a function template after the class, because
+    // GCC < 5 and Clang < 10 reject deleted friend functions in class templates
    /// @brief serialize to stream
    /// @sa https://json.nlohmann.me/api/operator_ltlt/
    /// @deprecated This function is deprecated since 3.0.0 and will be removed in
@@ -32477,9 +32504,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    ///             replace calls like `j >> o;` with `o << j;`.
    JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator<<(std::ostream&, const basic_json&))
    friend std::ostream& operator>>(const basic_json& j, std::ostream& o)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
    {
        return o << j;
    }
@@ -32657,6 +32681,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 #pragma clang diagnostic pop
 #endif
 #ifndef JSON_NO_IO
+#if !JSON_DELETE_DEPRECATED_FUNCTIONS
+    // the deleted version is a function template after the class, because
+    // GCC < 5 and Clang < 10 reject deleted friend functions in class templates
    /// @brief deserialize from stream
    /// @sa https://json.nlohmann.me/api/operator_gtgt/
    /// @deprecated This stream operator is deprecated since 3.0.0 and will be removed in
@@ -32665,9 +32692,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    ///             replace calls like `j << i;` with `i >> j;`.
    JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator>>(std::istream&, basic_json&))
    friend std::istream& operator<<(basic_json& j, std::istream& i)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
    {
        return operator>>(i, j);
    }
@@ -34328,6 +34352,18 @@ std::string format_as(const NLOHMANN_BASIC_JSON_TPL& j)
    return j.dump();
 }

+#if JSON_DELETE_DEPRECATED_FUNCTIONS && !defined(JSON_NO_IO)
+    /// @brief serialize to stream (deleted; use operator<<(std::ostream&, const basic_json&))
+    /// @sa https://json.nlohmann.me/api/operator_ltlt/
+    NLOHMANN_BASIC_JSON_TPL_DECLARATION
+    std::ostream& operator>>(const NLOHMANN_BASIC_JSON_TPL& j, std::ostream& o) = delete;
+
+    /// @brief deserialize from stream (deleted; use operator>>(std::istream&, basic_json&))
+    /// @sa https://json.nlohmann.me/api/operator_gtgt/
+    NLOHMANN_BASIC_JSON_TPL_DECLARATION
+    std::istream& operator<<(NLOHMANN_BASIC_JSON_TPL& j, std::istream& i) = delete;
+#endif
+
 NLOHMANN_JSON_NAMESPACE_END

 ///////////////////////
@@ -8,6 +8,7 @@ set(JSON_SIMDUTF_VERSION 9.1.0 CACHE STRING "The simdutf version used by JSON_Te

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

 # using an env var, since this will also affect targets executing cmake (such as "ci_test_compiler_default")
 if (NOT "" STREQUAL "$ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS}")
@@ -288,6 +289,33 @@ elseif(NOT json_32bit_test)
    list(FILTER files EXCLUDE REGEX src/unit-32bit.cpp)
 endif()

+# with JSON_TestShard=<index>/<count>, keep every <count>-th unit test file,
+# starting at <index> (the glob is sorted, so the split is stable)
+set(test_shard_index 0)
+if(NOT "${JSON_TestShard}" STREQUAL "")
+    if(NOT JSON_TestShard MATCHES "^([0-9]+)/([1-9][0-9]*)$")
+        message(FATAL_ERROR "JSON_TestShard must be <index>/<count>, e.g. 0/2, not '${JSON_TestShard}'.")
+    endif()
+    set(test_shard_index ${CMAKE_MATCH_1})
+    set(test_shard_count ${CMAKE_MATCH_2})
+    if(NOT test_shard_index LESS test_shard_count)
+        message(FATAL_ERROR "JSON_TestShard: the index must be less than the count, not '${JSON_TestShard}'.")
+    endif()
+    list(LENGTH files test_file_count)
+    set(shard_files "")
+    set(file_position 0)
+    foreach(file ${files})
+        math(EXPR file_shard "${file_position} % ${test_shard_count}")
+        if(file_shard EQUAL test_shard_index)
+            list(APPEND shard_files ${file})
+        endif()
+        math(EXPR file_position "${file_position} + 1")
+    endforeach()
+    set(files ${shard_files})
+    list(LENGTH files shard_file_count)
+    message(STATUS "Test shard ${JSON_TestShard}: ${shard_file_count} of ${test_file_count} unit test files")
+endif()
+
 foreach(file ${files})
    json_test_add_test_for(${file} MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force})
 endforeach()
@@ -305,6 +333,9 @@ if(json_32bit_test_only)
    return()
 endif()

+# the following variants of single test files are only built in the first shard
+if(test_shard_index EQUAL 0)
+
 # test legacy comparison of discarded values
 json_test_set_test_options(test-comparison_legacy
    COMPILE_DEFINITIONS JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON=1
@@ -332,6 +363,8 @@ json_test_add_test_for(src/unit-diagnostic-positions.cpp
    MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
 )

+endif()
+
 # *DO NOT* use json_test_set_test_options() below this line

 #############################################################################
@@ -521,6 +521,10 @@ struct countdown_allocator : std::allocator<T>

 TEST_CASE("converting a deeply nested value from another specialization fails cleanly (#5650)")
 {
+    // MSVC 2015's debug STL constructs the containers' debug proxies through
+    // the allocator in noexcept constructors, so a failing construction crashes
+    // the program there instead of throwing std::bad_alloc. Nothing to check.
+#if !(defined(_MSC_VER) && _MSC_VER < 1910 && defined(_ITERATOR_DEBUG_LEVEL) && _ITERATOR_DEBUG_LEVEL > 0)
    using countdown_json = nlohmann::basic_json<std::map,
          std::vector,
          std::string,
@@ -558,6 +562,7 @@ TEST_CASE("converting a deeply nested value from another specialization fails cl
        }
    }
    CHECK(failures > 0);
+#endif
 }

 namespace
@@ -191,8 +191,10 @@ TEST_CASE("value conversion")
    {
        enum class bool_enum : bool { off, on };

-        CHECK(json(bool_enum::off).get<bool_enum>() == bool_enum::off);
-        CHECK(json(bool_enum::on).get<bool_enum>() == bool_enum::on);
+        // the extra parentheses keep doctest from printing the enum via its
+        // underlying type, which MSVC 2015 reports as C4800
+        CHECK((json(bool_enum::off).get<bool_enum>() == bool_enum::off));
+        CHECK((json(bool_enum::on).get<bool_enum>() == bool_enum::on));
    }
 #endif

@@ -851,7 +853,10 @@ TEST_CASE("std::optional")
        CHECK_THROWS_WITH_AS(json(opt), "cannot serialize throwing_to_json_type", std::runtime_error&);

        // the conversion is noexcept exactly when converting the contained value is
+        // (MSVC 2017 evaluates the conditional noexcept of this conversion as true)
+#if !defined(_MSC_VER) || _MSC_VER >= 1920
        static_assert(!std::is_nothrow_constructible<json, const std::optional<throwing_to_json_type>&>::value);
+#endif
        static_assert(std::is_nothrow_constructible<json, const std::optional<int>&>::value);
    }
 #endif
@@ -22,6 +22,7 @@ using nlohmann::json;
 #include <cstdint>
 #include <istream>
 #include <ostream>
+#include <sstream>
 #include <string>
 #include <type_traits>
 #include <utility>
@@ -109,6 +110,10 @@ JSON_TEST_DETECT(ptr_at, std::declval<J&>().at(std::declval<const typename J::js

 TEST_CASE("JSON_DELETE_DEPRECATED_FUNCTIONS")
 {
+    // MSVC 2015 does not treat selecting a deleted function in decltype as a
+    // substitution failure, so the traits cannot tell deleted functions apart
+    // there; calling them still fails to compile
+#if !(defined(_MSC_VER) && _MSC_VER < 1910)
    SECTION("from_* with a pointer and a length")
    {
        // the overloads are deleted rather than removed, so the length cannot
@@ -197,6 +202,8 @@ TEST_CASE("JSON_DELETE_DEPRECATED_FUNCTIONS")
        CHECK(ptr_at<json>::value);
    }

+#endif
+
    SECTION("the non-deprecated functions still work")
    {
        const json j = {{"a", {1, 2}}};
@@ -210,5 +217,13 @@ TEST_CASE("JSON_DELETE_DEPRECATED_FUNCTIONS")
        CHECK(j.at(ptr) == 2);
        CHECK(j.value(ptr, 0) == 2);
        CHECK(j.contains(ptr));
+
+        std::ostringstream os;
+        os << j;
+        CHECK(os.str() == R"({"a":[1,2]})");
+        std::istringstream is(os.str());
+        json parsed;
+        is >> parsed;
+        CHECK(parsed == j);
    }
 }
@@ -1551,6 +1551,10 @@ TEST_CASE_TEMPLATE("element access 2", Json, nlohmann::json, nlohmann::ordered_j
        // count(0) used to compile and then crash instead of failing to compile
        using nlohmann::detail::is_detected;

+        // MSVC 2015 does not treat selecting a deleted function in decltype as
+        // a substitution failure, so it detects the deleted overloads as
+        // callable; calling them still fails to compile
+#if !(defined(_MSC_VER) && _MSC_VER < 1910)
        CHECK_FALSE(is_detected<can_call_find_with_0, Json&>::value);
        CHECK_FALSE(is_detected<can_call_find_with_0, const Json&>::value);
        CHECK_FALSE(is_detected<can_call_count_with_0, Json&>::value);
@@ -1562,6 +1566,7 @@ TEST_CASE_TEMPLATE("element access 2", Json, nlohmann::json, nlohmann::ordered_j

        // another integral literal type must be rejected as well, not just int
        CHECK_FALSE(is_detected<can_call_contains_with_0L, Json&>::value);
+#endif

        // the valid overloads must remain callable
        CHECK(is_detected<can_call_find, Json&, const char*>::value);
Author	SHA1	Message	Date
Niels Lohmann	8c05e40cae	Split the Visual Studio 2017 AppVeyor jobs in two The VS 2017 jobs hit AppVeyor's 60-minute limit per job while still compiling the tests (77 of about 108 test targets after 58 minutes). They pass /std:c++17 for everything anyway, so build only the C++17 variant of each test (JSON_TestStandards=17), and split the unit test files across two jobs each with the new JSON_TestShard=<index>/<count> option, which keeps every <count>-th test file starting at <index>. The extra variants of single test files are built in shard 0 only. CMAKE_OPTIONS is no longer quoted in appveyor.yml, so that it can hold more than one option. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-05 17:44:51 +02:00
Niels Lohmann	1f086dec2b	Skip deleted-function detection checks on MSVC 2015 MSVC 2015 does not treat selecting a deleted function in decltype as a substitution failure, so the detection traits in unit-delete_deprecated_functions (#5755) and the integral-key checks in unit-element_access2 (#5657) report deleted overloads as callable there. Calling them still fails to compile. Skip those checks for _MSC_VER < 1910, and use the stream operators for real in the runtime section, so MSVC 2015 still compiles them with the macro set. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-05 14:58:12 +02:00
Niels Lohmann	336c808485	Skip the #5650 allocator test on MSVC 2015 debug builds MSVC 2015's debug STL constructs the containers' debug proxies through the allocator in noexcept constructors, so countdown_allocator's failing construction crashes test-allocator (SIGSEGV) instead of throwing std::bad_alloc. Use the guard #5585 uses for the same reason. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-05 13:49:28 +02:00
Niels Lohmann	556027f109	Avoid MSVC 2015's C4800 for enums with underlying type bool MSVC 2015 warns about any conversion to bool (C4800), even with an explicit cast, so the enum conversions from #5754 (#5671) failed the AppVeyor build with /WX. Convert to bool by comparing with zero via the new detail::bool_aware_static_cast, and keep doctest from printing the enum in the test. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-05 13:29:32 +02:00
Niels Lohmann	413dd2d2c9	Re-amalgamate Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-05 13:00:09 +02:00
Niels Lohmann	98eff63537	Fix the AppVeyor (MSVC 2015-2019) build - binary_reader: emit_signed/emit_unsigned pass integers that do not fit the number types to emit_float as long double, because MSVC's <cmath> has no integer overloads of std::isfinite (C2668 'fpclassify'), from #5607 - scalar comparisons: the friend operators take the JSON type for their noexcept from their parameter, because MSVC 2015/2017 take basic_json as the class template there (C3203) and MSVC 2019 16.0 does not see member types or template parameters, from #5751 - unit-conversions2: skip the !is_nothrow_constructible static_assert for std::optional on MSVC 2017, which evaluates the conditional noexcept as true (C2607), from #5754 Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-05 12:57:44 +02:00
Niels Lohmann	f88e209ea9	Ignore libstdc++'s <format> sign change in the sanitizer job libstdc++ 14's <format> initializes a size_t parameter with -1 (GCC bug 119429), so every std::format call fails ci_test_clang_sanitizer under -fsanitize=integer (test-std-format_cpp20). Exclude only the implicit-integer-sign-change check and only that header via -fsanitize-ignorelist. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-05 12:36:10 +02:00
Niels Lohmann	d5a1c5d149	Fix CI on develop after #5600 , #5607 , and #5755 - binary_reader: cast the result of -1 - number back to number_integer_t, because a number_integer_t narrower than int is promoted to int, which GCC's -Warith-conversion rejects (ci_test_gcc, ci_test_standards_gcc) - JSON_DELETE_DEPRECATED_FUNCTIONS: declare the deleted stream operators as function templates at namespace scope, because GCC < 5 rejects deleted friend functions ("can't initialize friend function") and Clang 7-9 report a redefinition when a class template has a deleted friend function - docs: give the examples of JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS "Example:" titles and add the page to the docset (style_check) Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-05 10:37:17 +02:00