Guard patch_inplace() partial-application test against JSON_NOEXCEPTION

The "distinguishing contract vs patch(): partial application on
failure" test relies on doc.patch_inplace(patch) actually throwing so
the partially-applied state can be observed right after the throw
point. Under ci_test_noexceptions, JSON_THROW() calls std::abort()
instead of throwing, and doctest's --no-throw test filter (which that
CI job passes) makes CHECK_THROWS_AS() a no-op that never even
evaluates its expression -- so patch_inplace() is never called and the
follow-up assertions fail against the untouched original document.

Guard the whole SECTION with #if !defined(JSON_NOEXCEPTION), following
the same convention already used elsewhere in the test suite (e.g.
unit-class_parser.cpp) for exception-dependent tests.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

.github/workflows/ubuntu.yml

@@ -100,7 +100,7 @@ jobs:
     container: ubuntu:focal
     strategy:
       matrix:
-        target: [ci_cmake_flags, ci_test_diagnostics, ci_test_diagnostic_positions, ci_test_noexceptions, ci_test_noimplicitconversions, ci_test_legacycomparison, ci_test_noglobaludls]
+        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_skiplibraryversioncheck]
     steps:
       - name: Install build-essential
         run: apt-get update ; apt-get install -y build-essential unzip wget git libssl-dev

Makefile

@@ -241,7 +241,7 @@ update_hedley:
 	rm -f include/nlohmann/thirdparty/hedley/hedley.hpp include/nlohmann/thirdparty/hedley/hedley_undef.hpp
 	curl https://raw.githubusercontent.com/nemequ/hedley/master/hedley.h -o include/nlohmann/thirdparty/hedley/hedley.hpp
 	$(SED) -i 's/HEDLEY_/JSON_HEDLEY_/g' include/nlohmann/thirdparty/hedley/hedley.hpp
-	grep -oE "#[[:blank:]]*define[[:blank:]]+JSON_HEDLEY_[A-Za-z0-9_]+" include/nlohmann/thirdparty/hedley/hedley.hpp | awk '{print $$NF}' | grep -v "__" | sort -u | $(SED) 's/^/#undef /' > include/nlohmann/thirdparty/hedley/hedley_undef.hpp
+	grep "[[:blank:]]*#[[:blank:]]*undef" include/nlohmann/thirdparty/hedley/hedley.hpp | grep -v "__" | sort | uniq | $(SED) 's/ //g' | $(SED) 's/undef/undef /g' > include/nlohmann/thirdparty/hedley/hedley_undef.hpp
 	$(SED) -i '1s/^/#pragma once\n\n/' include/nlohmann/thirdparty/hedley/hedley.hpp
 	$(SED) -i '1s/^/#pragma once\n\n/' include/nlohmann/thirdparty/hedley/hedley_undef.hpp
 	$(MAKE) amalgamate

cmake/ci.cmake

@@ -242,6 +242,40 @@ add_custom_target(ci_test_noglobaludls
     COMMENT "Compile and test with global UDLs disabled"
 )
 
+###############################################################################
+# Disable enum serialization.
+###############################################################################
+
+add_custom_target(ci_test_disableenumserialization
+    COMMAND ${CMAKE_COMMAND}
+    -DCMAKE_BUILD_TYPE=Debug -GNinja
+    -DJSON_BuildTests=ON -DJSON_FastTests=ON -DJSON_DisableEnumSerialization=ON
+    -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_disableenumserialization
+    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_disableenumserialization
+    COMMAND cd ${PROJECT_BINARY_DIR}/build_disableenumserialization && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
+    COMMENT "Compile and test with enum serialization disabled"
+)
+
+###############################################################################
+# Skip the multiple-inclusion library version check.
+###############################################################################
+
+# tests/src/skip_library_version_check.cpp deliberately simulates a scenario
+# (mixing two differently-versioned inclusions of the library in one
+# translation unit) that unavoidably triggers the compiler's own "macro
+# redefined" warning, so -- unlike the ci_test_* targets above -- it is
+# compiled directly here, with a modest warning set, instead of being folded
+# into the library's own -Weverything/-Werror unit test matrix.
+add_custom_target(ci_test_skiplibraryversioncheck
+    COMMAND ${CMAKE_COMMAND} -E make_directory ${PROJECT_BINARY_DIR}/skip_library_version_check
+    COMMAND ${CMAKE_CXX_COMPILER} -std=c++11 -Wall -Wextra
+        -I${PROJECT_SOURCE_DIR}/include
+        ${PROJECT_SOURCE_DIR}/tests/src/skip_library_version_check.cpp
+        -o ${PROJECT_BINARY_DIR}/skip_library_version_check/skip_library_version_check
+    COMMAND ${PROJECT_BINARY_DIR}/skip_library_version_check/skip_library_version_check
+    COMMENT "Compile and run a translation unit simulating a mismatched library version, with JSON_SKIP_LIBRARY_VERSION_CHECK defined"
+)
+
 ###############################################################################
 # Coverage.
 ###############################################################################

include/nlohmann/detail/conversions/to_chars.hpp

@@ -1074,9 +1074,9 @@ char* to_chars(char* first, const char* last, FloatType value)
         *first++ = '-';
     }
 
-    JSON_HEDLEY_DIAGNOSTIC_PUSH
 #ifdef __GNUC__
-    JSON_HEDLEY_PRAGMA(GCC diagnostic ignored "-Wfloat-equal")
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
 #endif
     if (value == 0) // +-0
     {
@@ -1086,7 +1086,9 @@ char* to_chars(char* first, const char* last, FloatType value)
         *first++ = '0';
         return first;
     }
-    JSON_HEDLEY_DIAGNOSTIC_POP
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
 
     JSON_ASSERT(last - first >= std::numeric_limits<FloatType>::max_digits10);
 

include/nlohmann/detail/exceptions.hpp

@@ -32,9 +32,9 @@
 // functions to. As a result, we suppress this warning here to avoid client
 // code stumbling over this. See https://github.com/nlohmann/json/issues/4087
 // for a discussion.
-JSON_HEDLEY_DIAGNOSTIC_PUSH
 #if defined(__clang__)
-    JSON_HEDLEY_PRAGMA(clang diagnostic ignored "-Wweak-vtables")
+    #pragma clang diagnostic push
+    #pragma clang diagnostic ignored "-Wweak-vtables"
 #endif
 
 NLOHMANN_JSON_NAMESPACE_BEGIN
@@ -286,4 +286,6 @@ class other_error : public exception
 }  // namespace detail
 NLOHMANN_JSON_NAMESPACE_END
 
-JSON_HEDLEY_DIAGNOSTIC_POP
+#if defined(__clang__)
+    #pragma clang diagnostic pop
+#endif

include/nlohmann/detail/iterators/iteration_proxy.hpp

@@ -18,7 +18,6 @@
 #endif
 
 #include <nlohmann/detail/abi_macros.hpp>
-#include <nlohmann/detail/macro_scope.hpp>
 #include <nlohmann/detail/meta/type_traits.hpp>
 #include <nlohmann/detail/string_utils.hpp>
 #include <nlohmann/detail/value_t.hpp>
@@ -207,10 +206,10 @@ NLOHMANN_JSON_NAMESPACE_END
 namespace std
 {
 
-// Fix: https://github.com/nlohmann/json/issues/1401
-JSON_HEDLEY_DIAGNOSTIC_PUSH
 #if defined(__clang__)
-    JSON_HEDLEY_PRAGMA(clang diagnostic ignored "-Wmismatched-tags")
+    // Fix: https://github.com/nlohmann/json/issues/1401
+    #pragma clang diagnostic push
+    #pragma clang diagnostic ignored "-Wmismatched-tags"
 #endif
 template<typename IteratorType>
 class tuple_size<::nlohmann::detail::iteration_proxy_value<IteratorType>> // NOLINT(cert-dcl58-cpp)
@@ -224,7 +223,9 @@ class tuple_element<N, ::nlohmann::detail::iteration_proxy_value<IteratorType >>
                      get<N>(std::declval <
                             ::nlohmann::detail::iteration_proxy_value<IteratorType >> ()));
 };
-JSON_HEDLEY_DIAGNOSTIC_POP
+#if defined(__clang__)
+    #pragma clang diagnostic pop
+#endif
 
 }  // namespace std
 

include/nlohmann/detail/output/binary_writer.hpp

@@ -1849,9 +1849,9 @@ class binary_writer
 
     void write_compact_float(const number_float_t n, detail::input_format_t format)
     {
-        JSON_HEDLEY_DIAGNOSTIC_PUSH
 #ifdef __GNUC__
-        JSON_HEDLEY_PRAGMA(GCC diagnostic ignored "-Wfloat-equal")
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
 #endif
         if (!std::isfinite(n) || ((static_cast<double>(n) >= static_cast<double>(std::numeric_limits<float>::lowest()) &&
                                    static_cast<double>(n) <= static_cast<double>((std::numeric_limits<float>::max)()) &&
@@ -1869,7 +1869,9 @@ class binary_writer
                                 : get_msgpack_float_prefix(n));
             write_number(n);
         }
-        JSON_HEDLEY_DIAGNOSTIC_POP
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
     }
 
   public:

include/nlohmann/json.hpp

@@ -3769,13 +3769,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/operator_eq/
     bool operator==(const_reference rhs) const noexcept
     {
-        JSON_HEDLEY_DIAGNOSTIC_PUSH
 #ifdef __GNUC__
-        JSON_HEDLEY_PRAGMA(GCC diagnostic ignored "-Wfloat-equal")
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
 #endif
         const_reference lhs = *this;
         JSON_IMPLEMENT_OPERATOR( ==, true, false, false)
-        JSON_HEDLEY_DIAGNOSTIC_POP
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
     }
 
     /// @brief comparison: equal
@@ -3860,12 +3862,14 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/operator_eq/
     friend bool operator==(const_reference lhs, const_reference rhs) noexcept
     {
-        JSON_HEDLEY_DIAGNOSTIC_PUSH
 #ifdef __GNUC__
-        JSON_HEDLEY_PRAGMA(GCC diagnostic ignored "-Wfloat-equal")
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
 #endif
         JSON_IMPLEMENT_OPERATOR( ==, true, false, false)
-        JSON_HEDLEY_DIAGNOSTIC_POP
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
     }
 
     /// @brief comparison: equal

include/nlohmann/thirdparty/hedley/hedley_undef.hpp

@@ -17,7 +17,7 @@
 #undef JSON_HEDLEY_CLANG_HAS_ATTRIBUTE
 #undef JSON_HEDLEY_CLANG_HAS_BUILTIN
 #undef JSON_HEDLEY_CLANG_HAS_CPP_ATTRIBUTE
-#undef JSON_HEDLEY_CLANG_HAS_DECLSPEC_ATTRIBUTE
+#undef JSON_HEDLEY_CLANG_HAS_DECLSPEC_DECLSPEC_ATTRIBUTE
 #undef JSON_HEDLEY_CLANG_HAS_EXTENSION
 #undef JSON_HEDLEY_CLANG_HAS_FEATURE
 #undef JSON_HEDLEY_CLANG_HAS_WARNING
@@ -108,10 +108,7 @@
 #undef JSON_HEDLEY_PELLES_VERSION_CHECK
 #undef JSON_HEDLEY_PGI_VERSION
 #undef JSON_HEDLEY_PGI_VERSION_CHECK
-#undef JSON_HEDLEY_PRAGMA
 #undef JSON_HEDLEY_PREDICT
-#undef JSON_HEDLEY_PREDICT_FALSE
-#undef JSON_HEDLEY_PREDICT_TRUE
 #undef JSON_HEDLEY_PRINTF_FORMAT
 #undef JSON_HEDLEY_PRIVATE
 #undef JSON_HEDLEY_PUBLIC

single_include/nlohmann/json.hpp

@@ -4944,9 +4944,9 @@ NLOHMANN_JSON_NAMESPACE_END
 // functions to. As a result, we suppress this warning here to avoid client
 // code stumbling over this. See https://github.com/nlohmann/json/issues/4087
 // for a discussion.
-JSON_HEDLEY_DIAGNOSTIC_PUSH
 #if defined(__clang__)
-    JSON_HEDLEY_PRAGMA(clang diagnostic ignored "-Wweak-vtables")
+    #pragma clang diagnostic push
+    #pragma clang diagnostic ignored "-Wweak-vtables"
 #endif
 
 NLOHMANN_JSON_NAMESPACE_BEGIN
@@ -5198,7 +5198,9 @@ class other_error : public exception
 }  // namespace detail
 NLOHMANN_JSON_NAMESPACE_END
 
-JSON_HEDLEY_DIAGNOSTIC_POP
+#if defined(__clang__)
+    #pragma clang diagnostic pop
+#endif
 
 // #include <nlohmann/detail/macro_scope.hpp>
 
@@ -5973,8 +5975,6 @@ NLOHMANN_JSON_NAMESPACE_END
 
 // #include <nlohmann/detail/abi_macros.hpp>
 
-// #include <nlohmann/detail/macro_scope.hpp>
-
 // #include <nlohmann/detail/meta/type_traits.hpp>
 
 // #include <nlohmann/detail/string_utils.hpp>
@@ -6204,10 +6204,10 @@ NLOHMANN_JSON_NAMESPACE_END
 namespace std
 {
 
-// Fix: https://github.com/nlohmann/json/issues/1401
-JSON_HEDLEY_DIAGNOSTIC_PUSH
 #if defined(__clang__)
-    JSON_HEDLEY_PRAGMA(clang diagnostic ignored "-Wmismatched-tags")
+    // Fix: https://github.com/nlohmann/json/issues/1401
+    #pragma clang diagnostic push
+    #pragma clang diagnostic ignored "-Wmismatched-tags"
 #endif
 template<typename IteratorType>
 class tuple_size<::nlohmann::detail::iteration_proxy_value<IteratorType>> // NOLINT(cert-dcl58-cpp)
@@ -6221,7 +6221,9 @@ class tuple_element<N, ::nlohmann::detail::iteration_proxy_value<IteratorType >>
                      get<N>(std::declval <
                             ::nlohmann::detail::iteration_proxy_value<IteratorType >> ()));
 };
-JSON_HEDLEY_DIAGNOSTIC_POP
+#if defined(__clang__)
+    #pragma clang diagnostic pop
+#endif
 
 }  // namespace std
 
@@ -18855,9 +18857,9 @@ class binary_writer
 
     void write_compact_float(const number_float_t n, detail::input_format_t format)
     {
-        JSON_HEDLEY_DIAGNOSTIC_PUSH
 #ifdef __GNUC__
-        JSON_HEDLEY_PRAGMA(GCC diagnostic ignored "-Wfloat-equal")
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
 #endif
         if (!std::isfinite(n) || ((static_cast<double>(n) >= static_cast<double>(std::numeric_limits<float>::lowest()) &&
                                    static_cast<double>(n) <= static_cast<double>((std::numeric_limits<float>::max)()) &&
@@ -18875,7 +18877,9 @@ class binary_writer
                                 : get_msgpack_float_prefix(n));
             write_number(n);
         }
-        JSON_HEDLEY_DIAGNOSTIC_POP
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
     }
 
   public:
@@ -20048,9 +20052,9 @@ char* to_chars(char* first, const char* last, FloatType value)
         *first++ = '-';
     }
 
-    JSON_HEDLEY_DIAGNOSTIC_PUSH
 #ifdef __GNUC__
-    JSON_HEDLEY_PRAGMA(GCC diagnostic ignored "-Wfloat-equal")
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
 #endif
     if (value == 0) // +-0
     {
@@ -20060,7 +20064,9 @@ char* to_chars(char* first, const char* last, FloatType value)
         *first++ = '0';
         return first;
     }
-    JSON_HEDLEY_DIAGNOSTIC_POP
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
 
     JSON_ASSERT(last - first >= std::numeric_limits<FloatType>::max_digits10);
 
@@ -25191,13 +25197,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/operator_eq/
     bool operator==(const_reference rhs) const noexcept
     {
-        JSON_HEDLEY_DIAGNOSTIC_PUSH
 #ifdef __GNUC__
-        JSON_HEDLEY_PRAGMA(GCC diagnostic ignored "-Wfloat-equal")
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
 #endif
         const_reference lhs = *this;
         JSON_IMPLEMENT_OPERATOR( ==, true, false, false)
-        JSON_HEDLEY_DIAGNOSTIC_POP
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
     }
 
     /// @brief comparison: equal
@@ -25282,12 +25290,14 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/operator_eq/
     friend bool operator==(const_reference lhs, const_reference rhs) noexcept
     {
-        JSON_HEDLEY_DIAGNOSTIC_PUSH
 #ifdef __GNUC__
-        JSON_HEDLEY_PRAGMA(GCC diagnostic ignored "-Wfloat-equal")
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
 #endif
         JSON_IMPLEMENT_OPERATOR( ==, true, false, false)
-        JSON_HEDLEY_DIAGNOSTIC_POP
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
     }
 
     /// @brief comparison: equal
@@ -26955,7 +26965,7 @@ struct formatter<nlohmann::NLOHMANN_BASIC_JSON_TPL, char> // NOLINT(cert-dcl58-c
 #undef JSON_HEDLEY_CLANG_HAS_ATTRIBUTE
 #undef JSON_HEDLEY_CLANG_HAS_BUILTIN
 #undef JSON_HEDLEY_CLANG_HAS_CPP_ATTRIBUTE
-#undef JSON_HEDLEY_CLANG_HAS_DECLSPEC_ATTRIBUTE
+#undef JSON_HEDLEY_CLANG_HAS_DECLSPEC_DECLSPEC_ATTRIBUTE
 #undef JSON_HEDLEY_CLANG_HAS_EXTENSION
 #undef JSON_HEDLEY_CLANG_HAS_FEATURE
 #undef JSON_HEDLEY_CLANG_HAS_WARNING
@@ -27046,10 +27056,7 @@ struct formatter<nlohmann::NLOHMANN_BASIC_JSON_TPL, char> // NOLINT(cert-dcl58-c
 #undef JSON_HEDLEY_PELLES_VERSION_CHECK
 #undef JSON_HEDLEY_PGI_VERSION
 #undef JSON_HEDLEY_PGI_VERSION_CHECK
-#undef JSON_HEDLEY_PRAGMA
 #undef JSON_HEDLEY_PREDICT
-#undef JSON_HEDLEY_PREDICT_FALSE
-#undef JSON_HEDLEY_PREDICT_TRUE
 #undef JSON_HEDLEY_PRINTF_FORMAT
 #undef JSON_HEDLEY_PRIVATE
 #undef JSON_HEDLEY_PUBLIC

tests/src/skip_library_version_check.cpp

@@ -0,0 +1,61 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
+// |  |  |__   |  |  | | | |  version 3.12.0
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
+// Standalone compile-and-run check for the JSON_SKIP_LIBRARY_VERSION_CHECK
+// configuration macro, which (per #5423) was never exercised anywhere in the
+// test matrix.
+//
+// include/nlohmann/detail/abi_macros.hpp normally emits a #warning if
+// NLOHMANN_JSON_VERSION_MAJOR/MINOR/PATCH are already defined (as they would
+// be by an earlier inclusion of a different version of the library) with
+// values that mismatch the version about to be defined -- unless
+// JSON_SKIP_LIBRARY_VERSION_CHECK is defined, in which case the check (and
+// that #warning) is skipped.
+//
+// This file deliberately is not named tests/src/unit-*.cpp: it is compiled
+// directly (with a modest, non-strict warning set) by the dedicated
+// ci_test_skiplibraryversioncheck target in cmake/ci.cmake, rather than being
+// folded into the library's own -Weverything/-Werror unit test matrix. That
+// is because the scenario simulated here -- mixing two different, already
+// differently-versioned inclusions of the library in one translation unit --
+// unavoidably also triggers the *compiler's own* "macro redefined" warning,
+// independent of (and unaffected by) JSON_SKIP_LIBRARY_VERSION_CHECK, which
+// only ever silences the library's own #warning. Building this file under
+// -Weverything -Werror would therefore fail for a reason unrelated to the
+// macro under test.
+#define NLOHMANN_JSON_VERSION_MAJOR 0
+#define NLOHMANN_JSON_VERSION_MINOR 0
+#define NLOHMANN_JSON_VERSION_PATCH 0
+
+#define JSON_SKIP_LIBRARY_VERSION_CHECK 1
+
+#include <nlohmann/json.hpp>
+
+int main()
+{
+    // reaching this point at all already proves that the mismatched,
+    // pre-defined version macros above did not stop compilation -- which is
+    // exactly what JSON_SKIP_LIBRARY_VERSION_CHECK is for. The library must
+    // also still be fully usable.
+    const nlohmann::json j = {{"a", 1}, {"b", {1, 2, 3}}};
+    if (j.dump() != "{\"a\":1,\"b\":[1,2,3]}")
+    {
+        return 1;
+    }
+
+    // include/nlohmann/detail/abi_macros.hpp unconditionally (re)defines the
+    // version macros to the library's real, current version right after the
+    // (here, skipped) mismatch check, regardless of the deliberately wrong
+    // stand-in values defined above.
+    if (NLOHMANN_JSON_VERSION_MAJOR == 0 && NLOHMANN_JSON_VERSION_MINOR == 0 && NLOHMANN_JSON_VERSION_PATCH == 0)
+    {
+        return 1;
+    }
+
+    return 0;
+}

tests/src/unit-byte_container_with_subtype.cpp

@@ -42,6 +42,39 @@ TEST_CASE("byte_container_with_subtype")
         CHECK(container.subtype() == static_cast<subtype_type>(-1));
     }
 
+    SECTION("move semantics")
+    {
+        // the rvalue-reference constructor (without a subtype) must actually move
+        // the passed-in container rather than copy it; comparing the buffer address
+        // before and after is a stronger check than just observing the source is
+        // empty afterward, since a copy-then-clear could also leave it empty
+        {
+            std::vector<std::uint8_t> bytes = {{0xCA, 0xFE, 0xBA, 0xBE}};
+            const auto* const data_ptr = bytes.data();
+
+            nlohmann::byte_container_with_subtype<std::vector<std::uint8_t>> container(std::move(bytes));
+
+            CHECK(container.size() == 4);
+            CHECK(container.data() == data_ptr);
+            CHECK(!container.has_subtype());
+            CHECK(bytes.empty()); // NOLINT(bugprone-use-after-move,clang-analyzer-cplusplus.Move,hicpp-invalid-access-moved)
+        }
+
+        // same check for the rvalue-reference constructor that also takes a subtype
+        {
+            std::vector<std::uint8_t> bytes = {{0xCA, 0xFE, 0xBA, 0xBE}};
+            const auto* const data_ptr = bytes.data();
+
+            nlohmann::byte_container_with_subtype<std::vector<std::uint8_t>> container(std::move(bytes), 42);
+
+            CHECK(container.size() == 4);
+            CHECK(container.data() == data_ptr);
+            CHECK(container.has_subtype());
+            CHECK(container.subtype() == 42);
+            CHECK(bytes.empty()); // NOLINT(bugprone-use-after-move,clang-analyzer-cplusplus.Move,hicpp-invalid-access-moved)
+        }
+    }
+
     SECTION("comparisons")
     {
         std::vector<std::uint8_t> const bytes = {{0xCA, 0xFE, 0xBA, 0xBE}};

tests/src/unit-conversions.cpp

@@ -1761,6 +1761,33 @@ TEST_CASE("std::filesystem::path")
 }
 #endif
 
+// the ADL to_json overload for std::u8string only exists under the same guard
+// as std::filesystem::path support (it is otherwise only reached indirectly,
+// via std::filesystem::path::u8string()) -- mirror both #if conditions from
+// include/nlohmann/detail/conversions/to_json.hpp exactly
+#if JSON_HAS_FILESYSTEM || JSON_HAS_EXPERIMENTAL_FILESYSTEM
+#if defined(__cpp_lib_char8_t)
+TEST_CASE("std::u8string")
+{
+    SECTION("ascii")
+    {
+        const std::u8string s = u8"Path";
+        json const j = s;
+
+        CHECK(j.template get<std::string>() == "Path");
+    }
+
+    SECTION("utf-8")
+    {
+        const std::u8string s = u8"P\xc4\x9b\xc5\xa1ina";
+        json const j = s;
+
+        CHECK(j.template get<std::string>() == "P\xc4\x9b\xc5\xa1ina");
+    }
+}
+#endif
+#endif
+
 TEST_CASE("std::optional")
 {
     SECTION("null")

tests/src/unit-json_patch.cpp

@@ -672,6 +672,94 @@ TEST_CASE("JSON patch")
         }
     }
 
+    SECTION("patch_inplace")
+    {
+        SECTION("happy path: patch_inplace mirrors patch() on success")
+        {
+            // mirrors "A.5. Replacing a Value" above, but applies the patch with
+            // patch_inplace() to a mutable copy instead of using patch()'s
+            // returned copy
+            json doc = R"(
+                    {
+                        "baz": "qux",
+                        "foo": "bar"
+                    }
+                )"_json;
+
+            json const patch = R"(
+                    [
+                        { "op": "replace", "path": "/baz", "value": "boo" }
+                    ]
+                )"_json;
+
+            json const expected = R"(
+                    {
+                        "baz": "boo",
+                        "foo": "bar"
+                    }
+                )"_json;
+
+            doc.patch_inplace(patch);
+            CHECK(doc == expected);
+        }
+
+        // this test relies on the "test" operation actually throwing so the
+        // partial-application state can be observed right after the throw
+        // point; under JSON_NOEXCEPTION, JSON_THROW() calls std::abort()
+        // instead (there is no C++ exception to throw), and doctest's
+        // CHECK_THROWS_AS() is compiled out to a no-op that never even
+        // invokes the given expression (see doctest's "--no-throw" test
+        // filter, which ci_test_noexceptions passes) -- so patch()/
+        // patch_inplace() would never be called at all and the follow-up
+        // state assertions below would fail against the untouched original
+#if !defined(JSON_NOEXCEPTION)
+        SECTION("distinguishing contract vs patch(): partial application on failure")
+        {
+            // Unlike patch(), which is all-or-nothing because it applies the
+            // patch to an internal copy that is simply discarded when an
+            // exception is thrown (leaving the original untouched no matter
+            // what), patch_inplace() mutates the document it is called on
+            // directly and immediately, operation by operation. So if a JSON
+            // Patch fails partway through, whatever operations already
+            // succeeded remain applied -- the document is left in a partially
+            // patched state. This is empirically verified current behavior,
+            // not just documented intent, and is pinned here as such.
+            json const original = R"(
+                    {
+                        "baz": "qux",
+                        "foo": "bar"
+                    }
+                )"_json;
+
+            // the first operation ("replace") succeeds; the second ("test")
+            // fails because the value at "/baz" no longer (and never did)
+            // equal "not boo"
+            json const patch = R"(
+                    [
+                        { "op": "replace", "path": "/baz", "value": "boo" },
+                        { "op": "test", "path": "/baz", "value": "not boo" }
+                    ]
+                )"_json;
+
+            // patch() never modifies the object it is called on -- it always
+            // operates on (and returns) a separate copy, so the original is
+            // left completely untouched, regardless of success or failure
+            json copy_for_patch = original;
+            CHECK_THROWS_AS(copy_for_patch.patch(patch), json::other_error&);
+            CHECK(copy_for_patch == original);
+
+            // patch_inplace(), in contrast, already applied the successful
+            // "replace" operation to the document before the "test" operation
+            // threw -- that change is not rolled back
+            json doc = original;
+            CHECK_THROWS_AS(doc.patch_inplace(patch), json::other_error&);
+            CHECK(doc != original);
+            CHECK(doc.at("baz") == "boo");
+            CHECK(doc.at("foo") == "bar");
+        }
+#endif // !defined(JSON_NOEXCEPTION)
+    }
+
     SECTION("errors")
     {
         SECTION("unknown operation")

tests/src/unit-no-macro-leak.cpp

@@ -1,486 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-// This file makes sure that none of the internal JSON_HEDLEY_* macros (vendored
-// from https://nemequ.github.io/hedley/, see
-// include/nlohmann/thirdparty/hedley/hedley.hpp) leak into the including
-// translation unit. include/nlohmann/detail/macro_unscope.hpp is supposed to
-// #undef every JSON_HEDLEY_* macro (via hedley_undef.hpp) once json.hpp has
-// been fully processed. See https://github.com/nlohmann/json/issues/5408,
-// where JSON_HEDLEY_PRAGMA, JSON_HEDLEY_PREDICT_TRUE, JSON_HEDLEY_PREDICT_FALSE,
-// and JSON_HEDLEY_CLANG_HAS_DECLSPEC_ATTRIBUTE escaped this cleanup because
-// hedley_undef.hpp had no matching #undef for them.
-//
-// The #ifdef/#error checks below are mechanically derived from the full list
-// of macro names in hedley_undef.hpp, so every JSON_HEDLEY_* macro is covered
-// -- not just the four that leaked historically.
-
-#include "doctest_compatibility.h"
-
-#include <nlohmann/json.hpp>
-
-#ifdef JSON_HEDLEY_ALWAYS_INLINE
-    #error "JSON_HEDLEY_ALWAYS_INLINE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_ARM_VERSION
-    #error "JSON_HEDLEY_ARM_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_ARM_VERSION_CHECK
-    #error "JSON_HEDLEY_ARM_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_ARRAY_PARAM
-    #error "JSON_HEDLEY_ARRAY_PARAM must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_ASSUME
-    #error "JSON_HEDLEY_ASSUME must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_BEGIN_C_DECLS
-    #error "JSON_HEDLEY_BEGIN_C_DECLS must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CLANG_HAS_ATTRIBUTE
-    #error "JSON_HEDLEY_CLANG_HAS_ATTRIBUTE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CLANG_HAS_BUILTIN
-    #error "JSON_HEDLEY_CLANG_HAS_BUILTIN must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CLANG_HAS_CPP_ATTRIBUTE
-    #error "JSON_HEDLEY_CLANG_HAS_CPP_ATTRIBUTE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CLANG_HAS_DECLSPEC_ATTRIBUTE
-    #error "JSON_HEDLEY_CLANG_HAS_DECLSPEC_ATTRIBUTE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CLANG_HAS_EXTENSION
-    #error "JSON_HEDLEY_CLANG_HAS_EXTENSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CLANG_HAS_FEATURE
-    #error "JSON_HEDLEY_CLANG_HAS_FEATURE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CLANG_HAS_WARNING
-    #error "JSON_HEDLEY_CLANG_HAS_WARNING must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_COMPCERT_VERSION
-    #error "JSON_HEDLEY_COMPCERT_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_COMPCERT_VERSION_CHECK
-    #error "JSON_HEDLEY_COMPCERT_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CONCAT
-    #error "JSON_HEDLEY_CONCAT must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CONCAT3
-    #error "JSON_HEDLEY_CONCAT3 must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CONCAT3_EX
-    #error "JSON_HEDLEY_CONCAT3_EX must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CONCAT_EX
-    #error "JSON_HEDLEY_CONCAT_EX must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CONST
-    #error "JSON_HEDLEY_CONST must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CONSTEXPR
-    #error "JSON_HEDLEY_CONSTEXPR must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CONST_CAST
-    #error "JSON_HEDLEY_CONST_CAST must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CPP_CAST
-    #error "JSON_HEDLEY_CPP_CAST must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CRAY_VERSION
-    #error "JSON_HEDLEY_CRAY_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_CRAY_VERSION_CHECK
-    #error "JSON_HEDLEY_CRAY_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_C_DECL
-    #error "JSON_HEDLEY_C_DECL must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_DEPRECATED
-    #error "JSON_HEDLEY_DEPRECATED must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_DEPRECATED_FOR
-    #error "JSON_HEDLEY_DEPRECATED_FOR must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_DIAGNOSTIC_DISABLE_CAST_QUAL
-    #error "JSON_HEDLEY_DIAGNOSTIC_DISABLE_CAST_QUAL must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_DIAGNOSTIC_DISABLE_CPP98_COMPAT_WRAP_
-    #error "JSON_HEDLEY_DIAGNOSTIC_DISABLE_CPP98_COMPAT_WRAP_ must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_DIAGNOSTIC_DISABLE_DEPRECATED
-    #error "JSON_HEDLEY_DIAGNOSTIC_DISABLE_DEPRECATED must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_DIAGNOSTIC_DISABLE_UNKNOWN_CPP_ATTRIBUTES
-    #error "JSON_HEDLEY_DIAGNOSTIC_DISABLE_UNKNOWN_CPP_ATTRIBUTES must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_DIAGNOSTIC_DISABLE_UNKNOWN_PRAGMAS
-    #error "JSON_HEDLEY_DIAGNOSTIC_DISABLE_UNKNOWN_PRAGMAS must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_DIAGNOSTIC_DISABLE_UNUSED_FUNCTION
-    #error "JSON_HEDLEY_DIAGNOSTIC_DISABLE_UNUSED_FUNCTION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_DIAGNOSTIC_POP
-    #error "JSON_HEDLEY_DIAGNOSTIC_POP must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_DIAGNOSTIC_PUSH
-    #error "JSON_HEDLEY_DIAGNOSTIC_PUSH must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_DMC_VERSION
-    #error "JSON_HEDLEY_DMC_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_DMC_VERSION_CHECK
-    #error "JSON_HEDLEY_DMC_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_EMPTY_BASES
-    #error "JSON_HEDLEY_EMPTY_BASES must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_EMSCRIPTEN_VERSION
-    #error "JSON_HEDLEY_EMSCRIPTEN_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_EMSCRIPTEN_VERSION_CHECK
-    #error "JSON_HEDLEY_EMSCRIPTEN_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_END_C_DECLS
-    #error "JSON_HEDLEY_END_C_DECLS must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_FALL_THROUGH
-    #error "JSON_HEDLEY_FALL_THROUGH must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_FLAGS
-    #error "JSON_HEDLEY_FLAGS must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_FLAGS_CAST
-    #error "JSON_HEDLEY_FLAGS_CAST must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GCC_HAS_ATTRIBUTE
-    #error "JSON_HEDLEY_GCC_HAS_ATTRIBUTE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GCC_HAS_BUILTIN
-    #error "JSON_HEDLEY_GCC_HAS_BUILTIN must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GCC_HAS_CPP_ATTRIBUTE
-    #error "JSON_HEDLEY_GCC_HAS_CPP_ATTRIBUTE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GCC_HAS_DECLSPEC_ATTRIBUTE
-    #error "JSON_HEDLEY_GCC_HAS_DECLSPEC_ATTRIBUTE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GCC_HAS_EXTENSION
-    #error "JSON_HEDLEY_GCC_HAS_EXTENSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GCC_HAS_FEATURE
-    #error "JSON_HEDLEY_GCC_HAS_FEATURE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GCC_HAS_WARNING
-    #error "JSON_HEDLEY_GCC_HAS_WARNING must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GCC_NOT_CLANG_VERSION_CHECK
-    #error "JSON_HEDLEY_GCC_NOT_CLANG_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GCC_VERSION
-    #error "JSON_HEDLEY_GCC_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GCC_VERSION_CHECK
-    #error "JSON_HEDLEY_GCC_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GNUC_HAS_ATTRIBUTE
-    #error "JSON_HEDLEY_GNUC_HAS_ATTRIBUTE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GNUC_HAS_BUILTIN
-    #error "JSON_HEDLEY_GNUC_HAS_BUILTIN must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GNUC_HAS_CPP_ATTRIBUTE
-    #error "JSON_HEDLEY_GNUC_HAS_CPP_ATTRIBUTE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GNUC_HAS_DECLSPEC_ATTRIBUTE
-    #error "JSON_HEDLEY_GNUC_HAS_DECLSPEC_ATTRIBUTE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GNUC_HAS_EXTENSION
-    #error "JSON_HEDLEY_GNUC_HAS_EXTENSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GNUC_HAS_FEATURE
-    #error "JSON_HEDLEY_GNUC_HAS_FEATURE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GNUC_HAS_WARNING
-    #error "JSON_HEDLEY_GNUC_HAS_WARNING must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GNUC_VERSION
-    #error "JSON_HEDLEY_GNUC_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_GNUC_VERSION_CHECK
-    #error "JSON_HEDLEY_GNUC_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_HAS_ATTRIBUTE
-    #error "JSON_HEDLEY_HAS_ATTRIBUTE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_HAS_BUILTIN
-    #error "JSON_HEDLEY_HAS_BUILTIN must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_HAS_CPP_ATTRIBUTE
-    #error "JSON_HEDLEY_HAS_CPP_ATTRIBUTE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_HAS_CPP_ATTRIBUTE_NS
-    #error "JSON_HEDLEY_HAS_CPP_ATTRIBUTE_NS must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_HAS_DECLSPEC_ATTRIBUTE
-    #error "JSON_HEDLEY_HAS_DECLSPEC_ATTRIBUTE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_HAS_EXTENSION
-    #error "JSON_HEDLEY_HAS_EXTENSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_HAS_FEATURE
-    #error "JSON_HEDLEY_HAS_FEATURE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_HAS_WARNING
-    #error "JSON_HEDLEY_HAS_WARNING must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_IAR_VERSION
-    #error "JSON_HEDLEY_IAR_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_IAR_VERSION_CHECK
-    #error "JSON_HEDLEY_IAR_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_IBM_VERSION
-    #error "JSON_HEDLEY_IBM_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_IBM_VERSION_CHECK
-    #error "JSON_HEDLEY_IBM_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_IMPORT
-    #error "JSON_HEDLEY_IMPORT must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_INLINE
-    #error "JSON_HEDLEY_INLINE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_INTEL_CL_VERSION
-    #error "JSON_HEDLEY_INTEL_CL_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_INTEL_CL_VERSION_CHECK
-    #error "JSON_HEDLEY_INTEL_CL_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_INTEL_VERSION
-    #error "JSON_HEDLEY_INTEL_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_INTEL_VERSION_CHECK
-    #error "JSON_HEDLEY_INTEL_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_IS_CONSTANT
-    #error "JSON_HEDLEY_IS_CONSTANT must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_IS_CONSTEXPR_
-    #error "JSON_HEDLEY_IS_CONSTEXPR_ must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_LIKELY
-    #error "JSON_HEDLEY_LIKELY must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_MALLOC
-    #error "JSON_HEDLEY_MALLOC must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_MCST_LCC_VERSION
-    #error "JSON_HEDLEY_MCST_LCC_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_MCST_LCC_VERSION_CHECK
-    #error "JSON_HEDLEY_MCST_LCC_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_MESSAGE
-    #error "JSON_HEDLEY_MESSAGE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_MSVC_VERSION
-    #error "JSON_HEDLEY_MSVC_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_MSVC_VERSION_CHECK
-    #error "JSON_HEDLEY_MSVC_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_NEVER_INLINE
-    #error "JSON_HEDLEY_NEVER_INLINE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_NON_NULL
-    #error "JSON_HEDLEY_NON_NULL must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_NO_ESCAPE
-    #error "JSON_HEDLEY_NO_ESCAPE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_NO_RETURN
-    #error "JSON_HEDLEY_NO_RETURN must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_NO_THROW
-    #error "JSON_HEDLEY_NO_THROW must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_NULL
-    #error "JSON_HEDLEY_NULL must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_PELLES_VERSION
-    #error "JSON_HEDLEY_PELLES_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_PELLES_VERSION_CHECK
-    #error "JSON_HEDLEY_PELLES_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_PGI_VERSION
-    #error "JSON_HEDLEY_PGI_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_PGI_VERSION_CHECK
-    #error "JSON_HEDLEY_PGI_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_PRAGMA
-    #error "JSON_HEDLEY_PRAGMA must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_PREDICT
-    #error "JSON_HEDLEY_PREDICT must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_PREDICT_FALSE
-    #error "JSON_HEDLEY_PREDICT_FALSE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_PREDICT_TRUE
-    #error "JSON_HEDLEY_PREDICT_TRUE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_PRINTF_FORMAT
-    #error "JSON_HEDLEY_PRINTF_FORMAT must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_PRIVATE
-    #error "JSON_HEDLEY_PRIVATE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_PUBLIC
-    #error "JSON_HEDLEY_PUBLIC must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_PURE
-    #error "JSON_HEDLEY_PURE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_REINTERPRET_CAST
-    #error "JSON_HEDLEY_REINTERPRET_CAST must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_REQUIRE
-    #error "JSON_HEDLEY_REQUIRE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_REQUIRE_CONSTEXPR
-    #error "JSON_HEDLEY_REQUIRE_CONSTEXPR must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_REQUIRE_MSG
-    #error "JSON_HEDLEY_REQUIRE_MSG must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_RESTRICT
-    #error "JSON_HEDLEY_RESTRICT must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_RETURNS_NON_NULL
-    #error "JSON_HEDLEY_RETURNS_NON_NULL must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_SENTINEL
-    #error "JSON_HEDLEY_SENTINEL must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_STATIC_ASSERT
-    #error "JSON_HEDLEY_STATIC_ASSERT must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_STATIC_CAST
-    #error "JSON_HEDLEY_STATIC_CAST must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_STRINGIFY
-    #error "JSON_HEDLEY_STRINGIFY must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_STRINGIFY_EX
-    #error "JSON_HEDLEY_STRINGIFY_EX must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_SUNPRO_VERSION
-    #error "JSON_HEDLEY_SUNPRO_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_SUNPRO_VERSION_CHECK
-    #error "JSON_HEDLEY_SUNPRO_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TINYC_VERSION
-    #error "JSON_HEDLEY_TINYC_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TINYC_VERSION_CHECK
-    #error "JSON_HEDLEY_TINYC_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TI_ARMCL_VERSION
-    #error "JSON_HEDLEY_TI_ARMCL_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TI_ARMCL_VERSION_CHECK
-    #error "JSON_HEDLEY_TI_ARMCL_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TI_CL2000_VERSION
-    #error "JSON_HEDLEY_TI_CL2000_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TI_CL2000_VERSION_CHECK
-    #error "JSON_HEDLEY_TI_CL2000_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TI_CL430_VERSION
-    #error "JSON_HEDLEY_TI_CL430_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TI_CL430_VERSION_CHECK
-    #error "JSON_HEDLEY_TI_CL430_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TI_CL6X_VERSION
-    #error "JSON_HEDLEY_TI_CL6X_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TI_CL6X_VERSION_CHECK
-    #error "JSON_HEDLEY_TI_CL6X_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TI_CL7X_VERSION
-    #error "JSON_HEDLEY_TI_CL7X_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TI_CL7X_VERSION_CHECK
-    #error "JSON_HEDLEY_TI_CL7X_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TI_CLPRU_VERSION
-    #error "JSON_HEDLEY_TI_CLPRU_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TI_CLPRU_VERSION_CHECK
-    #error "JSON_HEDLEY_TI_CLPRU_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TI_VERSION
-    #error "JSON_HEDLEY_TI_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_TI_VERSION_CHECK
-    #error "JSON_HEDLEY_TI_VERSION_CHECK must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_UNAVAILABLE
-    #error "JSON_HEDLEY_UNAVAILABLE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_UNLIKELY
-    #error "JSON_HEDLEY_UNLIKELY must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_UNPREDICTABLE
-    #error "JSON_HEDLEY_UNPREDICTABLE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_UNREACHABLE
-    #error "JSON_HEDLEY_UNREACHABLE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_UNREACHABLE_RETURN
-    #error "JSON_HEDLEY_UNREACHABLE_RETURN must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_VERSION
-    #error "JSON_HEDLEY_VERSION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_VERSION_DECODE_MAJOR
-    #error "JSON_HEDLEY_VERSION_DECODE_MAJOR must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_VERSION_DECODE_MINOR
-    #error "JSON_HEDLEY_VERSION_DECODE_MINOR must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_VERSION_DECODE_REVISION
-    #error "JSON_HEDLEY_VERSION_DECODE_REVISION must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_VERSION_ENCODE
-    #error "JSON_HEDLEY_VERSION_ENCODE must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_WARNING
-    #error "JSON_HEDLEY_WARNING must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_WARN_UNUSED_RESULT
-    #error "JSON_HEDLEY_WARN_UNUSED_RESULT must not remain defined after including json.hpp"
-#endif
-#ifdef JSON_HEDLEY_WARN_UNUSED_RESULT_MSG
-    #error "JSON_HEDLEY_WARN_UNUSED_RESULT_MSG must not remain defined after including json.hpp"
-#endif
-
-TEST_CASE("no JSON_HEDLEY_* macro leaks after including json.hpp")
-{
-    // if this test compiles at all, none of the JSON_HEDLEY_* macros checked
-    // above remained defined after including <nlohmann/json.hpp>
-    CHECK(true);
-}

tests/src/unit-no-mem-leak-on-adl-serialize.cpp

@@ -70,7 +70,7 @@ TEST_CASE("check_for_mem_leak_on_adl_to_json-2")
     }
 }
 
-TEST_CASE("check_for_mem_leak_on_adl_to_json-2")
+TEST_CASE("check_for_mem_leak_on_adl_to_json-3")
 {
     try
     {

tests/src/unit-no_io_and_user_exceptions.cpp

@@ -0,0 +1,69 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
+// |  |  |__   |  |  | | | |  version 3.12.0
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
+// This translation unit is a dedicated, small compile-and-run check for two
+// configuration macros that (per #5423) were never exercised anywhere in the
+// test matrix:
+// - JSON_NO_IO, which removes the library's <istream>/<ostream> support
+//   (operator<<, operator>>, and the stream-based overloads of dump()/parse())
+// - the JSON_THROW_USER / JSON_TRY_USER / JSON_CATCH_USER trio, which lets a
+//   user replace the library's internal exception handling
+//
+// Both macros are about excluding/replacing a facility the library would
+// otherwise pull in on its own, and defining one has no bearing on the other,
+// so -- to keep the test matrix small -- they are exercised together in a
+// single dedicated file instead of two.
+//
+// JSON_NO_IO requires this file itself to never rely on <iostream>/<sstream>;
+// only string-based parsing/dumping is used below.
+#define JSON_NO_IO 1
+
+// The user-supplied exception macros below are a *conforming* replacement:
+// they simply forward to the real throw/try/catch keywords (via a counter so
+// the test can assert each macro was actually invoked, not just defined), so
+// every exception-related behavior the library relies on internally --
+// including rethrowing std::out_of_range as json::out_of_range in at() --
+// keeps working exactly as it would with the library's own default macros.
+static int json_throw_user_call_count = 0; // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+
+#define JSON_THROW_USER(exception) do { ++json_throw_user_call_count; throw exception; } while (false) // NOLINT(cppcoreguidelines-macro-usage)
+#define JSON_TRY_USER try // NOLINT(cppcoreguidelines-macro-usage)
+#define JSON_CATCH_USER(exception) catch (exception) // NOLINT(cppcoreguidelines-macro-usage)
+
+#include "doctest_compatibility.h"
+
+#include <nlohmann/json.hpp>
+using json = nlohmann::json;
+
+TEST_CASE("JSON_NO_IO")
+{
+    // everything that does not touch <istream>/<ostream> must keep working:
+    // parsing from and dumping to std::string
+    const json j = json::parse("{\"a\":[1,2,3],\"b\":true}");
+    CHECK(j.dump() == "{\"a\":[1,2,3],\"b\":true}");
+    CHECK(j.at("a").size() == 3);
+    CHECK(j.at("b").get<bool>() == true);
+}
+
+TEST_CASE("JSON_THROW_USER, JSON_TRY_USER, JSON_CATCH_USER")
+{
+    json_throw_user_call_count = 0;
+
+    // a parse error goes through JSON_THROW directly, i.e., through our
+    // JSON_THROW_USER override
+    CHECK_THROWS_AS(json::parse("this is not JSON"), json::parse_error&);
+    CHECK(json_throw_user_call_count > 0);
+
+    // at() on an out-of-range array index internally catches std::out_of_range
+    // (JSON_TRY_USER/JSON_CATCH_USER) and rethrows it as json::out_of_range
+    // (JSON_THROW_USER again), so this exercises all three macros together
+    const int count_before = json_throw_user_call_count;
+    const json arr = json::array({1, 2, 3});
+    CHECK_THROWS_AS(arr.at(10), json::out_of_range&);
+    CHECK(json_throw_user_call_count > count_before);
+}

tests/src/unit-regression2.cpp

@@ -18,6 +18,14 @@
 // for some reason including this after the json header leads to linker errors with VS 2017...
 #include <locale>
 
+// skip tests if JSON_DisableEnumSerialization=ON (#4384): std::byte is a
+// scoped enum, so get<std::byte>() (needed below to get<std::vector<std::byte>>()
+// from a plain JSON array, not just from an already-binary value) relies on
+// enum serialization being enabled
+#if defined(JSON_DISABLE_ENUM_SERIALIZATION) && (JSON_DISABLE_ENUM_SERIALIZATION == 1)
+    #define SKIP_TESTS_FOR_ENUM_SERIALIZATION
+#endif
+
 #define JSON_TESTS_PRIVATE
 #include <nlohmann/json.hpp>
 using json = nlohmann::json;
@@ -1136,6 +1144,7 @@ TEST_CASE("regression tests 2")
         CHECK((decoded == json_4804::array()));
     }
 
+#ifndef SKIP_TESTS_FOR_ENUM_SERIALIZATION
     SECTION("discussion #4209 - custom BinaryType direct assignment and round-tripping")
     {
         // Test that assigning a custom BinaryType directly creates a binary value, not an array
@@ -1169,6 +1178,7 @@ TEST_CASE("regression tests 2")
         CHECK(extracted[1] == std::byte{2});
         CHECK(extracted[2] == std::byte{3});
     }
+#endif
 
     SECTION("issue #5046 - implicit conversion of return json to std::optional no longer implicit")
     {

tests/src/unit-std-format.cpp

@@ -52,6 +52,23 @@ TEST_CASE("std::formatter<nlohmann::json>")
         CHECK(std::format("{:2}", j) == j.dump(2));
         CHECK(std::format("{:#2}", j) == j.dump(2));
         CHECK(std::format("{:8}", j) == j.dump(8));
+        // multi-digit widths must accumulate every digit, not just the first
+        CHECK(std::format("{:12}", j) == j.dump(12));
+        CHECK(std::format("{:#12}", j) == j.dump(12));
+        CHECK(std::format("{:10}", j) == j.dump(10));
+    }
+
+    SECTION("bare alignment with no fill character defaults to a space indent character")
+    {
+        const json j = {{"foo", 1}, {"bar", {1, 2, 3}}};
+        // without a preceding fill character, the alignment character itself must not
+        // be mistaken for the indent character -- the default space is kept
+        CHECK(std::format("{:<}", j) == j.dump());
+        CHECK(std::format("{:>}", j) == j.dump());
+        CHECK(std::format("{:^}", j) == j.dump());
+        CHECK(std::format("{:<3}", j) == j.dump(3, ' '));
+        CHECK(std::format("{:>3}", j) == j.dump(3, ' '));
+        CHECK(std::format("{:^3}", j) == j.dump(3, ' '));
     }
 
     SECTION("fill-and-align sets the indent character, like dump(indent, indent_char)")