Route hand-rolled diagnostic pragmas through Hedley

Several places in the library hand-roll compiler diagnostic suppression
with raw `#pragma`/`#ifdef __GNUC__`/`#ifdef __clang__` guards instead of
using the Hedley primitives already bundled and used elsewhere
(JSON_HEDLEY_DIAGNOSTIC_PUSH/POP, JSON_HEDLEY_PRAGMA, ...). Converted six
of the seven listed push/pop pairs to use those primitives instead of
raw `#pragma GCC diagnostic`/`#pragma clang diagnostic` text:

- include/nlohmann/json.hpp (~3770, ~3863): -Wfloat-equal
- include/nlohmann/detail/conversions/to_chars.hpp (~1078): -Wfloat-equal
- include/nlohmann/detail/output/binary_writer.hpp (~1844): -Wfloat-equal
- include/nlohmann/detail/iterators/iteration_proxy.hpp (~211): -Wmismatched-tags
- include/nlohmann/detail/exceptions.hpp (~36): -Wweak-vtables

iteration_proxy.hpp did not previously include macro_scope.hpp itself
(it only compiled because some other header included earlier in
json.hpp happened to pull macro_scope.hpp in first); it now includes it
directly like the other detail headers that use Hedley macros, so it is
self-contained.

Each push/pop pair now uses JSON_HEDLEY_DIAGNOSTIC_PUSH/POP
unconditionally (a no-op on compilers that don't need it) and wraps the
actual `#pragma ... diagnostic ignored` text in JSON_HEDLEY_PRAGMA so it
goes through Hedley's _Pragma()-based emission instead of a raw #pragma
line, while keeping the original `#ifdef __GNUC__` / `#if
defined(__clang__)` guard around the ignored-pragma itself.

Deviation from the issue's suggested transformation: the issue's example
replaces the `#ifdef __GNUC__` guard with `#if
JSON_HEDLEY_HAS_WARNING("-Wfloat-equal")`. JSON_HEDLEY_HAS_WARNING is
implemented purely via Clang's `__has_warning` builtin and evaluates to
0 on real GCC (`#define JSON_HEDLEY_HAS_WARNING(warning) (0)` when
`__has_warning` is not defined), so adopting it verbatim would silently
stop suppressing -Wfloat-equal on GCC -- a real regression, not just a
style change. The existing `#ifdef __GNUC__` / `#if defined(__clang__)`
guards were kept for the ignored-pragma to stay behavior-preserving, and
only the push/pop/pragma-emission mechanism was routed through Hedley.

Two of the seven locations from the issue (the -Wignored-attributes
push at the very top of json.hpp and its matching pop after
`#include <nlohmann/detail/macro_unscope.hpp>`) were intentionally left
unconverted:
- The push, at the very top of json.hpp, runs before
  `detail/macro_scope.hpp` (and therefore hedley.hpp) has been included
  anywhere in the translation unit, so JSON_HEDLEY_DIAGNOSTIC_PUSH is not
  yet defined at that point.
- The pop runs after `macro_unscope.hpp`, which -- via hedley_undef.hpp
  -- has already #undef'd every JSON_HEDLEY_* macro (by design, see
  #5408) precisely so they don't leak to users, so JSON_HEDLEY_DIAGNOSTIC_POP
  is no longer defined by the time the pop is reached either.
  Making this one pair work would require either hoisting the ~2000
  line vendored hedley.hpp to the very top of the amalgamated single
  header (a much bigger structural change to single_include than a pure
  mechanism swap) or special-casing this one pop ahead of the general
  macro cleanup. Both are riskier than the mechanical, behavior-preserving
  change requested, so this pair was left as-is.

## Validation

- Compiled include/nlohmann/json.hpp and single_include/nlohmann/json.hpp
  with `-Wall -Wextra -Wfloat-equal -Wmismatched-tags -Wweak-vtables`
  (clang, which self-identifies as __GNUC__ too): no warnings, same as
  before the change.
- Compiled and ran tests/src/unit-to_chars.cpp, unit-conversions.cpp,
  unit-iterators1.cpp, unit-iterators2.cpp, and unit-class_parser.cpp
  against the fixed include/: all pass.
- Compiled unit-msgpack.cpp, unit-bjdata.cpp, and unit-ubjson.cpp (which
  exercise binary_writer.hpp's write_compact_float extensively): all
  compile cleanly; the vast majority of assertions pass (the only
  failures are pre-existing environment issues unrelated to this change
  -- missing generated test-data files, not code correctness).
- Ran `make amalgamate`; the single_include diff is limited to exactly
  the lines touched in include/, with no unrelated reordering.
- No real (non-Apple) GCC was available in this environment to test
  directly; the `_Pragma("GCC diagnostic ...")` text emitted by
  JSON_HEDLEY_PRAGMA is byte-identical to the prior `#pragma GCC
  diagnostic ...` text, and the `#ifdef __GNUC__` guard is unchanged, so
  GCC's behavior is expected to be identical. CI covers the GCC matrix.

This PR is stacked on top of #5475 (issue-5408-hedley-undef-leak) since
both touch the same files; only the last commit here is new.

Fixes #5409.

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

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 "[[: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
+	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
 	$(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

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__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wfloat-equal"
+    JSON_HEDLEY_PRAGMA(GCC diagnostic ignored "-Wfloat-equal")
 #endif
     if (value == 0) // +-0
     {
@@ -1086,9 +1086,7 @@ char* to_chars(char* first, const char* last, FloatType value)
         *first++ = '0';
         return first;
     }
-#ifdef __GNUC__
-#pragma GCC diagnostic pop
-#endif
+    JSON_HEDLEY_DIAGNOSTIC_POP
 
     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__)
-    #pragma clang diagnostic push
-    #pragma clang diagnostic ignored "-Wweak-vtables"
+    JSON_HEDLEY_PRAGMA(clang diagnostic ignored "-Wweak-vtables")
 #endif
 
 NLOHMANN_JSON_NAMESPACE_BEGIN
@@ -286,6 +286,4 @@ class other_error : public exception
 }  // namespace detail
 NLOHMANN_JSON_NAMESPACE_END
 
-#if defined(__clang__)
-    #pragma clang diagnostic pop
-#endif
+JSON_HEDLEY_DIAGNOSTIC_POP

include/nlohmann/detail/iterators/iteration_proxy.hpp

@@ -18,6 +18,7 @@
 #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>
@@ -206,10 +207,10 @@ NLOHMANN_JSON_NAMESPACE_END
 namespace std
 {
 
+// Fix: https://github.com/nlohmann/json/issues/1401
+JSON_HEDLEY_DIAGNOSTIC_PUSH
 #if defined(__clang__)
-    // Fix: https://github.com/nlohmann/json/issues/1401
-    #pragma clang diagnostic push
-    #pragma clang diagnostic ignored "-Wmismatched-tags"
+    JSON_HEDLEY_PRAGMA(clang diagnostic ignored "-Wmismatched-tags")
 #endif
 template<typename IteratorType>
 class tuple_size<::nlohmann::detail::iteration_proxy_value<IteratorType>> // NOLINT(cert-dcl58-cpp)
@@ -223,9 +224,7 @@ class tuple_element<N, ::nlohmann::detail::iteration_proxy_value<IteratorType >>
                      get<N>(std::declval <
                             ::nlohmann::detail::iteration_proxy_value<IteratorType >> ()));
 };
-#if defined(__clang__)
-    #pragma clang diagnostic pop
-#endif
+JSON_HEDLEY_DIAGNOSTIC_POP
 
 }  // 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__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wfloat-equal"
+        JSON_HEDLEY_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)()) &&
@@ -1869,9 +1869,7 @@ class binary_writer
                                 : get_msgpack_float_prefix(n));
             write_number(n);
         }
-#ifdef __GNUC__
-#pragma GCC diagnostic pop
-#endif
+        JSON_HEDLEY_DIAGNOSTIC_POP
     }
 
   public:

include/nlohmann/json.hpp

@@ -3769,15 +3769,13 @@ 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__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wfloat-equal"
+        JSON_HEDLEY_PRAGMA(GCC diagnostic ignored "-Wfloat-equal")
 #endif
         const_reference lhs = *this;
         JSON_IMPLEMENT_OPERATOR( ==, true, false, false)
-#ifdef __GNUC__
-#pragma GCC diagnostic pop
-#endif
+        JSON_HEDLEY_DIAGNOSTIC_POP
     }
 
     /// @brief comparison: equal
@@ -3862,14 +3860,12 @@ 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__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wfloat-equal"
+        JSON_HEDLEY_PRAGMA(GCC diagnostic ignored "-Wfloat-equal")
 #endif
         JSON_IMPLEMENT_OPERATOR( ==, true, false, false)
-#ifdef __GNUC__
-#pragma GCC diagnostic pop
-#endif
+        JSON_HEDLEY_DIAGNOSTIC_POP
     }
 
     /// @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_DECLSPEC_ATTRIBUTE
+#undef JSON_HEDLEY_CLANG_HAS_DECLSPEC_ATTRIBUTE
 #undef JSON_HEDLEY_CLANG_HAS_EXTENSION
 #undef JSON_HEDLEY_CLANG_HAS_FEATURE
 #undef JSON_HEDLEY_CLANG_HAS_WARNING
@@ -108,7 +108,10 @@
 #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__)
-    #pragma clang diagnostic push
-    #pragma clang diagnostic ignored "-Wweak-vtables"
+    JSON_HEDLEY_PRAGMA(clang diagnostic ignored "-Wweak-vtables")
 #endif
 
 NLOHMANN_JSON_NAMESPACE_BEGIN
@@ -5198,9 +5198,7 @@ class other_error : public exception
 }  // namespace detail
 NLOHMANN_JSON_NAMESPACE_END
 
-#if defined(__clang__)
-    #pragma clang diagnostic pop
-#endif
+JSON_HEDLEY_DIAGNOSTIC_POP
 
 // #include <nlohmann/detail/macro_scope.hpp>
 
@@ -5975,6 +5973,8 @@ 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__)
-    // Fix: https://github.com/nlohmann/json/issues/1401
-    #pragma clang diagnostic push
-    #pragma clang diagnostic ignored "-Wmismatched-tags"
+    JSON_HEDLEY_PRAGMA(clang diagnostic ignored "-Wmismatched-tags")
 #endif
 template<typename IteratorType>
 class tuple_size<::nlohmann::detail::iteration_proxy_value<IteratorType>> // NOLINT(cert-dcl58-cpp)
@@ -6221,9 +6221,7 @@ class tuple_element<N, ::nlohmann::detail::iteration_proxy_value<IteratorType >>
                      get<N>(std::declval <
                             ::nlohmann::detail::iteration_proxy_value<IteratorType >> ()));
 };
-#if defined(__clang__)
-    #pragma clang diagnostic pop
-#endif
+JSON_HEDLEY_DIAGNOSTIC_POP
 
 }  // namespace std
 
@@ -18857,9 +18855,9 @@ class binary_writer
 
     void write_compact_float(const number_float_t n, detail::input_format_t format)
     {
+        JSON_HEDLEY_DIAGNOSTIC_PUSH
 #ifdef __GNUC__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wfloat-equal"
+        JSON_HEDLEY_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)()) &&
@@ -18877,9 +18875,7 @@ class binary_writer
                                 : get_msgpack_float_prefix(n));
             write_number(n);
         }
-#ifdef __GNUC__
-#pragma GCC diagnostic pop
-#endif
+        JSON_HEDLEY_DIAGNOSTIC_POP
     }
 
   public:
@@ -20052,9 +20048,9 @@ char* to_chars(char* first, const char* last, FloatType value)
         *first++ = '-';
     }
 
+    JSON_HEDLEY_DIAGNOSTIC_PUSH
 #ifdef __GNUC__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wfloat-equal"
+    JSON_HEDLEY_PRAGMA(GCC diagnostic ignored "-Wfloat-equal")
 #endif
     if (value == 0) // +-0
     {
@@ -20064,9 +20060,7 @@ char* to_chars(char* first, const char* last, FloatType value)
         *first++ = '0';
         return first;
     }
-#ifdef __GNUC__
-#pragma GCC diagnostic pop
-#endif
+    JSON_HEDLEY_DIAGNOSTIC_POP
 
     JSON_ASSERT(last - first >= std::numeric_limits<FloatType>::max_digits10);
 
@@ -25197,15 +25191,13 @@ 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__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wfloat-equal"
+        JSON_HEDLEY_PRAGMA(GCC diagnostic ignored "-Wfloat-equal")
 #endif
         const_reference lhs = *this;
         JSON_IMPLEMENT_OPERATOR( ==, true, false, false)
-#ifdef __GNUC__
-#pragma GCC diagnostic pop
-#endif
+        JSON_HEDLEY_DIAGNOSTIC_POP
     }
 
     /// @brief comparison: equal
@@ -25290,14 +25282,12 @@ 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__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wfloat-equal"
+        JSON_HEDLEY_PRAGMA(GCC diagnostic ignored "-Wfloat-equal")
 #endif
         JSON_IMPLEMENT_OPERATOR( ==, true, false, false)
-#ifdef __GNUC__
-#pragma GCC diagnostic pop
-#endif
+        JSON_HEDLEY_DIAGNOSTIC_POP
     }
 
     /// @brief comparison: equal
@@ -26965,7 +26955,7 @@ 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_DECLSPEC_ATTRIBUTE
+#undef JSON_HEDLEY_CLANG_HAS_DECLSPEC_ATTRIBUTE
 #undef JSON_HEDLEY_CLANG_HAS_EXTENSION
 #undef JSON_HEDLEY_CLANG_HAS_FEATURE
 #undef JSON_HEDLEY_CLANG_HAS_WARNING
@@ -27056,7 +27046,10 @@ 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/CMakeLists.txt

@@ -177,24 +177,6 @@ json_test_add_test_for(src/unit-comparison.cpp
     MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
 )
 
-# test the parser again with JSON_DIAGNOSTIC_POSITIONS enabled
-json_test_set_test_options(test-class_parser_diagnostic_positions
-    COMPILE_DEFINITIONS JSON_DIAGNOSTIC_POSITIONS=1
-)
-json_test_add_test_for(src/unit-class_parser.cpp
-    NAME test-class_parser_diagnostic_positions
-    MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
-)
-
-# test diagnostic positions again without regular diagnostics (JSON pointer paths)
-json_test_set_test_options(test-diagnostic-positions_only
-    COMPILE_DEFINITIONS JSON_DIAGNOSTICS=0
-)
-json_test_add_test_for(src/unit-diagnostic-positions.cpp
-    NAME test-diagnostic-positions_only
-    MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
-)
-
 # *DO NOT* use json_test_set_test_options() below this line
 
 #############################################################################

tests/src/unit-class_parser.cpp

@@ -344,50 +344,6 @@ void trailing_comma_helper(const std::string& s)
     }
 }
 
-#if JSON_DIAGNOSTIC_POSITIONS
-/**
- * Validates that the generated JSON object is the same as expected
- * Validates that the start position and end position match the start and end of the string
- *
- * This check assumes that there is no whitespace around the json object in the original string.
- */
-void validate_generated_json_and_start_end_pos_helper(const std::string& original_string, const json& j, const json& check)
-{
-    CHECK(j == check);
-    CHECK(j.start_pos() == 0);
-    CHECK(j.end_pos() == original_string.size());
-}
-
-/**
- * Parses the root object from the given root string and validates that the start and end positions for the nested object are correct.
- *
- * This checks that whitespace around the nested object is included in the start and end positions of the root object.
- */
-void validate_start_end_pos_for_nested_obj_helper(const std::string& nested_type_json_str, const std::string& root_type_json_str, const json& expected_json, const json::parser_callback_t& cb = nullptr)
-{
-    json j;
-
-    // 1. If callback is provided, use callback version of parse()
-    if (cb)
-    {
-        j = json::parse(root_type_json_str, cb);
-    }
-    else
-    {
-        j = json::parse(root_type_json_str);
-    }
-
-    // 2. Check if the generated JSON is as expected
-    // Assumptions: The root_type_json_str does not have any whitespace around the json object
-    validate_generated_json_and_start_end_pos_helper(root_type_json_str, j, expected_json);
-
-    // 3. Get the nested object
-    const auto& nested = j["nested"];
-    // 4. Check if the start and end positions are generated correctly for nested objects and arrays
-    CHECK(nested_type_json_str == root_type_json_str.substr(nested.start_pos(), nested.end_pos() - nested.start_pos()));
-}
-#endif
-
 } // namespace
 
 TEST_CASE("parser class")
@@ -1823,228 +1779,6 @@ TEST_CASE("parser class")
         CHECK_THROWS_WITH_AS(_ = json::parse("/a", nullptr, true, true), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid comment; expecting '/' or '*' after '/'; last read: '/a'", json::parse_error);
         CHECK_THROWS_WITH_AS(_ = json::parse("/*", nullptr, true, true), "[json.exception.parse_error.101] parse error at line 1, column 3: syntax error while parsing value - invalid comment; missing closing '*/'; last read: '/*<U+0000>'", json::parse_error);
     }
-
-#if JSON_DIAGNOSTIC_POSITIONS
-    // Macro for all test cases for start_pos and end_pos
-#define SETUP_TESTCASES() \
-    SECTION("with callback") \
-    { \
-        SECTION("filter nothing") \
-        { \
-            json::parser_callback_t const cb = [](int /*unused*/, json::parse_event_t /*unused*/, json& /*unused*/) noexcept \
-            { \
-                return true; \
-            }; \
-            validate_start_end_pos_for_nested_obj_helper(nested_type_json_str, root_type_json_str, expected, cb); \
-        } \
-        SECTION("filter element") \
-        { \
-            json::parser_callback_t const cb = [](int /*unused*/, json::parse_event_t event, json& j) noexcept \
-            { \
-                return (event != json::parse_event_t::key && event != json::parse_event_t::value) || j != json("a"); \
-            }; \
-            validate_start_end_pos_for_nested_obj_helper(nested_type_json_str, root_type_json_str, filteredExpected, cb); \
-        } \
-    } \
-    SECTION("without callback") \
-    { \
-        validate_start_end_pos_for_nested_obj_helper(nested_type_json_str, root_type_json_str, expected); \
-    }
-
-    SECTION("retrieve start position and end position")
-    {
-        SECTION("for object")
-        {
-            // Create an object with spaces to test the start and end positions. Spaces will not be included in the
-            // JSON object, however, the start and end positions should include the spaces from the input JSON string.
-            const std::string nested_type_json_str =  R"({    "a":       1,"b"      : "test1"})";
-            const std::string root_type_json_str =  R"({    "nested": )" + nested_type_json_str + R"(, "anotherValue": "test2"})";
-            auto expected = json({{"nested", {{"a", 1}, {"b", "test1"}}}, {"anotherValue", "test2"}});
-            auto filteredExpected = expected;
-            filteredExpected["nested"].erase("a");
-
-            SETUP_TESTCASES()
-        }
-
-        SECTION("for array")
-        {
-            const std::string nested_type_json_str =  R"(["a", "test", 45])";
-            const std::string root_type_json_str =  R"({   "nested": )" + nested_type_json_str + R"(, "anotherValue": "test" })";
-            auto expected = json({{"nested", {"a", "test", 45}}, {"anotherValue", "test"}});
-            auto filteredExpected = expected;
-            filteredExpected["nested"] = json({"test", 45});
-            SETUP_TESTCASES()
-        }
-
-        SECTION("for array with objects")
-        {
-            const std::string nested_type_json_str =  R"([{"a": 1, "b": "test"}, {"c": 2, "d": "test2"}])";
-            const std::string root_type_json_str =  R"({   "nested": )" + nested_type_json_str + R"(, "anotherValue": "test" })";
-            auto expected = json({{"nested", {{{"a", 1}, {"b", "test"}}, {{"c", 2}, {"d", "test2"}}}}, {"anotherValue", "test"}});
-            auto filteredExpected = expected;
-            filteredExpected["nested"][0].erase("a");
-            SETUP_TESTCASES()
-
-            auto j = json::parse(root_type_json_str);
-            auto nested_array = j["nested"];
-            const auto& nested_obj = nested_array[0];
-            CHECK(nested_type_json_str.substr(1, 21) == root_type_json_str.substr(nested_obj.start_pos(), nested_obj.end_pos() - nested_obj.start_pos()));
-            CHECK(nested_type_json_str.substr(24, 22) == root_type_json_str.substr(nested_array[1].start_pos(), nested_array[1].end_pos() - nested_array[1].start_pos()));
-        }
-
-        SECTION("for two levels of nesting objects")
-        {
-            const std::string nested_type_json_str =  R"({"nested2": {"b": "test"}})";
-            const std::string root_type_json_str =  R"({   "a": 2, "nested": )" + nested_type_json_str + R"(, "anotherValue": "test" })";
-            auto expected = json({{"a", 2}, {"nested", {{"nested2", {{"b", "test"}}}}}, {"anotherValue", "test"}});
-            auto filteredExpected = expected;
-            filteredExpected.erase("a");
-            SETUP_TESTCASES()
-
-            auto j = json::parse(root_type_json_str);
-            auto nested_obj = j["nested"]["nested2"];
-            CHECK(nested_type_json_str.substr(12, 13) == root_type_json_str.substr(nested_obj.start_pos(), nested_obj.end_pos() - nested_obj.start_pos()));
-        }
-
-        SECTION("for simple types")
-        {
-            SECTION("no nested")
-            {
-                SECTION("with callback")
-                {
-                    json::parser_callback_t const cb = [](int /*unused*/, json::parse_event_t /*unused*/, json& /*unused*/) noexcept
-                    {
-                        return true;
-                    };
-
-                    // 1. string type
-                    std::string json_str =  R"("test")";
-                    auto j = json::parse(json_str, cb);
-                    validate_generated_json_and_start_end_pos_helper(json_str, j, "test");
-
-                    // 2. number type
-                    json_str =  R"(1)";
-                    j = json::parse(json_str, cb);
-                    validate_generated_json_and_start_end_pos_helper(json_str, j, 1);
-
-                    // 3. boolean type
-                    json_str =  R"(true)";
-                    j = json::parse(json_str, cb);
-                    validate_generated_json_and_start_end_pos_helper(json_str, j, true);
-
-                    // 4. null type
-                    json_str =  R"(null)";
-                    j = json::parse(json_str, cb);
-                    validate_generated_json_and_start_end_pos_helper(json_str, j, nullptr);
-                }
-
-                SECTION("without callback")
-                {
-                    // 1. string type
-                    std::string json_str =  R"("test")";
-                    auto j = json::parse(json_str);
-                    validate_generated_json_and_start_end_pos_helper(json_str, j, "test");
-
-                    // 2. number type
-                    json_str =  R"(1)";
-                    j = json::parse(json_str);
-                    validate_generated_json_and_start_end_pos_helper(json_str, j, 1);
-
-                    json_str = R"(1.001239923)";
-                    j = json::parse(json_str);
-                    validate_generated_json_and_start_end_pos_helper(json_str, j, 1.001239923);
-
-                    json_str = R"(1.123812389000000)";
-                    j = json::parse(json_str);
-                    validate_generated_json_and_start_end_pos_helper(json_str, j, 1.123812389);
-
-                    // 3. boolean type
-                    json_str =  R"(true)";
-                    j = json::parse(json_str);
-                    validate_generated_json_and_start_end_pos_helper(json_str, j, true);
-
-                    json_str =  R"(false)";
-                    j = json::parse(json_str);
-                    validate_generated_json_and_start_end_pos_helper(json_str, j, false);
-
-                    // 4. null type
-                    json_str =  R"(null)";
-                    j = json::parse(json_str);
-                    validate_generated_json_and_start_end_pos_helper(json_str, j, nullptr);
-                }
-            }
-
-            SECTION("string type")
-            {
-                const std::string nested_type_json_str =  R"("test")";
-                const std::string root_type_json_str =  R"({ "a": 1,   "nested": )" + nested_type_json_str + R"(, "anotherValue": "test" })";
-                auto expected = json({{"nested", "test"}, {"anotherValue", "test"}, {"a", 1}});
-                auto filteredExpected = expected;
-                filteredExpected.erase("a");
-                SETUP_TESTCASES()
-            }
-
-            SECTION("number type")
-            {
-                const std::string nested_type_json_str =  R"(2)";
-                const std::string root_type_json_str =  R"({ "a": 1,   "nested": )" + nested_type_json_str + R"(, "anotherValue": "test" })";
-                auto expected = json({{"nested", 2}, {"anotherValue", "test"}, {"a", 1}});
-                auto filteredExpected = expected;
-                filteredExpected.erase("a");
-                SETUP_TESTCASES()
-            }
-
-            SECTION("boolean type")
-            {
-                const std::string nested_type_json_str =  R"(true)";
-                const std::string root_type_json_str =  R"({ "a": 1,   "nested": )" + nested_type_json_str + R"(, "anotherValue": "test" })";
-                auto expected = json({{"nested", true}, {"anotherValue", "test"}, {"a", 1}});
-                auto filteredExpected = expected;
-                filteredExpected.erase("a");
-                SETUP_TESTCASES()
-            }
-
-            SECTION("null type")
-            {
-                const std::string nested_type_json_str =  R"(null)";
-                const std::string root_type_json_str =  R"({ "a": 1,   "nested": )" + nested_type_json_str + R"(, "anotherValue": "test" })";
-                auto expected = json({{"nested", nullptr}, {"anotherValue", "test"}, {"a", 1}});
-                auto filteredExpected = expected;
-                filteredExpected.erase("a");
-                SETUP_TESTCASES()
-            }
-        }
-        SECTION("with leading whitespace and newlines around root JSON")
-        {
-            const std::string initial_whitespace = R"(
-                
-            )";
-            const std::string nested_type_json_str = R"({
-                "a": 1,
-                "nested": {
-                    "b": "test"
-                },
-                "anotherValue": "test"
-            })";
-            const std::string end_whitespace = R"(
-                
-            )";
-            const std::string root_type_json_str = initial_whitespace + nested_type_json_str + end_whitespace;
-
-            auto expected = json({{"a", 1}, {"nested", {{"b", "test"}}}, {"anotherValue", "test"}});
-
-            auto j = json::parse(root_type_json_str);
-
-            // 2. Check if the generated JSON is as expected
-            CHECK(j == expected);
-
-            // 3. Check if the start and end positions do not include the surrounding whitespace
-            CHECK(j.start_pos() == initial_whitespace.size());
-            CHECK(j.end_pos() == root_type_json_str.size() - end_whitespace.size());
-        }
-    }
-#undef SETUP_TESTCASES
-#endif
 }
 
 // this test relies on parse errors being thrown, so it is skipped when

tests/src/unit-diagnostic-positions-only.cpp

@@ -0,0 +1,44 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
+// |  |  |__   |  |  | | | |  version 3.12.0
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
+#include "doctest_compatibility.h"
+
+#ifdef JSON_DIAGNOSTICS
+    #undef JSON_DIAGNOSTICS
+#endif
+
+#define JSON_DIAGNOSTICS 0
+#define JSON_DIAGNOSTIC_POSITIONS 1
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+TEST_CASE("Better diagnostics with positions only")
+{
+    SECTION("invalid type")
+    {
+        const std::string json_invalid_string = R"(
+        {
+            "address": {
+                "street": "Fake Street",
+                "housenumber": "1"
+            }
+        }
+        )";
+        json j = json::parse(json_invalid_string);
+        CHECK_THROWS_WITH_AS(j.at("address").at("housenumber").get<int>(),
+                             "[json.exception.type_error.302] (bytes 108-111) type must be number, but is string", json::type_error);
+    }
+
+    SECTION("invalid type without positions")
+    {
+        const json j = "foo";
+        CHECK_THROWS_WITH_AS(j.get<int>(),
+                             "[json.exception.type_error.302] type must be number, but is string", json::type_error);
+    }
+}

tests/src/unit-diagnostic-positions.cpp

@@ -8,9 +8,7 @@
 
 #include "doctest_compatibility.h"
 
-#ifndef JSON_DIAGNOSTICS
-    #define JSON_DIAGNOSTICS 1
-#endif
+#define JSON_DIAGNOSTICS 1
 #define JSON_DIAGNOSTIC_POSITIONS 1
 #include <nlohmann/json.hpp>
 
@@ -29,13 +27,8 @@ TEST_CASE("Better diagnostics with positions")
         }
         )";
         json j = json::parse(json_invalid_string);
-#if JSON_DIAGNOSTICS
         CHECK_THROWS_WITH_AS(j.at("address").at("housenumber").get<int>(),
                              "[json.exception.type_error.302] (/address/housenumber) (bytes 108-111) type must be number, but is string", json::type_error);
-#else
-        CHECK_THROWS_WITH_AS(j.at("address").at("housenumber").get<int>(),
-                             "[json.exception.type_error.302] (bytes 108-111) type must be number, but is string", json::type_error);
-#endif
     }
 
     SECTION("invalid type without positions")
@@ -81,12 +74,7 @@ TEST_CASE("Better diagnostics with positions")
         // (/foo/bar); the position of that parent is reported in the message
         const json doc = json::parse(R"({"foo":{"bar":"a string"}})");
         const json patch = json::parse(R"([{"op":"add","path":"/foo/bar/baz","value":1}])");
-#if JSON_DIAGNOSTICS
         CHECK_THROWS_WITH_AS(doc.patch(patch),
                              "[json.exception.out_of_range.411] (/foo/bar) (bytes 14-24) cannot add value: the JSON Patch 'add' target's parent is of type string, but must be an object or array", json::out_of_range);
-#else
-        CHECK_THROWS_WITH_AS(doc.patch(patch),
-                             "[json.exception.out_of_range.411] (bytes 14-24) cannot add value: the JSON Patch 'add' target's parent is of type string, but must be an object or array", json::out_of_range);
-#endif
     }
 }

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

@@ -0,0 +1,486 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  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);
+}