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

@@ -1335,7 +1335,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief serialization
     /// @sa https://json.nlohmann.me/api/basic_json/dump/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     string_t dump(const int indent = -1,
                   const char indent_char = ' ',
                   const bool ensure_ascii = false,
@@ -1358,7 +1357,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return the type of the JSON value (explicit)
     /// @sa https://json.nlohmann.me/api/basic_json/type/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr value_t type() const noexcept
     {
         return m_data.m_type;
@@ -1366,7 +1364,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether type is primitive
     /// @sa https://json.nlohmann.me/api/basic_json/is_primitive/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_primitive() const noexcept
     {
         return is_null() || is_string() || is_boolean() || is_number() || is_binary();
@@ -1374,7 +1371,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether type is structured
     /// @sa https://json.nlohmann.me/api/basic_json/is_structured/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_structured() const noexcept
     {
         return is_array() || is_object();
@@ -1382,7 +1378,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is null
     /// @sa https://json.nlohmann.me/api/basic_json/is_null/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_null() const noexcept
     {
         return m_data.m_type == value_t::null;
@@ -1390,7 +1385,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is a boolean
     /// @sa https://json.nlohmann.me/api/basic_json/is_boolean/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_boolean() const noexcept
     {
         return m_data.m_type == value_t::boolean;
@@ -1398,7 +1392,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is a number
     /// @sa https://json.nlohmann.me/api/basic_json/is_number/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_number() const noexcept
     {
         return is_number_integer() || is_number_float();
@@ -1406,7 +1399,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is an integer number
     /// @sa https://json.nlohmann.me/api/basic_json/is_number_integer/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_number_integer() const noexcept
     {
         return m_data.m_type == value_t::number_integer || m_data.m_type == value_t::number_unsigned;
@@ -1414,7 +1406,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is an unsigned integer number
     /// @sa https://json.nlohmann.me/api/basic_json/is_number_unsigned/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_number_unsigned() const noexcept
     {
         return m_data.m_type == value_t::number_unsigned;
@@ -1422,7 +1413,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is a floating-point number
     /// @sa https://json.nlohmann.me/api/basic_json/is_number_float/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_number_float() const noexcept
     {
         return m_data.m_type == value_t::number_float;
@@ -1430,7 +1420,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is an object
     /// @sa https://json.nlohmann.me/api/basic_json/is_object/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_object() const noexcept
     {
         return m_data.m_type == value_t::object;
@@ -1438,7 +1427,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is an array
     /// @sa https://json.nlohmann.me/api/basic_json/is_array/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_array() const noexcept
     {
         return m_data.m_type == value_t::array;
@@ -1446,7 +1434,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is a string
     /// @sa https://json.nlohmann.me/api/basic_json/is_string/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_string() const noexcept
     {
         return m_data.m_type == value_t::string;
@@ -1454,7 +1441,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is a binary array
     /// @sa https://json.nlohmann.me/api/basic_json/is_binary/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_binary() const noexcept
     {
         return m_data.m_type == value_t::binary;
@@ -1462,7 +1448,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is discarded
     /// @sa https://json.nlohmann.me/api/basic_json/is_discarded/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_discarded() const noexcept
     {
         return m_data.m_type == value_t::discarded;
@@ -2794,7 +2779,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief returns the number of occurrences of a key in a JSON object
     /// @sa https://json.nlohmann.me/api/basic_json/count/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     size_type count(const typename object_t::key_type& key) const
     {
         // return 0 for all nonobject types
@@ -2805,7 +2789,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/count/
     template<class KeyType, detail::enable_if_t<
                  detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value, int> = 0>
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     size_type count(KeyType && key) const
     {
         // return 0 for all nonobject types
@@ -2814,7 +2797,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief check the existence of an element in a JSON object
     /// @sa https://json.nlohmann.me/api/basic_json/contains/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     bool contains(const typename object_t::key_type& key) const
     {
         return is_object() && m_data.m_value.object->find(key) != m_data.m_value.object->end();
@@ -2824,7 +2806,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/contains/
     template<class KeyType, detail::enable_if_t<
                  detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value, int> = 0>
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     bool contains(KeyType && key) const
     {
         return is_object() && m_data.m_value.object->find(std::forward<KeyType>(key)) != m_data.m_value.object->end();
@@ -2832,14 +2813,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief check the existence of an element in a JSON object given a JSON pointer
     /// @sa https://json.nlohmann.me/api/basic_json/contains/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     bool contains(const json_pointer& ptr) const
     {
         return ptr.contains(this);
     }
 
     template<typename BasicJsonType, detail::enable_if_t<detail::is_basic_json<BasicJsonType>::value, int> = 0>
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
     bool contains(const typename ::nlohmann::json_pointer<BasicJsonType>& ptr) const
     {
@@ -2995,7 +2974,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief checks whether the container is empty.
     /// @sa https://json.nlohmann.me/api/basic_json/empty/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     bool empty() const noexcept
     {
         switch (m_data.m_type)
@@ -3035,7 +3013,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief returns the number of elements
     /// @sa https://json.nlohmann.me/api/basic_json/size/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     size_type size() const noexcept
     {
         switch (m_data.m_type)
@@ -3075,7 +3052,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief returns the maximum possible number of elements
     /// @sa https://json.nlohmann.me/api/basic_json/max_size/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     size_type max_size() const noexcept
     {
         switch (m_data.m_type)
@@ -3793,15 +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
@@ -3886,14 +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
@@ -4153,7 +4125,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @brief check if the input is valid JSON
     /// @sa https://json.nlohmann.me/api/basic_json/accept/
     template<typename InputType>
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     static bool accept(InputType&& i,
                        const bool ignore_comments = false,
                        const bool ignore_trailing_commas = false)
@@ -4165,7 +4136,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/accept/
     template<typename IteratorType, typename SentinelType = IteratorType,
              detail::enable_if_t<detail::can_compare_ne<IteratorType, SentinelType>::value, int> = 0>
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     static bool accept(IteratorType first, SentinelType last,
                        const bool ignore_comments = false,
                        const bool ignore_trailing_commas = false)
@@ -4265,7 +4235,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return the type as string
     /// @sa https://json.nlohmann.me/api/basic_json/type_name/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     JSON_HEDLEY_RETURNS_NON_NULL
     const char* type_name() const noexcept
     {

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);
 
@@ -22763,7 +22757,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief serialization
     /// @sa https://json.nlohmann.me/api/basic_json/dump/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     string_t dump(const int indent = -1,
                   const char indent_char = ' ',
                   const bool ensure_ascii = false,
@@ -22786,7 +22779,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return the type of the JSON value (explicit)
     /// @sa https://json.nlohmann.me/api/basic_json/type/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr value_t type() const noexcept
     {
         return m_data.m_type;
@@ -22794,7 +22786,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether type is primitive
     /// @sa https://json.nlohmann.me/api/basic_json/is_primitive/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_primitive() const noexcept
     {
         return is_null() || is_string() || is_boolean() || is_number() || is_binary();
@@ -22802,7 +22793,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether type is structured
     /// @sa https://json.nlohmann.me/api/basic_json/is_structured/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_structured() const noexcept
     {
         return is_array() || is_object();
@@ -22810,7 +22800,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is null
     /// @sa https://json.nlohmann.me/api/basic_json/is_null/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_null() const noexcept
     {
         return m_data.m_type == value_t::null;
@@ -22818,7 +22807,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is a boolean
     /// @sa https://json.nlohmann.me/api/basic_json/is_boolean/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_boolean() const noexcept
     {
         return m_data.m_type == value_t::boolean;
@@ -22826,7 +22814,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is a number
     /// @sa https://json.nlohmann.me/api/basic_json/is_number/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_number() const noexcept
     {
         return is_number_integer() || is_number_float();
@@ -22834,7 +22821,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is an integer number
     /// @sa https://json.nlohmann.me/api/basic_json/is_number_integer/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_number_integer() const noexcept
     {
         return m_data.m_type == value_t::number_integer || m_data.m_type == value_t::number_unsigned;
@@ -22842,7 +22828,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is an unsigned integer number
     /// @sa https://json.nlohmann.me/api/basic_json/is_number_unsigned/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_number_unsigned() const noexcept
     {
         return m_data.m_type == value_t::number_unsigned;
@@ -22850,7 +22835,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is a floating-point number
     /// @sa https://json.nlohmann.me/api/basic_json/is_number_float/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_number_float() const noexcept
     {
         return m_data.m_type == value_t::number_float;
@@ -22858,7 +22842,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is an object
     /// @sa https://json.nlohmann.me/api/basic_json/is_object/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_object() const noexcept
     {
         return m_data.m_type == value_t::object;
@@ -22866,7 +22849,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is an array
     /// @sa https://json.nlohmann.me/api/basic_json/is_array/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_array() const noexcept
     {
         return m_data.m_type == value_t::array;
@@ -22874,7 +22856,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is a string
     /// @sa https://json.nlohmann.me/api/basic_json/is_string/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_string() const noexcept
     {
         return m_data.m_type == value_t::string;
@@ -22882,7 +22863,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is a binary array
     /// @sa https://json.nlohmann.me/api/basic_json/is_binary/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_binary() const noexcept
     {
         return m_data.m_type == value_t::binary;
@@ -22890,7 +22870,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return whether value is discarded
     /// @sa https://json.nlohmann.me/api/basic_json/is_discarded/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     constexpr bool is_discarded() const noexcept
     {
         return m_data.m_type == value_t::discarded;
@@ -24222,7 +24201,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief returns the number of occurrences of a key in a JSON object
     /// @sa https://json.nlohmann.me/api/basic_json/count/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     size_type count(const typename object_t::key_type& key) const
     {
         // return 0 for all nonobject types
@@ -24233,7 +24211,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/count/
     template<class KeyType, detail::enable_if_t<
                  detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value, int> = 0>
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     size_type count(KeyType && key) const
     {
         // return 0 for all nonobject types
@@ -24242,7 +24219,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief check the existence of an element in a JSON object
     /// @sa https://json.nlohmann.me/api/basic_json/contains/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     bool contains(const typename object_t::key_type& key) const
     {
         return is_object() && m_data.m_value.object->find(key) != m_data.m_value.object->end();
@@ -24252,7 +24228,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/contains/
     template<class KeyType, detail::enable_if_t<
                  detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value, int> = 0>
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     bool contains(KeyType && key) const
     {
         return is_object() && m_data.m_value.object->find(std::forward<KeyType>(key)) != m_data.m_value.object->end();
@@ -24260,14 +24235,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief check the existence of an element in a JSON object given a JSON pointer
     /// @sa https://json.nlohmann.me/api/basic_json/contains/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     bool contains(const json_pointer& ptr) const
     {
         return ptr.contains(this);
     }
 
     template<typename BasicJsonType, detail::enable_if_t<detail::is_basic_json<BasicJsonType>::value, int> = 0>
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
     bool contains(const typename ::nlohmann::json_pointer<BasicJsonType>& ptr) const
     {
@@ -24423,7 +24396,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief checks whether the container is empty.
     /// @sa https://json.nlohmann.me/api/basic_json/empty/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     bool empty() const noexcept
     {
         switch (m_data.m_type)
@@ -24463,7 +24435,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief returns the number of elements
     /// @sa https://json.nlohmann.me/api/basic_json/size/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     size_type size() const noexcept
     {
         switch (m_data.m_type)
@@ -24503,7 +24474,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief returns the maximum possible number of elements
     /// @sa https://json.nlohmann.me/api/basic_json/max_size/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     size_type max_size() const noexcept
     {
         switch (m_data.m_type)
@@ -25221,15 +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
@@ -25314,14 +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
@@ -25581,7 +25547,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @brief check if the input is valid JSON
     /// @sa https://json.nlohmann.me/api/basic_json/accept/
     template<typename InputType>
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     static bool accept(InputType&& i,
                        const bool ignore_comments = false,
                        const bool ignore_trailing_commas = false)
@@ -25593,7 +25558,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/accept/
     template<typename IteratorType, typename SentinelType = IteratorType,
              detail::enable_if_t<detail::can_compare_ne<IteratorType, SentinelType>::value, int> = 0>
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     static bool accept(IteratorType first, SentinelType last,
                        const bool ignore_comments = false,
                        const bool ignore_trailing_commas = false)
@@ -25693,7 +25657,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief return the type as string
     /// @sa https://json.nlohmann.me/api/basic_json/type_name/
-    JSON_HEDLEY_WARN_UNUSED_RESULT
     JSON_HEDLEY_RETURNS_NON_NULL
     const char* type_name() const noexcept
     {
@@ -26992,7 +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
@@ -27083,7 +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/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);
+}

tests/src/unit-regression2.cpp

@@ -639,8 +639,7 @@ TEST_CASE("regression tests 2")
                 s += static_cast<char>(i);
             }
             dump_test["1"] = s;
-            // dump() is nodiscard; this only checks that dumping does not throw/crash
-            (void)dump_test.dump(-1, ' ', true, nlohmann::json::error_handler_t::replace);
+            dump_test.dump(-1, ' ', true, nlohmann::json::error_handler_t::replace);
         }
     }