Move the user-defined string literals to <nlohmann/json_literals.hpp>

Following the review in #5294, the literals now live in their own header
instead of being removed entirely: <nlohmann/json.hpp> includes it at the
end unless JSON_NO_AUTOMATIC_UDLS (renamed from JSON_NO_UDLS) is defined,
so a project can opt out globally and include the header only where the
literals are used.

The header only uses public and standard macros, because the library's
internal macros are undefined at the end of json.hpp and the amalgamation
inlines macro_scope.hpp only once. For the same reason, the library no
longer defines and undefines JSON_USE_GLOBAL_UDLS, so a user's definition
is still visible to the header. The single-header copy is identical to
the multi-header one, as it only includes <nlohmann/json.hpp>. The module
always exports the literals.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
This commit is contained in:
Niels Lohmann
2026-09-28 21:49:37 +02:00
parent e0ee07fe73
commit 1419aeff60
23 changed files with 418 additions and 233 deletions
+1
View File
@@ -67,6 +67,7 @@ jobs:
python3 $TOOL_DIR/amalgamate.py -c $TOOL_DIR/config_json.json -s .
python3 $TOOL_DIR/amalgamate.py -c $TOOL_DIR/config_json_fwd.json -s .
cp include/nlohmann/json_literals.hpp $INCLUDE_DIR/json_literals.hpp
# the header list of the Bazel "json" target must match the files in include/
cmake -P cmake/scripts/gen_bazel_build_file.cmake
+1
View File
@@ -65,6 +65,7 @@ cc_library(
"include/nlohmann/detail/value_t.hpp",
"include/nlohmann/json.hpp",
"include/nlohmann/json_fwd.hpp",
"include/nlohmann/json_literals.hpp",
"include/nlohmann/ordered_map.hpp",
"include/nlohmann/thirdparty/hedley/hedley.hpp",
"include/nlohmann/thirdparty/hedley/hedley_undef.hpp",
+16 -5
View File
@@ -21,6 +21,8 @@ TESTS_SRCS=$(shell find tests -type f \( -name '*.hpp' -o -name '*.cpp' -o -name
# the single headers (amalgamated from the source files)
AMALGAMATED_FILE=single_include/nlohmann/json.hpp
AMALGAMATED_FWD_FILE=single_include/nlohmann/json_fwd.hpp
# json_literals.hpp only includes <nlohmann/json.hpp>, so it is copied verbatim
AMALGAMATED_LITERALS_FILE=single_include/nlohmann/json_literals.hpp
##########################################################################
@@ -29,7 +31,7 @@ AMALGAMATED_FWD_FILE=single_include/nlohmann/json_fwd.hpp
# main target
all:
@echo "amalgamate - amalgamate files single_include/nlohmann/json{,_fwd}.hpp from the include/nlohmann sources"
@echo "amalgamate - amalgamate files single_include/nlohmann/json{,_fwd,_literals}.hpp from the include/nlohmann sources"
@echo "BUILD.bazel - regenerate the Bazel BUILD file from the include/nlohmann sources"
@echo "ChangeLog.md - generate ChangeLog file"
@echo "check-amalgamation - check whether sources have been amalgamated and BUILD.bazel is up to date"
@@ -154,14 +156,14 @@ install_astyle:
# call the Artistic Style pretty printer on all source files
pretty: install_astyle
$(ASTYLE) --project=tools/astyle/.astylerc $(SRCS) $(TESTS_SRCS) $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) docs/mkdocs/docs/examples/*.cpp
$(ASTYLE) --project=tools/astyle/.astylerc $(SRCS) $(TESTS_SRCS) $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_LITERALS_FILE) docs/mkdocs/docs/examples/*.cpp
# call the Clang-Format on all source files
pretty_format:
for FILE in $(SRCS) $(TESTS_SRCS) $(AMALGAMATED_FILE) docs/mkdocs/docs/examples/*.cpp; do echo $$FILE; clang-format -i $$FILE; done
# create single header files and pretty print
amalgamate: $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE)
amalgamate: $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_LITERALS_FILE)
$(MAKE) pretty
# call the amalgamation tool for json.hpp
@@ -172,16 +174,23 @@ $(AMALGAMATED_FILE): $(SRCS)
$(AMALGAMATED_FWD_FILE): $(SRCS)
tools/amalgamate/amalgamate.py -c tools/amalgamate/config_json_fwd.json -s . --verbose=yes
# copy json_literals.hpp
$(AMALGAMATED_LITERALS_FILE): include/nlohmann/json_literals.hpp
cp include/nlohmann/json_literals.hpp $(AMALGAMATED_LITERALS_FILE)
# check if file single_include/nlohmann/json.hpp has been amalgamated from the nlohmann sources
# Note: this target is called by Travis
check-amalgamation:
@mv $(AMALGAMATED_FILE) $(AMALGAMATED_FILE)~
@mv $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_FWD_FILE)~
@mv $(AMALGAMATED_LITERALS_FILE) $(AMALGAMATED_LITERALS_FILE)~
@$(MAKE) amalgamate
@diff $(AMALGAMATED_FILE) $(AMALGAMATED_FILE)~ || (echo "===================================================================\n Amalgamation required! Please read the contribution guidelines\n in file .github/CONTRIBUTING.md.\n===================================================================" ; mv $(AMALGAMATED_FILE)~ $(AMALGAMATED_FILE) ; false)
@diff $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_FWD_FILE)~ || (echo "===================================================================\n Amalgamation required! Please read the contribution guidelines\n in file .github/CONTRIBUTING.md.\n===================================================================" ; mv $(AMALGAMATED_FWD_FILE)~ $(AMALGAMATED_FWD_FILE) ; false)
@diff $(AMALGAMATED_LITERALS_FILE) $(AMALGAMATED_LITERALS_FILE)~ || (echo "===================================================================\n Amalgamation required! Please read the contribution guidelines\n in file .github/CONTRIBUTING.md.\n===================================================================" ; mv $(AMALGAMATED_LITERALS_FILE)~ $(AMALGAMATED_LITERALS_FILE) ; false)
@mv $(AMALGAMATED_FILE)~ $(AMALGAMATED_FILE)
@mv $(AMALGAMATED_FWD_FILE)~ $(AMALGAMATED_FWD_FILE)
@mv $(AMALGAMATED_LITERALS_FILE)~ $(AMALGAMATED_LITERALS_FILE)
@mv BUILD.bazel BUILD.bazel~
@$(MAKE) BUILD.bazel
@diff BUILD.bazel BUILD.bazel~ || (echo "===================================================================\n BUILD.bazel is out of date! Please run 'make BUILD.bazel'.\n===================================================================" ; mv BUILD.bazel~ BUILD.bazel ; false)
@@ -222,7 +231,7 @@ json.tar.xz:
# We use `-X` to make the resulting ZIP file reproducible, see
# <https://content.pivotal.io/blog/barriers-to-deterministic-reproducible-zip-files>.
include.zip: BUILD.bazel
zip -9 --recurse-paths -X include.zip $(SRCS) $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) BUILD.bazel MODULE.bazel meson.build LICENSE.MIT
zip -9 --recurse-paths -X include.zip $(SRCS) $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_LITERALS_FILE) BUILD.bazel MODULE.bazel meson.build LICENSE.MIT
# Create the files for a release and add signatures and hashes.
release: include.zip json.tar.xz
@@ -231,10 +240,12 @@ release: include.zip json.tar.xz
gpg --armor --detach-sig include.zip
gpg --armor --detach-sig $(AMALGAMATED_FILE)
gpg --armor --detach-sig $(AMALGAMATED_FWD_FILE)
gpg --armor --detach-sig $(AMALGAMATED_LITERALS_FILE)
gpg --armor --detach-sig json.tar.xz
cp $(AMALGAMATED_FILE) release_files
cp $(AMALGAMATED_FWD_FILE) release_files
mv $(AMALGAMATED_FILE).asc $(AMALGAMATED_FWD_FILE).asc json.tar.xz json.tar.xz.asc include.zip include.zip.asc release_files
cp $(AMALGAMATED_LITERALS_FILE) release_files
mv $(AMALGAMATED_FILE).asc $(AMALGAMATED_FWD_FILE).asc $(AMALGAMATED_LITERALS_FILE).asc json.tar.xz json.tar.xz.asc include.zip include.zip.asc release_files
cd release_files ; shasum -a 256 json.hpp include.zip json.tar.xz > hashes.txt
+4 -1
View File
@@ -373,9 +373,10 @@ file(GLOB_RECURSE INDENT_FILES
set(include_dir ${PROJECT_SOURCE_DIR}/single_include/nlohmann)
set(tool_dir ${PROJECT_SOURCE_DIR}/tools/amalgamate)
add_custom_target(ci_test_amalgamation
COMMAND rm -fr ${include_dir}/json.hpp~ ${include_dir}/json_fwd.hpp~
COMMAND rm -fr ${include_dir}/json.hpp~ ${include_dir}/json_fwd.hpp~ ${include_dir}/json_literals.hpp~
COMMAND cp ${include_dir}/json.hpp ${include_dir}/json.hpp~
COMMAND cp ${include_dir}/json_fwd.hpp ${include_dir}/json_fwd.hpp~
COMMAND cp ${include_dir}/json_literals.hpp ${include_dir}/json_literals.hpp~
COMMAND ${Python3_EXECUTABLE} -mvenv venv_astyle
COMMAND venv_astyle/bin/pip3 --quiet install -r ${CMAKE_SOURCE_DIR}/tools/astyle/requirements.txt
@@ -383,10 +384,12 @@ add_custom_target(ci_test_amalgamation
COMMAND ${Python3_EXECUTABLE} ${tool_dir}/amalgamate.py -c ${tool_dir}/config_json.json -s .
COMMAND ${Python3_EXECUTABLE} ${tool_dir}/amalgamate.py -c ${tool_dir}/config_json_fwd.json -s .
COMMAND cp ${PROJECT_SOURCE_DIR}/include/nlohmann/json_literals.hpp ${include_dir}/json_literals.hpp
COMMAND venv_astyle/bin/astyle --project=tools/astyle/.astylerc --suffix=none ${include_dir}/json.hpp ${include_dir}/json_fwd.hpp
COMMAND diff ${include_dir}/json.hpp~ ${include_dir}/json.hpp
COMMAND diff ${include_dir}/json_fwd.hpp~ ${include_dir}/json_fwd.hpp
COMMAND diff ${include_dir}/json_literals.hpp~ ${include_dir}/json_literals.hpp
COMMAND venv_astyle/bin/astyle --project=tools/astyle/.astylerc --suffix=orig ${INDENT_FILES}
COMMAND for FILE in `find . -name '*.orig'`\; do false \; done
+1 -1
View File
@@ -28,9 +28,9 @@ header. See also the [macro overview page](../../features/macros.md).
- [**JSON_HAS_RANGES**](json_has_ranges.md) - control `std::ranges` support
- [**JSON_HAS_STD_FORMAT**](json_has_std_format.md) - control `std::format`/`std::formatter` support
- [**JSON_HAS_THREE_WAY_COMPARISON**](json_has_three_way_comparison.md) - control 3-way comparison support
- [**JSON_NO_AUTOMATIC_UDLS**](json_no_automatic_udls.md) - do not include the user-defined string literals (UDLs) automatically
- [**JSON_NO_IO**](json_no_io.md) - switch off functions relying on certain C++ I/O headers
- [**JSON_NO_THREAD_LOCAL**](json_no_thread_local.md) - switch off the use of `thread_local` storage
- [**JSON_NO_UDLS**](json_no_udls.md) - leave out the user-defined string literals (UDLs) to reduce compile time
- [**JSON_SKIP_UNSUPPORTED_COMPILER_CHECK**](json_skip_unsupported_compiler_check.md) - do not warn about unsupported compilers
- [**JSON_USE_GLOBAL_UDLS**](json_use_global_udls.md) - place user-defined string literals (UDLs) into the global namespace
- [**JSON_USE_SIMDUTF**](json_use_simdutf.md) - use the simdutf library to accelerate UTF-8 validation
@@ -0,0 +1,68 @@
# JSON_NO_AUTOMATIC_UDLS
```cpp
#define JSON_NO_AUTOMATIC_UDLS
```
When defined, `<nlohmann/json.hpp>` does not include `<nlohmann/json_literals.hpp>`, so the user-defined string
literals [`operator""_json`](../operator_literal_json.md) and
[`operator""_json_pointer`](../operator_literal_json_pointer.md) are not declared. Include
`<nlohmann/json_literals.hpp>` in the files that use them.
The literals are ordinary inline functions whose bodies call the parser, so every translation unit that includes them
instantiates the parser — even if it never parses anything itself. Defining `JSON_NO_AUTOMATIC_UDLS` for a whole project
avoids this cost in translation units that do not parse (e.g., ones that only define types and conversions or pass
`json` values around) and reduces their compile time.
## Default definition
By default, `#!cpp JSON_NO_AUTOMATIC_UDLS` is not defined, and `<nlohmann/json.hpp>` includes
`<nlohmann/json_literals.hpp>`.
```cpp
#undef JSON_NO_AUTOMATIC_UDLS
```
## Notes
!!! info "Header `<nlohmann/json_literals.hpp>`"
The header includes `<nlohmann/json.hpp>` itself and places the literals according to
[`JSON_USE_GLOBAL_UDLS`](json_use_global_udls.md). It is part of the multi-header sources (`include/nlohmann`)
and of the single-header sources (`single_include/nlohmann`), next to `json.hpp`.
!!! info "C++ modules"
The `nlohmann.json` [module](../../features/modules.md) always exports the literals, regardless of this macro.
## Examples
??? example
The code below includes the library without the literals and adds them in a single translation unit.
```cpp
// compiled with -DJSON_NO_AUTOMATIC_UDLS for the whole project
#include <nlohmann/json.hpp>
// this file uses the literals, so it includes them explicitly
#include <nlohmann/json_literals.hpp>
int main()
{
auto j = R"({"foo": 42})"_json;
return j.at("/foo"_json_pointer) == 42 ? 0 : 1;
}
```
Without the include of `<nlohmann/json_literals.hpp>`, the code would fail to compile.
## See also
- [`operator""_json`](../operator_literal_json.md)
- [`operator""_json_pointer`](../operator_literal_json_pointer.md)
- [`JSON_USE_GLOBAL_UDLS`](json_use_global_udls.md) - place user-defined string literals (UDLs) into the global namespace
## Version history
- Added in version 3.13.0.
@@ -1,61 +0,0 @@
# JSON_NO_UDLS
```cpp
#define JSON_NO_UDLS
```
When defined, the user-defined string literals [`operator""_json`](../operator_literal_json.md) and
[`operator""_json_pointer`](../operator_literal_json_pointer.md) are not defined, neither in the namespace
`nlohmann::literals::json_literals` nor in the global namespace (regardless of
[`JSON_USE_GLOBAL_UDLS`](json_use_global_udls.md)).
The literals are ordinary inline functions whose bodies call the parser, so every translation unit that includes the
library instantiates the parser — even if it never parses anything itself. Defining `JSON_NO_UDLS` avoids this and
reduces the compile time of such translation units (e.g., ones that only define types and conversions or pass `json`
values around). Everything else in the library is unaffected; use [`parse`](../basic_json/parse.md) and the
[`json_pointer`](../json_pointer/json_pointer.md) constructor instead of the literals.
## Default definition
By default, `#!cpp JSON_NO_UDLS` is not defined.
```cpp
#undef JSON_NO_UDLS
```
## Notes
!!! info "Per translation unit"
The macro only removes declarations, so it can be defined for some translation units and not for others. Code that
uses `_json` or `_json_pointer` fails to compile when `JSON_NO_UDLS` is defined.
## Examples
??? example
The code below leaves out the user-defined string literals and uses `parse` and the `json_pointer` constructor
instead.
```cpp
#define JSON_NO_UDLS 1
#include <nlohmann/json.hpp>
int main()
{
// auto j = R"({"foo": 42})"_json; // This line would fail to compile
auto j = nlohmann::json::parse(R"({"foo": 42})");
auto p = nlohmann::json::json_pointer("/foo");
return j.at(p) == 42 ? 0 : 1;
}
```
## See also
- [`operator""_json`](../operator_literal_json.md)
- [`operator""_json_pointer`](../operator_literal_json_pointer.md)
- [`JSON_USE_GLOBAL_UDLS`](json_use_global_udls.md) - place user-defined string literals (UDLs) into the global namespace
## Version history
- Added in version 3.13.0.
@@ -15,7 +15,7 @@ The default value is `1`.
#define JSON_USE_GLOBAL_UDLS 1
```
When the macro is not defined, the library will define it to its default value.
When the macro is not defined, the library behaves as if it were defined to its default value.
## Notes
@@ -34,7 +34,8 @@ When the macro is not defined, the library will define it to its default value.
!!! info "Leaving out the literals"
If [`JSON_NO_UDLS`](json_no_udls.md) is defined, the literals are not defined at all and this macro has no effect.
If [`JSON_NO_AUTOMATIC_UDLS`](json_no_automatic_udls.md) is defined, the literals are only declared where
`<nlohmann/json_literals.hpp>` is included; this macro then applies to that header.
## Examples
@@ -96,7 +97,7 @@ When the macro is not defined, the library will define it to its default value.
- [`operator""_json`](../operator_literal_json.md)
- [`operator""_json_pointer`](../operator_literal_json_pointer.md)
- [`JSON_NO_UDLS`](json_no_udls.md) - leave out the user-defined string literals entirely
- [`JSON_NO_AUTOMATIC_UDLS`](json_no_automatic_udls.md) - do not include the user-defined string literals automatically
- [:simple-cmake: JSON_GlobalUDLs](../../integration/cmake.md#json_globaludls) - CMake option to control the macro
## Version history
@@ -18,8 +18,9 @@ using namespace nlohmann;
```
This is suggested to ease migration to the next major version release of the library. See
[`JSON_USE_GLOBAL_UDLS`](macros/json_use_global_udls.md#notes) for details. The operator is not defined if
[`JSON_NO_UDLS`](macros/json_no_udls.md) is defined.
[`JSON_USE_GLOBAL_UDLS`](macros/json_use_global_udls.md#notes) for details. The operator is declared in header
`<nlohmann/json_literals.hpp>`, which `<nlohmann/json.hpp>` includes unless
[`JSON_NO_AUTOMATIC_UDLS`](macros/json_no_automatic_udls.md) is defined.
## Parameters
@@ -60,7 +61,8 @@ Linear.
## See also
- [Creating JSON values](../features/creating_values.md) - the article on creating JSON values
- [JSON_NO_UDLS](macros/json_no_udls.md) - leave out the user-defined string literals
- [JSON_NO_AUTOMATIC_UDLS](macros/json_no_automatic_udls.md) - do not include the user-defined string literals
automatically
## Version history
@@ -17,8 +17,9 @@ using namespace nlohmann::literals::json_literals;
using namespace nlohmann;
```
This is suggested to ease migration to the next major version release of the library. See
[`JSON_USE_GLOBAL_UDLS`](macros/json_use_global_udls.md#notes) for details. The operator is not defined if
[`JSON_NO_UDLS`](macros/json_no_udls.md) is defined.
[`JSON_USE_GLOBAL_UDLS`](macros/json_use_global_udls.md#notes) for details. The operator is declared in header
`<nlohmann/json_literals.hpp>`, which `<nlohmann/json.hpp>` includes unless
[`JSON_NO_AUTOMATIC_UDLS`](macros/json_no_automatic_udls.md) is defined.
## Parameters
@@ -59,7 +60,8 @@ Linear.
## See also
- [json_pointer](json_pointer/index.md) - type to represent JSON Pointers
- [JSON_NO_UDLS](macros/json_no_udls.md) - leave out the user-defined string literals
- [JSON_NO_AUTOMATIC_UDLS](macros/json_no_automatic_udls.md) - do not include the user-defined string literals
automatically
## Version history
+9 -8
View File
@@ -83,6 +83,15 @@ When defined, default parse and serialize functions for enums are excluded and h
See [full documentation of `JSON_DISABLE_ENUM_SERIALIZATION`](../api/macros/json_disable_enum_serialization.md).
## `JSON_NO_AUTOMATIC_UDLS`
When defined, `<nlohmann/json.hpp>` does not include `<nlohmann/json_literals.hpp>` with the user-defined string literals
`operator""_json` and `operator""_json_pointer`. This reduces the compile time of translation units that do not use
them, because the literals instantiate the parser in every translation unit that includes them. Include
`<nlohmann/json_literals.hpp>` where the literals are needed.
See [full documentation of `JSON_NO_AUTOMATIC_UDLS`](../api/macros/json_no_automatic_udls.md).
## `JSON_NO_IO`
When defined, headers `<cstdio>`, `<ios>`, `<iosfwd>`, `<istream>`, and `<ostream>` are not included and parse functions
@@ -99,14 +108,6 @@ same values and the same comparisons.
See [full documentation of `JSON_NO_THREAD_LOCAL`](../api/macros/json_no_thread_local.md).
## `JSON_NO_UDLS`
When defined, the user-defined string literals `operator""_json` and `operator""_json_pointer` are left out entirely. This
reduces the compile time of translation units that do not use them, because the literals would otherwise instantiate
the parser in every translation unit that includes the library.
See [full documentation of `JSON_NO_UDLS`](../api/macros/json_no_udls.md).
## `JSON_PRECISE_STREAM_POSITION`
When defined to `1`, [`operator>>`](../api/operator_gtgt.md) and non-strict
+2 -2
View File
@@ -40,8 +40,8 @@ Only the following symbols are exported from `nlohmann.json`:
- `nlohmann::literals::json_literals::operator""_json`
- `nlohmann::literals::json_literals::operator""_json_pointer`
The two user-defined string literals are not exported if [`JSON_NO_UDLS`](../api/macros/json_no_udls.md) is defined
when building the module.
The module always exports the two user-defined string literals, even if
[`JSON_NO_AUTOMATIC_UDLS`](../api/macros/json_no_automatic_udls.md) is defined when building it.
Additionally, the following `nlohmann::detail` symbols are exported, solely to work around an MSVC compilation issue
([#3970](https://github.com/nlohmann/json/issues/3970)). They are implementation details, not part of the public API,
+4 -1
View File
@@ -15,4 +15,7 @@ Clang).
You can further use file
[`single_include/nlohmann/json_fwd.hpp`](https://github.com/nlohmann/json/blob/develop/single_include/nlohmann/json_fwd.hpp)
for forward declarations.
for forward declarations, and file
[`single_include/nlohmann/json_literals.hpp`](https://github.com/nlohmann/json/blob/develop/single_include/nlohmann/json_literals.hpp)
for the user-defined string literals if you define
[`JSON_NO_AUTOMATIC_UDLS`](../api/macros/json_no_automatic_udls.md).
+1 -1
View File
@@ -293,10 +293,10 @@ nav:
- 'JSON_HAS_STATIC_RTTI': api/macros/json_has_static_rtti.md
- 'JSON_HAS_STD_FORMAT': api/macros/json_has_std_format.md
- 'JSON_HAS_THREE_WAY_COMPARISON': api/macros/json_has_three_way_comparison.md
- 'JSON_NO_AUTOMATIC_UDLS': api/macros/json_no_automatic_udls.md
- 'JSON_NOEXCEPTION': api/macros/json_noexception.md
- 'JSON_NO_IO': api/macros/json_no_io.md
- 'JSON_NO_THREAD_LOCAL': api/macros/json_no_thread_local.md
- 'JSON_NO_UDLS': api/macros/json_no_udls.md
- 'JSON_PRECISE_STREAM_POSITION': api/macros/json_precise_stream_position.md
- 'JSON_SKIP_LIBRARY_VERSION_CHECK': api/macros/json_skip_library_version_check.md
- 'JSON_SKIP_UNSUPPORTED_COMPILER_CHECK': api/macros/json_skip_unsupported_compiler_check.md
-4
View File
@@ -915,7 +915,3 @@ void templated_json_throw(ExceptionType exception)
#ifndef JSON_DISABLE_ENUM_SERIALIZATION
#define JSON_DISABLE_ENUM_SERIALIZATION 0
#endif
#ifndef JSON_USE_GLOBAL_UDLS
#define JSON_USE_GLOBAL_UDLS 1
#endif
@@ -25,7 +25,6 @@
#undef JSON_INLINE_VARIABLE
#undef JSON_NO_UNIQUE_ADDRESS
#undef JSON_DISABLE_ENUM_SERIALIZATION
#undef JSON_USE_GLOBAL_UDLS
#ifndef JSON_TEST_KEEP_MACROS
#undef JSON_CATCH
+8 -62
View File
@@ -6423,57 +6423,6 @@ std::string format_as(const NLOHMANN_BASIC_JSON_TPL& j)
return j.dump();
}
#ifndef JSON_NO_UDLS
inline namespace literals
{
inline namespace json_literals
{
/// @brief user-defined string literal for JSON values
/// @sa https://json.nlohmann.me/api/basic_json/operator_literal_json/
JSON_HEDLEY_NON_NULL(1)
#if !defined(JSON_HEDLEY_GCC_VERSION) || JSON_HEDLEY_GCC_VERSION_CHECK(4,9,0)
inline nlohmann::json operator""_json(const char* s, std::size_t n)
#else
// GCC 4.8 requires a space between "" and suffix
inline nlohmann::json operator"" _json(const char* s, std::size_t n)
#endif
{
return nlohmann::json::parse(s, s + n);
}
#if defined(__cpp_char8_t)
JSON_HEDLEY_NON_NULL(1)
inline nlohmann::json operator""_json(const char8_t* s, std::size_t n)
{
return nlohmann::json::parse(reinterpret_cast<const char*>(s),
reinterpret_cast<const char*>(s) + n);
}
#endif
/// @brief user-defined string literal for JSON pointer
/// @sa https://json.nlohmann.me/api/basic_json/operator_literal_json_pointer/
JSON_HEDLEY_NON_NULL(1)
#if !defined(JSON_HEDLEY_GCC_VERSION) || JSON_HEDLEY_GCC_VERSION_CHECK(4,9,0)
inline nlohmann::json::json_pointer operator""_json_pointer(const char* s, std::size_t n)
#else
// GCC 4.8 requires a space between "" and suffix
inline nlohmann::json::json_pointer operator"" _json_pointer(const char* s, std::size_t n)
#endif
{
return nlohmann::json::json_pointer(std::string(s, n));
}
#if defined(__cpp_char8_t)
inline nlohmann::json::json_pointer operator""_json_pointer(const char8_t* s, std::size_t n)
{
return nlohmann::json::json_pointer(std::string(reinterpret_cast<const char*>(s), n));
}
#endif
} // namespace json_literals
} // namespace literals
#endif // JSON_NO_UDLS
NLOHMANN_JSON_NAMESPACE_END
///////////////////////
@@ -6608,17 +6557,6 @@ struct formatter<nlohmann::NLOHMANN_BASIC_JSON_TPL, char> // NOLINT(cert-dcl58-c
} // namespace std
#if JSON_USE_GLOBAL_UDLS && !defined(JSON_NO_UDLS)
#if !defined(JSON_HEDLEY_GCC_VERSION) || JSON_HEDLEY_GCC_VERSION_CHECK(4,9,0)
using nlohmann::literals::json_literals::operator""_json; // NOLINT(misc-unused-using-decls,google-global-names-in-headers)
using nlohmann::literals::json_literals::operator""_json_pointer; //NOLINT(misc-unused-using-decls,google-global-names-in-headers)
#else
// GCC 4.8 requires a space between "" and suffix
using nlohmann::literals::json_literals::operator"" _json; // NOLINT(misc-unused-using-decls,google-global-names-in-headers)
using nlohmann::literals::json_literals::operator"" _json_pointer; //NOLINT(misc-unused-using-decls,google-global-names-in-headers)
#endif
#endif
#include <nlohmann/detail/macro_unscope.hpp>
// End of GCC diagnostic pragmas for C++ modules support
@@ -6626,4 +6564,12 @@ struct formatter<nlohmann::NLOHMANN_BASIC_JSON_TPL, char> // NOLINT(cert-dcl58-c
#pragma GCC diagnostic pop
#endif
// The user-defined string literals are in a separate header, because their
// bodies instantiate the parser in every translation unit that includes them.
// Define JSON_NO_AUTOMATIC_UDLS to include <nlohmann/json_literals.hpp> only
// where needed.
#ifndef JSON_NO_AUTOMATIC_UDLS
#include <nlohmann/json_literals.hpp>
#endif
#endif // INCLUDE_NLOHMANN_JSON_HPP_
+83
View File
@@ -0,0 +1,83 @@
// __ _____ _____ _____
// __| | __| | | | 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
#ifndef INCLUDE_NLOHMANN_JSON_LITERALS_HPP_
#define INCLUDE_NLOHMANN_JSON_LITERALS_HPP_
#include <cstddef> // size_t
#include <string> // string
#include <nlohmann/json.hpp>
// This header is included at the end of <nlohmann/json.hpp> unless
// JSON_NO_AUTOMATIC_UDLS is defined, and can be included on its own after that.
// Either way, the library's internal macros are no longer defined here (and the
// amalgamation inlines macro_scope.hpp only once), so only standard and public
// macros may be used below.
NLOHMANN_JSON_NAMESPACE_BEGIN
inline namespace literals
{
inline namespace json_literals
{
/// @brief user-defined string literal for JSON values
/// @sa https://json.nlohmann.me/api/operator_literal_json/
#if !defined(__GNUC__) || defined(__clang__) || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)
inline nlohmann::json operator""_json(const char* s, std::size_t n)
#else
// GCC 4.8 requires a space between "" and suffix
inline nlohmann::json operator"" _json(const char* s, std::size_t n)
#endif
{
return nlohmann::json::parse(s, s + n);
}
#if defined(__cpp_char8_t)
inline nlohmann::json operator""_json(const char8_t* s, std::size_t n)
{
return nlohmann::json::parse(reinterpret_cast<const char*>(s),
reinterpret_cast<const char*>(s) + n);
}
#endif
/// @brief user-defined string literal for JSON pointer
/// @sa https://json.nlohmann.me/api/operator_literal_json_pointer/
#if !defined(__GNUC__) || defined(__clang__) || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)
inline nlohmann::json::json_pointer operator""_json_pointer(const char* s, std::size_t n)
#else
// GCC 4.8 requires a space between "" and suffix
inline nlohmann::json::json_pointer operator"" _json_pointer(const char* s, std::size_t n)
#endif
{
return nlohmann::json::json_pointer(std::string(s, n));
}
#if defined(__cpp_char8_t)
inline nlohmann::json::json_pointer operator""_json_pointer(const char8_t* s, std::size_t n)
{
return nlohmann::json::json_pointer(std::string(reinterpret_cast<const char*>(s), n));
}
#endif
} // namespace json_literals
} // namespace literals
NLOHMANN_JSON_NAMESPACE_END
#if !defined(JSON_USE_GLOBAL_UDLS) || JSON_USE_GLOBAL_UDLS
#if !defined(__GNUC__) || defined(__clang__) || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)
using nlohmann::literals::json_literals::operator""_json; // NOLINT(misc-unused-using-decls,google-global-names-in-headers)
using nlohmann::literals::json_literals::operator""_json_pointer; //NOLINT(misc-unused-using-decls,google-global-names-in-headers)
#else
// GCC 4.8 requires a space between "" and suffix
using nlohmann::literals::json_literals::operator"" _json; // NOLINT(misc-unused-using-decls,google-global-names-in-headers)
using nlohmann::literals::json_literals::operator"" _json_pointer; //NOLINT(misc-unused-using-decls,google-global-names-in-headers)
#endif
#endif
#endif // INCLUDE_NLOHMANN_JSON_LITERALS_HPP_
+1
View File
@@ -15,6 +15,7 @@ nlohmann_json_multiple_headers = declare_dependency(
if not meson.is_subproject()
install_headers('single_include/nlohmann/json.hpp', subdir: 'nlohmann')
install_headers('single_include/nlohmann/json_fwd.hpp', subdir: 'nlohmann')
install_headers('single_include/nlohmann/json_literals.hpp', subdir: 'nlohmann')
pkgc = import('pkgconfig')
pkgc.generate(name: 'nlohmann_json',
+93 -67
View File
@@ -3327,10 +3327,6 @@ void templated_json_throw(ExceptionType exception)
#define JSON_DISABLE_ENUM_SERIALIZATION 0
#endif
#ifndef JSON_USE_GLOBAL_UDLS
#define JSON_USE_GLOBAL_UDLS 1
#endif
#if JSON_HAS_THREE_WAY_COMPARISON
#include <compare> // partial_ordering
#endif
@@ -32504,57 +32500,6 @@ std::string format_as(const NLOHMANN_BASIC_JSON_TPL& j)
return j.dump();
}
#ifndef JSON_NO_UDLS
inline namespace literals
{
inline namespace json_literals
{
/// @brief user-defined string literal for JSON values
/// @sa https://json.nlohmann.me/api/basic_json/operator_literal_json/
JSON_HEDLEY_NON_NULL(1)
#if !defined(JSON_HEDLEY_GCC_VERSION) || JSON_HEDLEY_GCC_VERSION_CHECK(4,9,0)
inline nlohmann::json operator""_json(const char* s, std::size_t n)
#else
// GCC 4.8 requires a space between "" and suffix
inline nlohmann::json operator"" _json(const char* s, std::size_t n)
#endif
{
return nlohmann::json::parse(s, s + n);
}
#if defined(__cpp_char8_t)
JSON_HEDLEY_NON_NULL(1)
inline nlohmann::json operator""_json(const char8_t* s, std::size_t n)
{
return nlohmann::json::parse(reinterpret_cast<const char*>(s),
reinterpret_cast<const char*>(s) + n);
}
#endif
/// @brief user-defined string literal for JSON pointer
/// @sa https://json.nlohmann.me/api/basic_json/operator_literal_json_pointer/
JSON_HEDLEY_NON_NULL(1)
#if !defined(JSON_HEDLEY_GCC_VERSION) || JSON_HEDLEY_GCC_VERSION_CHECK(4,9,0)
inline nlohmann::json::json_pointer operator""_json_pointer(const char* s, std::size_t n)
#else
// GCC 4.8 requires a space between "" and suffix
inline nlohmann::json::json_pointer operator"" _json_pointer(const char* s, std::size_t n)
#endif
{
return nlohmann::json::json_pointer(std::string(s, n));
}
#if defined(__cpp_char8_t)
inline nlohmann::json::json_pointer operator""_json_pointer(const char8_t* s, std::size_t n)
{
return nlohmann::json::json_pointer(std::string(reinterpret_cast<const char*>(s), n));
}
#endif
} // namespace json_literals
} // namespace literals
#endif // JSON_NO_UDLS
NLOHMANN_JSON_NAMESPACE_END
///////////////////////
@@ -32689,17 +32634,6 @@ struct formatter<nlohmann::NLOHMANN_BASIC_JSON_TPL, char> // NOLINT(cert-dcl58-c
} // namespace std
#if JSON_USE_GLOBAL_UDLS && !defined(JSON_NO_UDLS)
#if !defined(JSON_HEDLEY_GCC_VERSION) || JSON_HEDLEY_GCC_VERSION_CHECK(4,9,0)
using nlohmann::literals::json_literals::operator""_json; // NOLINT(misc-unused-using-decls,google-global-names-in-headers)
using nlohmann::literals::json_literals::operator""_json_pointer; //NOLINT(misc-unused-using-decls,google-global-names-in-headers)
#else
// GCC 4.8 requires a space between "" and suffix
using nlohmann::literals::json_literals::operator"" _json; // NOLINT(misc-unused-using-decls,google-global-names-in-headers)
using nlohmann::literals::json_literals::operator"" _json_pointer; //NOLINT(misc-unused-using-decls,google-global-names-in-headers)
#endif
#endif
// #include <nlohmann/detail/macro_unscope.hpp>
// __ _____ _____ _____
// __| | __| | | | JSON for Modern C++
@@ -32728,7 +32662,6 @@ struct formatter<nlohmann::NLOHMANN_BASIC_JSON_TPL, char> // NOLINT(cert-dcl58-c
#undef JSON_INLINE_VARIABLE
#undef JSON_NO_UNIQUE_ADDRESS
#undef JSON_DISABLE_ENUM_SERIALIZATION
#undef JSON_USE_GLOBAL_UDLS
#ifndef JSON_TEST_KEEP_MACROS
#undef JSON_CATCH
@@ -32921,4 +32854,97 @@ struct formatter<nlohmann::NLOHMANN_BASIC_JSON_TPL, char> // NOLINT(cert-dcl58-c
#pragma GCC diagnostic pop
#endif
// The user-defined string literals are in a separate header, because their
// bodies instantiate the parser in every translation unit that includes them.
// Define JSON_NO_AUTOMATIC_UDLS to include <nlohmann/json_literals.hpp> only
// where needed.
#ifndef JSON_NO_AUTOMATIC_UDLS
// #include <nlohmann/json_literals.hpp>
// __ _____ _____ _____
// __| | __| | | | 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
#ifndef INCLUDE_NLOHMANN_JSON_LITERALS_HPP_
#define INCLUDE_NLOHMANN_JSON_LITERALS_HPP_
#include <cstddef> // size_t
#include <string> // string
// #include <nlohmann/json.hpp>
// This header is included at the end of <nlohmann/json.hpp> unless
// JSON_NO_AUTOMATIC_UDLS is defined, and can be included on its own after that.
// Either way, the library's internal macros are no longer defined here (and the
// amalgamation inlines macro_scope.hpp only once), so only standard and public
// macros may be used below.
NLOHMANN_JSON_NAMESPACE_BEGIN
inline namespace literals
{
inline namespace json_literals
{
/// @brief user-defined string literal for JSON values
/// @sa https://json.nlohmann.me/api/operator_literal_json/
#if !defined(__GNUC__) || defined(__clang__) || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)
inline nlohmann::json operator""_json(const char* s, std::size_t n)
#else
// GCC 4.8 requires a space between "" and suffix
inline nlohmann::json operator"" _json(const char* s, std::size_t n)
#endif
{
return nlohmann::json::parse(s, s + n);
}
#if defined(__cpp_char8_t)
inline nlohmann::json operator""_json(const char8_t* s, std::size_t n)
{
return nlohmann::json::parse(reinterpret_cast<const char*>(s),
reinterpret_cast<const char*>(s) + n);
}
#endif
/// @brief user-defined string literal for JSON pointer
/// @sa https://json.nlohmann.me/api/operator_literal_json_pointer/
#if !defined(__GNUC__) || defined(__clang__) || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)
inline nlohmann::json::json_pointer operator""_json_pointer(const char* s, std::size_t n)
#else
// GCC 4.8 requires a space between "" and suffix
inline nlohmann::json::json_pointer operator"" _json_pointer(const char* s, std::size_t n)
#endif
{
return nlohmann::json::json_pointer(std::string(s, n));
}
#if defined(__cpp_char8_t)
inline nlohmann::json::json_pointer operator""_json_pointer(const char8_t* s, std::size_t n)
{
return nlohmann::json::json_pointer(std::string(reinterpret_cast<const char*>(s), n));
}
#endif
} // namespace json_literals
} // namespace literals
NLOHMANN_JSON_NAMESPACE_END
#if !defined(JSON_USE_GLOBAL_UDLS) || JSON_USE_GLOBAL_UDLS
#if !defined(__GNUC__) || defined(__clang__) || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)
using nlohmann::literals::json_literals::operator""_json; // NOLINT(misc-unused-using-decls,google-global-names-in-headers)
using nlohmann::literals::json_literals::operator""_json_pointer; //NOLINT(misc-unused-using-decls,google-global-names-in-headers)
#else
// GCC 4.8 requires a space between "" and suffix
using nlohmann::literals::json_literals::operator"" _json; // NOLINT(misc-unused-using-decls,google-global-names-in-headers)
using nlohmann::literals::json_literals::operator"" _json_pointer; //NOLINT(misc-unused-using-decls,google-global-names-in-headers)
#endif
#endif
#endif // INCLUDE_NLOHMANN_JSON_LITERALS_HPP_
#endif
#endif // INCLUDE_NLOHMANN_JSON_HPP_
+83
View File
@@ -0,0 +1,83 @@
// __ _____ _____ _____
// __| | __| | | | 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
#ifndef INCLUDE_NLOHMANN_JSON_LITERALS_HPP_
#define INCLUDE_NLOHMANN_JSON_LITERALS_HPP_
#include <cstddef> // size_t
#include <string> // string
#include <nlohmann/json.hpp>
// This header is included at the end of <nlohmann/json.hpp> unless
// JSON_NO_AUTOMATIC_UDLS is defined, and can be included on its own after that.
// Either way, the library's internal macros are no longer defined here (and the
// amalgamation inlines macro_scope.hpp only once), so only standard and public
// macros may be used below.
NLOHMANN_JSON_NAMESPACE_BEGIN
inline namespace literals
{
inline namespace json_literals
{
/// @brief user-defined string literal for JSON values
/// @sa https://json.nlohmann.me/api/operator_literal_json/
#if !defined(__GNUC__) || defined(__clang__) || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)
inline nlohmann::json operator""_json(const char* s, std::size_t n)
#else
// GCC 4.8 requires a space between "" and suffix
inline nlohmann::json operator"" _json(const char* s, std::size_t n)
#endif
{
return nlohmann::json::parse(s, s + n);
}
#if defined(__cpp_char8_t)
inline nlohmann::json operator""_json(const char8_t* s, std::size_t n)
{
return nlohmann::json::parse(reinterpret_cast<const char*>(s),
reinterpret_cast<const char*>(s) + n);
}
#endif
/// @brief user-defined string literal for JSON pointer
/// @sa https://json.nlohmann.me/api/operator_literal_json_pointer/
#if !defined(__GNUC__) || defined(__clang__) || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)
inline nlohmann::json::json_pointer operator""_json_pointer(const char* s, std::size_t n)
#else
// GCC 4.8 requires a space between "" and suffix
inline nlohmann::json::json_pointer operator"" _json_pointer(const char* s, std::size_t n)
#endif
{
return nlohmann::json::json_pointer(std::string(s, n));
}
#if defined(__cpp_char8_t)
inline nlohmann::json::json_pointer operator""_json_pointer(const char8_t* s, std::size_t n)
{
return nlohmann::json::json_pointer(std::string(reinterpret_cast<const char*>(s), n));
}
#endif
} // namespace json_literals
} // namespace literals
NLOHMANN_JSON_NAMESPACE_END
#if !defined(JSON_USE_GLOBAL_UDLS) || JSON_USE_GLOBAL_UDLS
#if !defined(__GNUC__) || defined(__clang__) || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)
using nlohmann::literals::json_literals::operator""_json; // NOLINT(misc-unused-using-decls,google-global-names-in-headers)
using nlohmann::literals::json_literals::operator""_json_pointer; //NOLINT(misc-unused-using-decls,google-global-names-in-headers)
#else
// GCC 4.8 requires a space between "" and suffix
using nlohmann::literals::json_literals::operator"" _json; // NOLINT(misc-unused-using-decls,google-global-names-in-headers)
using nlohmann::literals::json_literals::operator"" _json_pointer; //NOLINT(misc-unused-using-decls,google-global-names-in-headers)
#endif
#endif
#endif // INCLUDE_NLOHMANN_JSON_LITERALS_HPP_
+1 -2
View File
@@ -18,6 +18,7 @@ module;
// See: https://github.com/nlohmann/json/issues/5103
#include <nlohmann/json.hpp>
#include <nlohmann/json_literals.hpp>
export module nlohmann.json;
@@ -32,7 +33,6 @@ using NLOHMANN_JSON_NAMESPACE::ordered_json;
using NLOHMANN_JSON_NAMESPACE::ordered_map;
using NLOHMANN_JSON_NAMESPACE::to_string;
#ifndef JSON_NO_UDLS
inline namespace literals
{
inline namespace json_literals
@@ -41,7 +41,6 @@ inline namespace json_literals
using NLOHMANN_JSON_NAMESPACE::literals::json_literals::operator""_json_pointer;
} // namespace json_literals
} // namespace literals
#endif
// Note: the following nlohmann::detail symbols must be exported due to
// an MSVC bug failing to compile without these symbols visible (ticket #3970)
@@ -6,10 +6,12 @@
// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
// SPDX-License-Identifier: MIT
// This translation unit checks JSON_NO_UDLS, which leaves out the user-defined
// string literals operator""_json and operator""_json_pointer entirely (see
// #5294), while the rest of the library keeps working.
#define JSON_NO_UDLS 1
// This translation unit checks JSON_NO_AUTOMATIC_UDLS, which keeps
// <nlohmann/json.hpp> from including <nlohmann/json_literals.hpp> and thereby
// leaves out the user-defined string literals operator""_json and
// operator""_json_pointer (see #5294), and that including
// <nlohmann/json_literals.hpp> afterwards brings them back.
#define JSON_NO_AUTOMATIC_UDLS 1
#include "doctest_compatibility.h"
@@ -23,7 +25,7 @@ using json = nlohmann::json;
// argument-dependent lookup of a literal operator called by its function name
// also searches the inline namespaces nlohmann::literals::json_literals.
NLOHMANN_JSON_NAMESPACE_BEGIN
struct no_udls_probe
struct no_automatic_udls_probe
{
operator const char* () const // NOLINT(google-explicit-constructor,hicpp-explicit-conversions)
{
@@ -52,7 +54,7 @@ template<typename T>
using has_json_pointer_udl = nlohmann::detail::is_detected<json_pointer_udl_t, T>;
} // namespace
TEST_CASE("JSON_NO_UDLS")
TEST_CASE("JSON_NO_AUTOMATIC_UDLS")
{
SECTION("literals are not declared")
{
@@ -61,8 +63,8 @@ TEST_CASE("JSON_NO_UDLS")
CHECK_FALSE(has_json_pointer_udl<const char*>::value);
// nlohmann::literals::json_literals
CHECK_FALSE(has_json_udl<nlohmann::no_udls_probe>::value);
CHECK_FALSE(has_json_pointer_udl<nlohmann::no_udls_probe>::value);
CHECK_FALSE(has_json_udl<nlohmann::no_automatic_udls_probe>::value);
CHECK_FALSE(has_json_pointer_udl<nlohmann::no_automatic_udls_probe>::value);
}
SECTION("the rest of the library keeps working")
@@ -75,3 +77,21 @@ TEST_CASE("JSON_NO_UDLS")
CHECK(j.contains(ptr));
}
}
// the literals can still be added where they are needed
#include <nlohmann/json_literals.hpp>
TEST_CASE("JSON_NO_AUTOMATIC_UDLS with <nlohmann/json_literals.hpp>")
{
SECTION("global namespace")
{
CHECK("[1,2]"_json == json({1, 2}));
CHECK("/a/0"_json_pointer == json::json_pointer("/a/0"));
}
SECTION("nlohmann::literals::json_literals")
{
using namespace nlohmann::literals::json_literals; // NOLINT(google-build-using-namespace)
CHECK(R"({"a":[42]})"_json.at("/a/0"_json_pointer) == 42);
}
}