* fix: treat single-element brace-init as copy/move
When passing a json value using brace initialization with a single element
(e.g., `json j{someObj}` or `foo({someJson})`), C++ always prefers the
initializer_list constructor over the copy/move constructor. This caused
the value to be unexpectedly wrapped in a single-element array.
This bug was previously compiler-dependent (GCC wrapped, Clang did not),
but Clang 20 started matching GCC behavior, making it a universal issue.
Fix: In the initializer_list constructor, when type deduction is enabled
and the list has exactly one element, copy/move it directly instead of
creating a single-element array.
Before:
json obj = {{"key", 1}};
json j{obj}; // -> [{"key":1}] (wrong: array)
foo({obj}); // -> [{"key":1}] (wrong: array)
After:
json j{obj}; // -> {"key":1} (correct: copy)
foo({obj}); // -> {"key":1} (correct: copy)
To explicitly create a single-element array, use json::array({value}).
Fixes the issue #5074
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* fix: regenerate amalgamated single_include/nlohmann/json.hpp
- Add missing comment from include/nlohmann/json.hpp explaining the
single-element brace-init fix (issue #5074)
- Fix extra 4-space indentation in embedded json_fwd.hpp section
Regenerated by running: make amalgamate
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* Revert brace-init semantics change and fix amalgamation
The single-element brace-init change was a breaking change that cannot be accepted upstream. Reverted all related source, test, and doc changes, then regenerated single_include with correct indentation to pass the amalgamation CI check.
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* Fix: add JSON_BRACE_INIT_COPY_SEMANTICS opt-in macro for issue #5074
Single-element brace initialization wrapping in an array cannot be fixed without breaking existing code. Added JSON_BRACE_INIT_COPY_SEMANTICS as an opt-in macro (default 0) so users can enable copy/move semantics for single-element brace init without affecting anyone relying on the current behavior.
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* docs: add dedicated macro page and CI test target for JSON_BRACE_INIT_COPY_SEMANTICS
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* fix: remove compiler-dependent assertions from #5074 regression test
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* fix: use defined() guard for JSON_BRACE_INIT_COPY_SEMANTICS to satisfy -Wundef
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* docs: fix section name in json_brace_init_copy_semantics.md to pass style check
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* docs: move Default definition section before Notes to fix style check order
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
---------
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* Make std::filesystem::path conversion to/from UTF-8 encoded JSON string explicit.
Signed-off-by: Richard Musil <risa2000x@gmail.com>
* Experimental: Changing C++ standard detection logic to accommodate potential corner cases.
Signed-off-by: Richard Musil <risa2000x@gmail.com>
* Drop C++ standard tests for compilers which do not implement required features.
Signed-off-by: Richard Musil <risa2000x@gmail.com>
* Drop C++ standard tests for MSVC versions which do not implement required features.
Signed-off-by: Richard Musil <risa2000x@gmail.com>
---------
Signed-off-by: Richard Musil <risa2000x@gmail.com>
Co-authored-by: Richard Musil <risa2000x@gmail.com>
* Support any basic_json type in NLOHMANN_DEFINE_TYPE_* macros
Signed-off-by: kimci86 <kimci86@hotmail.fr>
* Test NLOHMANN_DEFINE_TYPE_* macros also support unordered_json
Signed-off-by: kimci86 <kimci86@hotmail.fr>
* Simplify test about NLOHMANN_DEFINE_TYPE_ with many arguments
Signed-off-by: kimci86 <kimci86@hotmail.fr>
* Remove extra scope in macros tests
Signed-off-by: kimci86 <kimci86@hotmail.fr>
* Remove unused test class in macros tests
Signed-off-by: kimci86 <kimci86@hotmail.fr>
* Update documentation about NLOHMANN_DEFINE_TYPE_* macros
Signed-off-by: kimci86 <kimci86@hotmail.fr>
* Fix NLOHMANN_JSON_SERIALIZE_ENUM documentation
Signed-off-by: kimci86 <kimci86@hotmail.fr>
* Mark some variables const in macros tests, fixes clang-tidy
Signed-off-by: kimci86 <kimci86@hotmail.fr>
* Workaround clang 3.5 issue with const object initialization
Signed-off-by: kimci86 <kimci86@hotmail.fr>
* Update highlighted lines in NLOHMANN_DEFINE_TYPE_* macros examples
Signed-off-by: kimci86 <kimci86@hotmail.fr>
* Fix swapped macros in documentation
Signed-off-by: kimci86 <kimci86@hotmail.fr>
* Remove extra backslashes at the end of macros
Signed-off-by: kimci86 <kimci86@hotmail.fr>
* Require basic_json type in NLOHMANN_DEFINE_TYPE_* generated functions
Signed-off-by: kimci86 <kimci86@hotmail.fr>
* Fix typos in macros documentation
Signed-off-by: kimci86 <kimci86@hotmail.fr>
---------
Signed-off-by: kimci86 <kimci86@hotmail.fr>
* change NLOHMANN_JSON_FROM_WITH_DEFAULT to let NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT work with an empty JSON instance
* fix ci_static_analysis_clang (ci_clang_tidy)
* change NLOHMANN_JSON_FROM_WITH_DEFAULT to let NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT work with an empty JSON instance
* Move UDLs into nlohmann::literals::json_literals namespace
* Add 'using namespace' to unit tests
* Add 'using namespace' to examples
* Add 'using namespace' to README
* Move UDL mkdocs pages out of basic_json/
* Update documentation
* Update docset index
* Add JSON_GlobalUDLs CMake option
* Add unit test
* Build examples without global UDLs
* Add CI target
* Add versioned inline namespace
Add a versioned inline namespace to prevent ABI issues when linking code
using multiple library versions.
* Add namespace macros
* Encode ABI information in inline namespace
Add _diag suffix to inline namespace if JSON_DIAGNOSTICS is enabled, and
_ldvcmp suffix if JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON is enabled.
* Move ABI-affecting macros into abi_macros.hpp
* Move std_fs namespace definition into std_fs.hpp
* Remove std_fs namespace from unit test
* Format more files in tests directory
* Add unit tests
* Update documentation
* Fix GDB pretty printer
* fixup! Add namespace macros
* Derive ABI prefix from NLOHMANN_JSON_VERSION_*
* Add C++20 3-way comparison operator and fix broken comparisons
Fixes#3207.
Fixes#3409.
* Fix iterators to meet (more) std::ranges requirements
Fixes#3130.
Related discussion: #3408
* Add note about CMake standard version selection to unit tests
Document how CMake chooses which C++ standard version to use when
building tests.
* Update documentation
* CI: add legacy discarded value comparison
* Fix internal linkage errors when building a module
* Add key_compare member to ordered_map
* Replace == with key_compare in ordered_map
* Expose the actual comparison function used by object_t
nlohmann::ordered_map uses a different comparison function than the one
provided via template parameter.
* Introduce a type trait to detect if object_t has a key_compare member.
* Rename object_comparator_t to default_object_comparator_t.
* Add object_comparator_t to be conditionally defined as
object_t::key_compare, if available, or default_object_comparator_t
otherwise.
* Update the documentation accordingly.
Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>
* Add type traits to check if a type is usable as object key
Add type trait to check:
* if a type is a specialization of a template.
* if a type is a json_pointer.
* if a type is a basic_json::{const_,}iterator.
* if two types are comparable using a given comparison functor.
* if a type is comparable to basic_json::object_t::key_type.
* if a type has a member type is_transparent.
* if a type is usable as object key.
* if a type has an erase() function accepting a given KeyType.
Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>
* Rework basic_json element access to accept more key types
Rework basic_json element access member functions and operators to
accept any type that meets the requirements defined by type trait
detail::is_usable_as_key_type.
Member functions and operators:
* at()
* operator[]
* value()
* erase()
* find()
* count()
* contains()
Update documentation to reflect these changes.
Add unit tests to excercise the new functions using std::string_view.
Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>
Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>
* Refactor unit test creation
Add functions for creating tests and to supply test- and
standard-specific build settings.
Raises minimum CMake version to 3.13 in test directory.
json_test_add_test_for(
<file>
MAIN <main>
[CXX_STANDARDS <version_number>...] [FORCE])
Given a <file> unit-foo.cpp, produces
test-foo_cpp<version_number>
if C++ standard <version_number> is supported by the compiler and
thesource file contains JSON_HAS_CPP_<version_number>. Use FORCE to
create the test regardless of the file containing
JSON_HAS_CPP_<version_number>. Test targets are linked against <main>.
CXX_STANDARDS defaults to "11".
json_test_set_test_options(
all|<tests>
[CXX_STANDARDS all|<args>...]
[COMPILE_DEFINITIONS <args>...]
[COMPILE_FEATURES <args>...]
[COMPILE_OPTIONS <args>...]
[LINK_LIBRARIES <args>...]
[LINK_OPTIONS <args>...])
Supply test- and standard-specific build settings.
Specify multiple tests using a list e.g., "test-foo;test-bar".
Must be called BEFORE the test is created.
* Use CMAKE_MODULE_PATH
* Don't undef some macros if JSON_TEST_KEEP_MACROS is defined
* Use JSON_TEST_KEEP_MACROS
Incidentally enables the regression tests for #2546 and #3070.
A CHECK_THROWS_WITH_AS in #3070 was disabled which is tracked in #3377
and a line in from_json(..., std_fs::path&) was marked with LCOV_EXCL_LINE.
* Add three-way comparison feature test macro
* Disable broken comparison if JSON_HAS_THREE_WAY_COMPARISON
* Fix redefinition of inline constexpr statics
Redelcaration of inline constexpr static data members in namespace scope
was deprecated in C++17. Fixes -Werror=deprecated compilation failures.
* Fix more test build failures due to missing noexcept
* CI: update cmake_flags test to use CMake 3.13 in test directory
Also change default for JSON_BuildTests option to depend on CMake
version.
* CI: turn *_CXXFLAGS into CMake lists
* CI: use JSON_TestStandards to set CXX_STANDARD
* CI: pass extra CXXFLAGS to standards tests
* Added new macros NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT.
* Updated docs for NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT accordingly
* Rephrased docs for NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT
* Updated docs for NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT
* Renamed default_obj in to avoid name clashes
* Added test for serialization of default constructed object
* Add const to getters for macro tests
Co-authored-by: Chaoya Li <harry75369@gmail.com>
The previous version relied on the existence of an 'iterator' type.
As mentioned in comments, this is not the proper way to do it and
causes issues with certain types (e.g. views from range-v3).
Add a 'is_range' trait that properly detects the return type of
'begin'/'end', and use it in instead.
SamareshSingh
Niels Lohmann
NmPassTHFan
risa2000
kimci86
Nikhil
Nissim Armand Ben Danan
Einars Netlis-Galejs
Niccolò Iardella
Vyacheslav Zhdanovskiy
alferov
Raphael Grimm
Florian Albrechtskirchinger
Richard Hozák
pketelsen
Giovanni Cerretani
Niels Lohmann
Théo DELRIEU
Giovanni Cerretani
David Pfahler
Jonas Wittbrodt