* Reserve capacity in from_json() object conversion when supported
The object-to-container from_json() overload filled the target
container one element at a time without reserving capacity, even
when the target type supports reserve() (e.g. std::unordered_map)
and the number of elements is already known. This caused unnecessary
rehashing while parsing large objects into such containers.
Add a reserve-detecting overload (from_json_object_impl), mirroring
the priority_tag-based SFINAE technique already used by the array
conversion path (from_json_array_impl), so that reserve(size()) is
called up front when available and the loop falls back unchanged
otherwise (e.g. for std::map).
Fixes#5406
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Update doc example outputs for new object-conversion iteration order
Reserving capacity in from_json()'s object-conversion path before
inserting elements changes libstdc++'s std::unordered_map bucket
layout, which changes the iteration order used by
get__ValueType_const.cpp, get_to.cpp and operator__ValueType.cpp to
print the elements of a converted std::unordered_map<std::string,
json>. Verified against a clean develop checkout (built with the
same GCC/libstdc++ used in CI) that the old order was produced
without this PR's change and the new order is produced with it, and
that the three affected examples now match their updated expected
output byte-for-byte.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Factor out a reserve-dispatch helper instead of duplicating the object from_json loop
Addresses review feedback from @gregmarr on PR #5472: the emplace loop no
longer needs to exist twice for the reserve/no-reserve cases. A small
from_json_object_reserve() overload pair (SFINAE-dispatched on whether
reserve() exists, mirroring the priority_tag technique used elsewhere)
either calls reserve() or is a no-op; from_json_object_impl() calls it once.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Inline from_json_object_impl into from_json now that it is called only once
Addresses review feedback from @gregmarr on PR #5472: with the reserve
loop de-duplicated, from_json_object_impl no longer needs to be a
separate function that from_json immediately delegates to.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---------
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* 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>
* Guard JSON_HEDLEY_DIAGNOSTIC_PUSH/POP with the same compiler check as the pragma they bracket
Addresses review feedback from @gregmarr on PR #5485: the push/pop calls
were unconditional, so compilers other than the one the ignored-pragma
targets (e.g. MSVC, or GCC where the pair only applies under __clang__)
now did a needless push/pop with nothing suppressed in between. Move the
existing #ifdef __GNUC__ / #if defined(__clang__) guard to also cover the
push/pop, restoring the original zero-overhead behavior on other compilers
while still emitting the pragma itself through Hedley.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---------
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Fix discussion #4209: custom BinaryType direct assignment and extraction
When a custom BinaryType is configured (other than the default std::vector<uint8_t>),
users can now:
1. Assign values of that type directly to create binary values (not arrays)
2. Extract binary values back to that type with get<>()
3. Extract arrays to that type (for backward compatibility)
Implementation:
- Add is_compatible_binary_type trait to centralize SFINAE condition
- Update to_json to accept custom BinaryType values directly
- Update from_json to handle both binary and array inputs for custom BinaryType
- Add #include <vector> with IWYU comment to from_json.hpp
- Add comprehensive tests for assignment and array extraction
- Update binary_t documentation with example
This is purely additive and invisible to the default nlohmann::json alias, which
continues to treat std::vector<uint8_t> as arrays.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Fix CI: missing include and const-correctness
- Add #include <vector> to type_traits.hpp for the new
is_compatible_binary_type trait's std::vector<std::uint8_t> reference
(caught by cpplint's include-what-you-use check)
- Mark test-local json variables const where never reassigned
(caught by clang-tidy's misc-const-correctness check)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---------
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Fix compile error when using nlohmann ordered_map with WITH_DEFAULT macros
ordered_map inherits its copy and move assignment from the underlying std vector, which requires value_type to be CopyAssignable. value_type is pair<const Key, T> whose assignment is deleted because of the const Key, so any code that assigns ordered_map (for example the ternary in NLOHMANN_JSON_FROM_WITH_DEFAULT) fails to compile (issue #5122). Provide assignment operators on ordered_map that rebuild via clear plus push_back for copy and transfer the underlying buffer for move, neither of which needs pair assignment. Also switch the map-shaped from_json overload from a transform plus inserter idiom to a range-for plus emplace, which avoids the same hazard.
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* Update ordered_map.hpp
removed unwanted comments
Signed-off-by: SamareshSingh <97642706+ssam18@users.noreply.github.com>
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* Update json.hpp
Signed-off-by: SamareshSingh <97642706+ssam18@users.noreply.github.com>
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* Address CI issues for ordered_map fix
Declare an explicit defaulted destructor on ordered_map so the rule of five is complete (clang-tidy cppcoreguidelines-special-member-functions and hicpp-special-member-functions). Initialize the ordered_map field in the regression test struct so GCC effective-C++ stops flagging Example_5122 with a missing member initializer.
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* Suppress redundant-member-init lint on Example_5122::c
The empty brace-init on c{} is required by GCC -Weffc++ to mark the member as initialized in the synthesized default constructor, but clang-tidy readability-redundant-member-init flags the same line because ordered_map already has a default constructor. The two checks pull in opposite directions, so add a targeted NOLINT to keep both happy.
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* Address review: strong exception safety in copy-assign, simplify move-assign noexcept
Copy assignment now constructs a temporary copy before move-assigning the
Container subobject, preserving *this if the copy throws. Move assignment
uses std::is_nothrow_move_assignable<Container> for a cleaner noexcept
specifier, matching the style of the move constructor.
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* Restore self-assignment check in copy-assign to satisfy cert-oop54-cpp
clang-tidy's cert-oop54-cpp flagged the previous revision because it could
not recognize the implicit self-safety of the copy-then-move pattern.
Restore the explicit `if (this != &other)` guard — strong exception safety
is preserved since the temporary copy is still constructed before the
move-assign of the Container subobject.
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* Address review: add explicit self-assignment and move-assignment tests for ordered_map
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* Address review: gate -Wself-assign-overloaded suppression on Clang version
-Wself-assign-overloaded was introduced in Clang 7. Older Clang versions fail the build with "unknown warning group" when the suppression pragma references it unconditionally. Use __has_warning inside an __clang__ branch so the suppression is only emitted on Clang versions that recognize the warning. The inner check stays inside the __clang__ guard because GCC does not provide __has_warning and would tokenize-error on the argument list.
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* Address CI: drop unused gating macro to silence -Wunused-macros
The previous attempt defined JSON_TEST_5122_SUPPRESS_SELF_ASSIGN_OVERLOADED
as 0 unconditionally and then overrode it to 1 on Clang versions that recognize the warning. On those Clangs the initial define is immediately
undef'd without being read, which trips Clang's -Wunused-macros under -Weverything in the ci_test_clang job. Drop the macro and gate the
DOCTEST_CLANG_SUPPRESS_WARNING_PUSH/POP pragmas directly with __has_warning inside the existing __clang__ branch.
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
---------
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
Signed-off-by: SamareshSingh <97642706+ssam18@users.noreply.github.com>
* Add reference handling to tuples
Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>
* Remove template template type because pair isn't working
Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>
* amalgamate std::tie changes
Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>
* allow the elation of a move by removing the ref requirement
Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>
* force all number_xxx_t to be interchangeable
Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>
* Finally got amalgamate to work correctly
Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>
* remove const version, add a test case for scrambled number representations.
Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>
* Use the logical set of requirements instead of decltype because VS 2015 doesn't like it
Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>
---------
Signed-off-by: Evelyn LePain <ava.lepain@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>
* 🚧 conversions for std::optional
* 🏁 fix <optional> inclusion
* 💚 overwork tests
* Use JSON_HAS_CPP_17 only after it has been defined
* ✅ update tests
* 🏁 include right <optional> header
* ♻️ do not include experimental headers
* Add missing #endif after rebase
* Fix failing test
* Only define conversion to std::optional when JSON_USE_IMPLICIT_CONVERSION is disabled.
* missing endif
* Remove Wfloat-equal suppress
* amalgamate
* Move include of optional out of macro_scope; probably does not make sense to be there
* Make clang-tidy happy
* Suppress lint instead of changing to 'contains'
---------
Co-authored-by: Niels Lohmann <mail@nlohmann.me>
Co-authored-by: Markus Palonen <markus.palonen@gmail.com>
* Enhance the UDT unit test to expose the issue
Add a new enum type with uint64_t as the underlying type.
Use it in the overall UDT. Not strictly needed, but it helps exercise its expected usage.
Create an object of this enum type with a large value (negative if cast to int64_t).
Perform several checks on this object as converted to `json`, which fail without the fix.
* Fix the issue in the relevant `to_json` overload.
Select the correct json type depending on the signedness of the enum's underlying type.
This fixes the new checks in the unit test.
* Add the fix to the single_include
I ran `make pretty` but that modified 20 files, performing a significant amount of indentation changes, none of them related to my change.
I ran `make amalgamate`, but that did nothing. Apparently, the make rule won't run if the single_include files have already been updated by `make pretty`.
I forced `make amalgamate` to do the work by touching the file with the fix.
I then decided to keep just the minimal needed change: the addition of the fix to the single_include file.
I just am not conversant enough in Linux to know whether I installed astyle correctly (had to clone the source from a beta branch and build, in order to get support for `--squeeze-lines`).
* Resolve CI errors and use qualified `std::uint64_t`
The fix was relying on implicit conversions in the non-taken branch.
- Ordinarily (work on a C++20 codebase) I would have used `if constexpr` here, sidestepping the issue, but that's not available on C++11 so I didn't bother.
- So instead of an `if` statement, I used a compile-time constant to select the correct overload.
- This is arguably better in this case, anyway.
I was using function-style casts for typed constants, which I consider superior for constants, but the CI checks disagree, so changed all to `static_cast`.
- For some reason, the CI checks didn't point at all of them, so I hope I caught them all myself.
Built with clang14 and all unit tests pass.
---------
Co-authored-by: Juan Carlos Arevalo Baeza (JCAB) <jcab@ntdev.microsoft.com>
* 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
* Make exception context optional
Change exception context parameter to pointer and replace context with
nullptr where appropriate.
* Support escaping other string types
* Add string concatenation function
Add variadic concat() function for concatenating char *, char, and
string types.
* Replace string concatenations using + with concat()
* Template json_pointer on string type
Change json_pointer from being templated on basic_json to being
templated on string type.
* Add unit test for #3388Closes#3388.
* Fix regression test for #2958
* Add backwards compatibility with json_pointer<basic_json>
* Update json_pointer docs
* Allow comparing different json_pointers
* Update version numbers
Constrain from_json() overload for StringType to not accept json_ref and
require it to be assignable, instead of constructible, from
basic_json::string_t.
Re-enable C++14 tests on Clang <4.0.
Fixes#3171.
Fixes#3267.
Fixes#3312.
Fixes#3384.
Restore the previously disabled check for regression #3070 on all
compilers but MSVC.
To summarize the issue:
Given namespace fs = std::filesystem.
On MSVC attempting to construct an fs::path from json results in an
ambiguous overload resolution because fs::path can be constructed from
both a std::string as well as another fs::path.
To the best of my knowledge there is no way to fix an ambiguous overload
situation involving a type we do not control and with json implicitly
converting to both std::string and fs::path.
Re-enabling the check where it compiles and keeping it disabled for MSVC
is the best we can do.
Closes#3377 and #3382.
* 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
* meta: rework is_compatible/is_constructible_string_type
These type traits performed an incorrect and insufficient check.
Converting to a std::filesystem::path used to work by accident thanks to
these brittle constraints, but the clean-up performed in #3020 broke them.
* support std::filesystem::path
Fixes#3070
Niels Lohmann
Federico Sfriso
Cosmin D.
SamareshSingh
EALePain
Sergiu Deitsch
risa2000andRichard Musil
Michael Valladolid
peng-wang-cn
Juan Carlos Arevalo BaezaandJuan Carlos Arevalo Baeza
Raphael Grimmandbarcode
Florian Albrechtskirchinger
Richard Hozák
Niels Lohmann
Théo DELRIEU
Pierre Hallot
Ferry Huberts