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168aa3723c8286f69e6fef41508ee996f985fc3e
json/include/nlohmann/detail/conversions/to_json.hpp
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Niels Lohmann e5a89d671f Fix lint debt: enum-macro NOLINTs, doctest as SYSTEM, no-op analyzer (#5737) 
* Drop stale LCOV_EXCL_LINE from the json_pointer out_of_range.410 throw

The comment said the size_type overflow check in array_index() is only
triggered on special platforms like 32-bit, and the throw was excluded
from coverage. On 64-bit platforms the check is true for SIZE_MAX
itself, and unit-json_pointer.cpp has asserted that case four times
since #5395, so the line is executed in the coverage job. Reword the
comment and remove the exclusion marker so the coverage report notices
if the tests stop reaching it.

Part of #5725

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

* Name all three C-array check aliases in the enum-macro NOLINTs

NLOHMANN_JSON_SERIALIZE_ENUM(_STRICT) suppressed the c-array warning
under modernize-avoid-c-arrays only, but clang-tidy emits the same
diagnostic under the aliases cppcoreguidelines-avoid-c-arrays and
hicpp-avoid-c-arrays too. Any user running those checks got a false
positive at every macro expansion, and our own tests needed a local
NOLINT at each call site to work around it.

Name all three aliases in the four macro comments instead, and drop
the now-redundant c-array names from the five test call-site NOLINTs.
Comment-only change; behavior, the public API, and the ABI do not
change. Ran make amalgamate.

Part of #5725

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

* Include doctest as a SYSTEM directory instead of disabling warnings for all tests

test_main added -Wno-deprecated and -Wno-float-equal as PUBLIC compile
options for every non-MSVC compiler, so they were applied to every
translation unit, library headers included, and silenced the CI
warnings meant to check the library's own -Wfloat-equal pragmas. The
only code that actually needed the suppression was the vendored
doctest.h, which was included as a normal (non-SYSTEM) directory.

Include thirdparty/doctest as SYSTEM for test_main, matching what
tests/abi/CMakeLists.txt already does, and drop the two suppressions
from both targets. Verified locally that unit-comparison,
unit-conversions and unit-constructor1 compile clean with
-Werror -Weverything and doctest as -isystem, and that CMake still
configures with JSON_BuildTests=ON.

Part of #5725

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

* Remove the no-op ci_clang_analyze target

ci_clang_analyze configured the build with the real compiler and only
then wrapped ninja with scan-build. scan-build intercepts compiles by
overriding CC/CXX, but build.ninja already had the compiler path baked
in from the configure step, so every run bypassed the analyzer: CI
logs show "No bugs found" after a normal build, never an analysis.
The job also used Debian's frozen clang-tools-14 rather than the
image's own clang, and CLANG_ANALYZER_CHECKS still named three
valist.* checkers that current clang merged into security.VAList.

ci_clang_tidy already runs every clang-analyzer-* check (via
.clang-tidy's "Checks: '*'") with warnings as errors, so nothing is
lost by removing the dead job. Delete ci_clang_analyze,
CLANG_ANALYZER_CHECKS and the SCAN_BUILD_TOOL lookup from
cmake/ci.cmake, drop it from the ubuntu.yml ci_static_analysis_clang
matrix, and drop the now-unused clang-tools apt package (iwyu stays
for ci_single_binaries). Reword quality_assurance.md and
assurance_case.md, which described the dead job as a working control,
to say the Clang Static Analyzer checks run through clang-tidy.

Verified that `cmake -DJSON_CI=ON` still configures cleanly and that
ci_clang_analyze no longer appears in the generated build or in any
CMake/workflow file.

Part of #5725

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

* Re-enable portability-template-virtual-member-function; remove redundant forwards

.clang-tidy disabled three checks "to get the CI going" (#4489,
2024-11-13): portability-template-virtual-member-function,
bugprone-use-after-move and its alias hicpp-invalid-access-moved.

portability-template-virtual-member-function only flagged
output_stream_adapter::write_character/write_characters; annotate
both with NOLINT and re-enable the check.

bugprone-use-after-move flagged several double forwards that have no
effect at runtime:
- from_json.hpp calls std::forward<BasicJsonType>(j).at(Idx) inside
  pack expansions; at() has no ref-qualified overloads and always
  returns an lvalue reference, so the forward is a no-op. Replace with
  plain j.at(Idx) in all four places.
- the move constructor forwards the whole object to its base class
  and then reads other's members. That is item 9 of #5724 (together
  with its cppcheck suppressions) and is left to that change.
- input_adapters.hpp forwards the container twice on purpose, so the
  begin/end iterator types match adapter_type; annotate with NOLINT
  and a comment instead of changing behavior.

The check still flags the move constructor (see above) and two sites
in at(KeyType&&) (both overloads, json.hpp, in the throw's
string_t(std::forward<KeyType>(key)) after
find(std::forward<KeyType>(key))). Open PR #5689 rewrites that hunk,
so bugprone-use-after-move (and hicpp-invalid-access-moved)
stay disabled for now, with a comment explaining why; re-enable them
once #5689 and the #5724 move-constructor change have landed.

Also resolve the portability-avoid-pragma-once TODO: single_include
never has #pragma once (amalgamate.py strips it) and every supported
compiler accepts it in include/, so keep it disabled with an
explanatory comment instead of a TODO. Fix the stale "json.hpp,
around line 1265" comment in unit-class_parser.cpp, which now points
at the move constructor's actual line.

Behavior, the public API and the ABI do not change. Verified with
clang-tidy 22.1.8 that portability-template-virtual-member-function
now reports nothing, that bugprone-use-after-move/
hicpp-invalid-access-moved report only the known at(KeyType&&) and
move-constructor sites, and that unit-custom-base-class, unit-constructor1,
unit-conversions, unit-element_access2, unit-class_parser and
unit-diagnostic-positions (JSON_DIAGNOSTIC_POSITIONS=1) compile
under ASan/UBSan and pass with the same assertion counts as before.
Ran make amalgamate.

Part of #5725

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

* Fix stale and malformed NOLINT comments

json_sax.hpp named "-warnings-as-errors" in the NOLINT list on the two
JSON_ASSERT(false) lines; that is the suffix clang-tidy appends to a
diagnostic tag under WarningsAsErrors, not a check name, and every
other JSON_ASSERT(false) omits it.

unit-capacity.cpp carried 30 "// NOLINT(misc-const-correctness)"
comments on "json j = ...;" declarations that are all used with
non-const members afterwards, so the check has nothing to report
there.

unit-constructor2.cpp used a blanket "// NOLINT: access after move is
OK here" on a use-after-move that hides every check on the line;
naming bugprone-use-after-move and hicpp-invalid-access-moved keeps
the intent once those checks are re-enabled (#5724).

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

#5725 item 10

* Remove stale .clang-tidy entries

-google-runtime-references disabled a check that neither clang-tidy
22.1.8 nor 23.1.2 lists under --list-checks -checks='*'; it was
removed upstream. The commented-out HeaderFilterRegex line has been
unused since the active HeaderFilterRegex was introduced in #2561
(2021).

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

#5725 item 11

* Remove the GCC C++20 -Wignored-attributes pragma in json.hpp

The pragma (added in #5164) claimed to work around the C++ modules
redefinition errors of #5103, but #5103 is about hard errors (e.g.
"redefinition of std::__is_constant_evaluated()", conflicting
std::integral_constant) that ignoring a warning cannot suppress; they
are traced to GCC PR 124430 and reproduce with <map> or <string>
instead of json.hpp too. A GCC 16.2 -std=gnu++20 -fmodules build
following #5103's repro steps still fails with the pragma in place,
and a build of all test TUs with GCC_CXXFLAGS (which enable
-Wignored-attributes) and the pragma removed produces no such
warning. The block only hid a warning class from GCC C++20 users
while suggesting #5103 was handled.

Overlaps #5610, whose hunks touch the closing half of this pragma to
insert the json_literals.hpp include.

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

#5725 item 9

* Fix stale doxygen comments hidden by the -Wdocumentation pragma

macro_scope.hpp ignores -Wdocumentation and -Wdocumentation-unknown-command
for the whole library, which also hides genuine documentation mistakes:

- detail::unescape() documented "@return unescaped string" but returns
  void and unescapes its argument in place; reworded to
  "@param[in,out] s string to unescape in place" and dropped the
  bogus @return.
- basic_json::get()'s copy-conversion overload wrote "converted to
  @tparam ValueType" inside @return, which Doxygen and Clang parse as
  a second, malformed @tparam; changed to "@a ValueType", matching the
  two other get() overloads a few lines above that already use it.

This narrows the gap the -Wdocumentation pragma needs to cover; fully
replacing the Doxygen-only commands it also hides (item 2c) is left
for after #5267.

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

#5725 item 2

* Fix -Wextra-semi-stmt at its actual source, not assert()

clang_flags.cmake blamed the global -Wno-extra-semi-stmt on assert(),
but assert() expands to an expression under glibc and libc++ and does
not trigger this warning. unit-assert_macro.cpp overrides JSON_ASSERT
with "{if (!(x)) ++assert_counter; }", a bare block followed by a
semicolon at every JSON_ASSERT(...) call site in the library; that
was the actual source of 151 of the 208 -Wextra-semi-stmt sites found
in a Clang 22 -Weverything sweep of the test suite with the flag
removed. Switched to the standard do/while(false) macro idiom, which
does not expand to a statement-plus-semicolon, and corrected the
comment to name the remaining source instead: vendored Doctest's
CAPTURE(x) shim, which already ends in a semicolon.

Verified with clang++ -Wextra-semi-stmt (plus the file's other CI
ignores) that unit-assert_macro.cpp now compiles without any
-Wextra-semi-stmt diagnostic.

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

#5725 item 8 (step 1 of 2; step 2 covers the CAPTURE() call sites)

* Drop the redundant semicolon from CAPTURE() call sites; remove -Wno-extra-semi-stmt

doctest_compatibility.h defines CAPTURE(x) as DOCTEST_CAPTURE(x); (with
a trailing semicolon baked into the macro), specifically so call sites
do not need to add one themselves; most of the ~267 call sites already
follow that convention. The remaining 64 call sites across 20 files
wrote "CAPTURE(x);" anyway, turning into a statement plus an empty
statement and triggering -Wextra-semi-stmt. Dropped the redundant
semicolon at each of those sites.

With item 6 having already made vendored Doctest a SYSTEM include, and
this the last known source of -Wextra-semi-stmt findings, removed the
flag from clang_flags.cmake entirely.

Verified with clang++ -Wextra-semi-stmt (plus the file's other CI
ignores) that all 20 touched files, plus a file with no CAPTURE() use
(unit-json_pointer.cpp), compile without any -Wextra-semi-stmt
diagnostic.

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

#5725 item 8 (step 2 of 2)

* Switch ci_static_analysis_clang off the frozen LLVM 22 dev image

ubuntu.yml pinned the clang-tidy/clang-tidy-sanitizer/single-binaries
job to silkeh/clang:dev, a tag last pushed 2026-02-18 that reports
"clang version 22.0.0 (...+20251015...)", a pre-release snapshot from
before the LLVM 22 release; the maintainer now updates dev-unstable,
22, and latest instead. Switched to silkeh/clang:22, matching the
other clang jobs on :latest.

Verified with clang-tidy 22.1.8 (the image's actual version) against
this repository's .clang-tidy and library headers what the release
image newly reports compared to :dev:

- readability-redundant-typename fires at ~250 sites across the
  _cpp20-relevant conversion/to_chars headers; the library targets
  C++11 and keeps the typenames, so the check is disabled in
  .clang-tidy, matching how the file already handles checks that
  don't fit a C++11 codebase.
- misc-anonymous-namespace-in-header fires on the two anonymous
  namespaces in from_json.hpp and to_json.hpp; added the alias to
  their existing NOLINT (cert-dcl59-cpp, fuchsia-header-anon-namespaces,
  google-build-namespaces).
- bugprone-std-namespace-modification fires on every addition to
  namespace std: the std::hash, std::formatter and std::swap
  overloads in json.hpp, and the std::tuple_size/std::tuple_element
  specializations in iteration_proxy.hpp (this last file is not named
  in #5725's item 5, found by actually running clang-tidy 22.1.8
  against the current tree). All six are legal, deliberate additions
  to namespace std (explicit/partial specializations of std types, or
  the pre-C++20 std::swap overload); annotated each with the check
  name next to its existing cert-dcl58-cpp NOLINT.
- modernize-avoid-c-style-cast reported nothing new.

Also added clang++-22/21, clang-tidy-22/21, g++-16 and gcov-16 to the
find_program search lists in ci.cmake so a local "maximal warnings"
configure prefers the current toolchain version over an older one on
PATH.

#5725 item 5

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

* Regenerate cmake/gcc_flags.cmake for GCC 16.2.0

GCC_CXXFLAGS was generated for GCC 15.1.0, but ci_test_gcc and
ci_test_gcc_cxx{11..26} now run in gcc:latest, currently GCC 16.2.0,
so the "maximal warnings" job was missing warnings introduced since
15.1.0 while carrying entries GCC 16 treats as duplicates or no-ops.

Regenerated with https://github.com/nlohmann/gcc_flags (patched
locally to not crash on an option whose "-x c++ <opt> -" probe fails
before it reads stdin, e.g. -Wabi=; the tool otherwise raises
BrokenPipeError instead of recording the option as an error) run
against g++ 16.2.0 in the official gcc:16 Docker image, keeping the
documented -Wno-* exclusions and the same alphabetical placement
scheme as before.

Also added three GCC 16 warnings the generator cannot discover on its
own because it only probes value ranges/lists it finds in the -Q
option name itself, not in the enum choices --help=warnings documents
separately:

- -Wbidi-chars=any, -Wleading-whitespace=spaces: manually verified
  these compile cleanly with g++ 16.2.0.
- -Wstrict-flex-arrays: deliberately NOT added, unlike the other two.
  Without -fstrict-flex-arrays (which the library does not enable, as
  it would change codegen for flexible array members), GCC prints
  "'-Wstrict-flex-arrays' is ignored when '-fstrict-flex-arrays' is
  not present" on every translation unit, and under our -Werror that
  note itself aborts the build. This differs from the harmless
  no-op warnings already kept in the file (-Whsa, -Wsynth,
  -Wunreachable-code, -Wunsafe-loop-optimizations), which emit
  nothing; #5725 item 7 named -Wstrict-flex-arrays as one of the
  flags GCC 16 adds, but did not anticipate this failure mode.

Verified: compiled the library header and a representative set of
test translation units (including ones touched by items 1, 3, 8, 9,
10 of this issue) with the regenerated GCC_CXXFLAGS plus -Werror
under g++ 16.2.0 at -std=c++11 through -std=c++26, with zero warnings;
ran the full local test suite (129/129 passing, unrelated to this
compiler) as a regression check. CI must still confirm the actual
ci_test_gcc / ci_test_standards_gcc targets end to end, since this was
verified with direct g++ invocations rather than through the CMake/
CXXFLAGS environment-variable plumbing in ci.cmake.

#5725 item 7

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

* Avoid std::basic_string<CharType> for non-character output_adapter CharType

output_adapter<CharType, StringType> defaulted StringType to
std::basic_string<CharType>, and (with JSON_NO_IO undefined) always
declared a std::basic_ostream<CharType>&-taking constructor. For
CharType with no non-deprecated std::char_traits specialization (only
std::uint8_t is ever used this way, by the binary writers), simply
naming either type - as an unused default template argument, or as an
unused, never-called constructor's parameter type - instantiates
std::char_traits<CharType> merely to name it, which some standard
libraries mark deprecated: with the library-wide -Wdocumentation
pragma (item 2's other half, left for a later commit) temporarily
removed, an Apple clang 21 / libc++ TU calling json::to_cbor(j, vec)
with std::vector<std::uint8_t>& got one -Wdeprecated-declarations
warning per binary writer at the old output_adapters.hpp:193.

Replaced the eager std::basic_string<CharType> / std::basic_ostream
<CharType> defaults with a bool-tagged partial specialization (not
std::conditional, which requires naming both branches' types up
front regardless of which is selected, reproducing the same warning)
that only ever names std::basic_string<CharType> / std::basic_ostream
<CharType> when CharType is actually one of char, wchar_t, char16_t,
char32_t, or (with __cpp_lib_char8_t) char8_t. For any other
CharType, output_adapter's StringType and ostream-constructor
parameter fall back to two distinct empty placeholder types, kept
distinct so the two constructor overloads do not collide into a
single redeclaration.

Public API / behavior: passing a std::basic_string<std::uint8_t>& or
std::basic_ostream<std::uint8_t>& directly to a binary writer's
output_adapter now fails to compile instead of compiling with a
deprecation warning; this was neither documented nor tested. All
documented uses (std::vector<CharType>, std::basic_ostream<CharType>
and StringType for character CharType) are unaffected.

Verified with Apple clang 21 / libc++, with the two -Wdocumentation*
"ignored" pragma lines in macro_scope.hpp temporarily removed and
-std=c++11/c++20 plus the project's -Weverything flag set: calling
to_cbor/to_msgpack/to_ubjson/to_bjdata/to_bson/to_bon8 on a
std::vector<std::uint8_t> now produces no char_traits<unsigned char>
(or any other) deprecation warning, while the char-based string- and
ostream-adapter paths, and a to_cbor/from_cbor round trip, still
compile and run correctly; also verified with GCC 16.2.0. Ran the
full local test suite, including the binary-format unit tests
(unit-cbor, unit-msgpack, unit-ubjson, unit-bjdata, unit-bson,
unit-bon8, unit-binary_writer_sinks, unit-binary_formats,
unit-custom-binary-type): 129/129 passing.

#5725 item 2 (step a)

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

* Remove the library-wide -Wdocumentation pragma; fix what it hid

macro_scope.hpp / macro_unscope.hpp pushed and popped a Clang
diagnostic region over the entire library that ignored -Wdocumentation
and -Wdocumentation-unknown-command. Removed both pragmas and fixed
every finding a full -Wdocumentation (which implies
-Wdocumentation-unknown-command and -Wdocumentation-deprecated-sync)
build reports, so the library now compiles clean under Clang's
documentation checks without a blanket suppression. Overlaps #5267,
which is still open and edits a nearby doc block (json.hpp's
get()/get_impl() @return, already fixed in the item 2 step (b) commit
of this branch); this commit does not touch that block again.

Unknown Doxygen alias commands (Doxyfile removed in #3071, so these
were never rendered by anything) rewritten as plain prose, keeping the
same information:
- @requirement REQ-JSON-01 / REQ-JSON-02 (iter_impl.hpp,
  json_reverse_iterator.hpp): now "This class satisfies the following
  concept requirements (REQ-JSON-0N):".
- @liveexample{prose,example-id} (three sites in json.hpp): kept the
  prose, dropped the command wrapper and the trailing example-id
  (docs/mkdocs/docs/examples/*.cpp still exist and are used directly
  by the rendered docs, not through this in-header alias) and
  unescaped the "\," commas that were only needed for the old alias's
  comma-separated argument syntax.
- @complexity X (json.hpp x4, json_pointer.hpp x2, serializer.hpp x1):
  now "Complexity: X".

Backslash sequences Clang's comment lexer tried to parse as commands,
escaped to render as literal backslashes:
- lexer.hpp get_codepoint(): two `\u` occurrences.
- binary_reader.hpp get_bson_cstr() / get_bson_cstr_bulk(): two
  `\x00` occurrences.
- serializer.hpp: three `\uXXXX` occurrences (constructor @param,
  append_codepoint_to_string_buffer() @brief, and the ensure_ascii
  member comment).

One finding remained after all of the above: Clang reports
"declaration is marked with '@deprecated' command but does not have a
deprecation attribute" on the deprecated sax_parse(span_input_adapter&&, ...)
overload, even though JSON_HEDLEY_DEPRECATED_FOR does expand to
__attribute__((deprecated(...))) for Clang. Several isolated
reproductions of this exact declaration shape - doc comment,
template<>, two stacked __attribute__ macros, an overload set sharing
the name - did not reproduce the warning, so this looks like a
Clang comment/declaration-association quirk specific to this overload
inside the much larger basic_json class template, not an actual
documentation defect. Rather than keep the pragma library-wide for one
Clang false positive, added a tightly scoped
-Wdocumentation-deprecated-sync push/pop around just that overload.

Verified with Apple clang 21 and the project's actual -Weverything
flag set (cmake/clang_flags.cmake) on the full header at -std=c++11
and -std=c++20: zero -Wdocumentation* diagnostics. Also compiled
clean with GCC 16.2.0 (the pragmas are already __clang__-gated, so
this only confirms no unrelated breakage). Ran make check-amalgamation
and the full local test suite: 129/129 passing.

#5725 item 2 (step c)

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

* Take the JSON value by const reference in the array and tuple from_json paths

Review feedback on #5737 (gregmarr): once the no-op std::forward calls
are gone, the forwarding references have no purpose. from_json_fn
passes the value as const BasicJsonType&, so these functions were only
ever instantiated with a const lvalue anyway.

The std::array, std::pair and std::tuple overloads of from_json and
their helpers now take const BasicJsonType& and pass j on unchanged.
Because the deduced BasicJsonType is now the plain type, tuple_type and
the static_assert name const BasicJsonType& explicitly, so the
reference checks are unchanged: get<std::tuple<const std::string&>>()
still works, and get<std::tuple<std::string&>>() still fails the same
static_assert. from_json_tuple_get_impl keeps its forwarding reference,
since tuple_type calls it through std::declval.

Behavior, the public API and the ABI do not change. unit-conversions,
unit-constructor1, unit-udt, unit-udt_macro, unit-regression1/2/3,
unit-deserialization, unit-noexcept, unit-items, unit-allocator,
unit-custom-object-type, unit-ordered_json2 and
unit-brace-init-copy-semantics pass at C++11, C++17 and C++20 with
unchanged assertion counts. Ran make amalgamate.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 07:37:47 +02:00

560 lines
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// __ _____ _____ _____
// __| | __| | | | 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
#pragma once
#include <nlohmann/detail/macro_scope.hpp> // JSON_HAS_CPP_17
#ifdef JSON_HAS_CPP_17
#include <optional> // optional
#endif
#include <algorithm> // copy
#include <iterator> // begin, end
#include <memory> // allocator_traits
#include <string> // basic_string, char_traits
#include <tuple> // tuple, get
#include <type_traits> // is_same, is_constructible, is_floating_point, is_enum, underlying_type
#include <utility> // move, forward, declval, pair
#include <valarray> // valarray
#include <vector> // vector
#include <nlohmann/detail/iterators/iteration_proxy.hpp>
#include <nlohmann/detail/meta/cpp_future.hpp>
#include <nlohmann/detail/meta/std_fs.hpp>
#include <nlohmann/detail/meta/type_traits.hpp>
#include <nlohmann/detail/value_t.hpp>
NLOHMANN_JSON_NAMESPACE_BEGIN
namespace detail
{
//////////////////
// constructors //
//////////////////
/*
* Note all external_constructor<>::construct functions need to call
* j.m_data.m_value.destroy(j.m_data.m_type) to avoid a memory leak in case j contains an
* allocated value (e.g., a string). See bug issue
* https://github.com/nlohmann/json/issues/2865 for more information.
*/
template<value_t> struct external_constructor;
template<>
struct external_constructor<value_t::boolean>
{
template<typename BasicJsonType>
static void construct(BasicJsonType& j, typename BasicJsonType::boolean_t b) noexcept
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::boolean;
j.m_data.m_value = b;
j.assert_invariant();
}
};
template<>
struct external_constructor<value_t::string>
{
template<typename BasicJsonType>
static void construct(BasicJsonType& j, const typename BasicJsonType::string_t& s)
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::string;
j.m_data.m_value = s;
j.assert_invariant();
}
template<typename BasicJsonType>
static void construct(BasicJsonType& j, typename BasicJsonType::string_t&& s)
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::string;
j.m_data.m_value = std::move(s);
j.assert_invariant();
}
template < typename BasicJsonType, typename CompatibleStringType,
enable_if_t < !std::is_same<CompatibleStringType, typename BasicJsonType::string_t>::value,
int > = 0 >
static void construct(BasicJsonType& j, const CompatibleStringType& str)
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::string;
j.m_data.m_value.string = j.template create<typename BasicJsonType::string_t>(str);
j.assert_invariant();
}
};
template<>
struct external_constructor<value_t::binary>
{
template<typename BasicJsonType>
static void construct(BasicJsonType& j, const typename BasicJsonType::binary_t& b)
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::binary;
j.m_data.m_value = typename BasicJsonType::binary_t(b);
j.assert_invariant();
}
template<typename BasicJsonType>
static void construct(BasicJsonType& j, typename BasicJsonType::binary_t&& b)
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::binary;
j.m_data.m_value = typename BasicJsonType::binary_t(std::move(b));
j.assert_invariant();
}
};
template<>
struct external_constructor<value_t::number_float>
{
template<typename BasicJsonType>
static void construct(BasicJsonType& j, typename BasicJsonType::number_float_t val) noexcept
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::number_float;
j.m_data.m_value = val;
j.assert_invariant();
}
};
template<>
struct external_constructor<value_t::number_unsigned>
{
template<typename BasicJsonType>
static void construct(BasicJsonType& j, typename BasicJsonType::number_unsigned_t val) noexcept
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::number_unsigned;
j.m_data.m_value = val;
j.assert_invariant();
}
};
template<>
struct external_constructor<value_t::number_integer>
{
template<typename BasicJsonType>
static void construct(BasicJsonType& j, typename BasicJsonType::number_integer_t val) noexcept
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::number_integer;
j.m_data.m_value = val;
j.assert_invariant();
}
};
template<>
struct external_constructor<value_t::array>
{
template<typename BasicJsonType>
static void construct(BasicJsonType& j, const typename BasicJsonType::array_t& arr)
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::array;
j.m_data.m_value = arr;
j.set_parents();
j.assert_invariant();
}
template<typename BasicJsonType>
static void construct(BasicJsonType& j, typename BasicJsonType::array_t&& arr)
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::array;
j.m_data.m_value = std::move(arr);
j.set_parents();
j.assert_invariant();
}
template < typename BasicJsonType, typename CompatibleArrayType,
enable_if_t < !std::is_same<CompatibleArrayType, typename BasicJsonType::array_t>::value
#if JSON_HAS_RANGES && !defined(__MINGW32__)
&& !is_compatible_range_view<CompatibleArrayType>::value
#endif
, int > = 0 >
static void construct(BasicJsonType& j, const CompatibleArrayType& arr)
{
using std::begin;
using std::end;
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::array;
j.m_data.m_value.array = j.template create<typename BasicJsonType::array_t>(begin(arr), end(arr));
j.set_parents();
j.assert_invariant();
}
template<typename BasicJsonType>
static void construct(BasicJsonType& j, const std::vector<bool>& arr)
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::array;
j.m_data.m_value = value_t::array;
j.m_data.m_value.array->reserve(arr.size());
for (const bool x : arr)
{
j.m_data.m_value.array->push_back(x);
j.set_parent(j.m_data.m_value.array->back());
}
j.assert_invariant();
}
template<typename BasicJsonType, typename T,
enable_if_t<std::is_convertible<T, BasicJsonType>::value, int> = 0>
static void construct(BasicJsonType& j, const std::valarray<T>& arr)
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::array;
j.m_data.m_value = value_t::array;
j.m_data.m_value.array->resize(arr.size());
std::copy(std::begin(arr), std::end(arr), j.m_data.m_value.array->begin());
j.set_parents();
j.assert_invariant();
}
// std::ranges does not work properly on MinGW due to incomplete C++20 support
// see https://github.com/nlohmann/json/issues/4916
#if JSON_HAS_RANGES && !defined(__MINGW32__)
template<typename BasicJsonType, typename CompatibleArrayType,
enable_if_t<is_compatible_range_view<std::remove_cvref_t<CompatibleArrayType>>::value, int> = 0>
static void construct(BasicJsonType& j, CompatibleArrayType && arr)
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::array;
j.m_data.m_value = value_t::array;
for (auto&& x : std::forward<CompatibleArrayType>(arr))
{
j.m_data.m_value.array->push_back(x);
j.set_parent(j.m_data.m_value.array->back());
}
j.assert_invariant();
}
#endif
};
template<>
struct external_constructor<value_t::object>
{
template<typename BasicJsonType>
static void construct(BasicJsonType& j, const typename BasicJsonType::object_t& obj)
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::object;
j.m_data.m_value = obj;
j.set_parents();
j.assert_invariant();
}
template<typename BasicJsonType>
static void construct(BasicJsonType& j, typename BasicJsonType::object_t&& obj)
{
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::object;
j.m_data.m_value = std::move(obj);
j.set_parents();
j.assert_invariant();
}
template < typename BasicJsonType, typename CompatibleObjectType,
enable_if_t < !std::is_same<CompatibleObjectType, typename BasicJsonType::object_t>::value, int > = 0 >
static void construct(BasicJsonType& j, const CompatibleObjectType& obj)
{
using std::begin;
using std::end;
j.m_data.m_value.destroy(j.m_data.m_type);
j.m_data.m_type = value_t::object;
j.m_data.m_value.object = j.template create<typename BasicJsonType::object_t>(begin(obj), end(obj));
j.set_parents();
j.assert_invariant();
}
};
/////////////
// to_json //
/////////////
#ifdef JSON_HAS_CPP_17
template<typename BasicJsonType, typename T,
enable_if_t<std::is_constructible<BasicJsonType, T>::value, int> = 0>
void to_json(BasicJsonType& j, const std::optional<T>& opt) noexcept(std::is_nothrow_assignable<BasicJsonType&, const T&>::value)
{
if (opt.has_value())
{
j = *opt;
}
else
{
j = nullptr;
}
}
#endif
template<typename BasicJsonType, typename T,
enable_if_t<std::is_same<T, typename BasicJsonType::boolean_t>::value, int> = 0>
inline void to_json(BasicJsonType& j, T b) noexcept
{
external_constructor<value_t::boolean>::construct(j, b);
}
template < typename BasicJsonType, typename BoolRef,
enable_if_t <
((std::is_same<std::vector<bool>::reference, BoolRef>::value
&& !std::is_same <std::vector<bool>::reference, typename BasicJsonType::boolean_t&>::value)
|| (std::is_same<std::vector<bool>::const_reference, BoolRef>::value
&& !std::is_same <detail::uncvref_t<std::vector<bool>::const_reference>,
typename BasicJsonType::boolean_t >::value))
&& std::is_convertible<const BoolRef&, typename BasicJsonType::boolean_t>::value, int > = 0 >
inline void to_json(BasicJsonType& j, const BoolRef& b) noexcept
{
external_constructor<value_t::boolean>::construct(j, static_cast<typename BasicJsonType::boolean_t>(b));
}
template<typename BasicJsonType, typename CompatibleString,
enable_if_t<std::is_constructible<typename BasicJsonType::string_t, CompatibleString>::value, int> = 0>
inline void to_json(BasicJsonType& j, const CompatibleString& s)
{
external_constructor<value_t::string>::construct(j, s);
}
template<typename BasicJsonType>
inline void to_json(BasicJsonType& j, typename BasicJsonType::string_t&& s)
{
external_constructor<value_t::string>::construct(j, std::move(s));
}
template<typename BasicJsonType, typename FloatType,
enable_if_t<std::is_floating_point<FloatType>::value, int> = 0>
inline void to_json(BasicJsonType& j, FloatType val) noexcept
{
external_constructor<value_t::number_float>::construct(j, static_cast<typename BasicJsonType::number_float_t>(val));
}
template<typename BasicJsonType, typename CompatibleNumberUnsignedType,
enable_if_t<is_compatible_integer_type<typename BasicJsonType::number_unsigned_t, CompatibleNumberUnsignedType>::value, int> = 0>
inline void to_json(BasicJsonType& j, CompatibleNumberUnsignedType val) noexcept
{
external_constructor<value_t::number_unsigned>::construct(j, static_cast<typename BasicJsonType::number_unsigned_t>(val));
}
template<typename BasicJsonType, typename CompatibleNumberIntegerType,
enable_if_t<is_compatible_integer_type<typename BasicJsonType::number_integer_t, CompatibleNumberIntegerType>::value, int> = 0>
inline void to_json(BasicJsonType& j, CompatibleNumberIntegerType val) noexcept
{
external_constructor<value_t::number_integer>::construct(j, static_cast<typename BasicJsonType::number_integer_t>(val));
}
#if !JSON_DISABLE_ENUM_SERIALIZATION
template<typename BasicJsonType, typename EnumType,
enable_if_t<std::is_enum<EnumType>::value, int> = 0>
inline void to_json(BasicJsonType& j, EnumType e) noexcept
{
using underlying_type = typename std::underlying_type<EnumType>::type;
static constexpr value_t integral_value_t = std::is_unsigned<underlying_type>::value ? value_t::number_unsigned : value_t::number_integer;
external_constructor<integral_value_t>::construct(j, static_cast<underlying_type>(e));
}
#endif // JSON_DISABLE_ENUM_SERIALIZATION
template<typename BasicJsonType>
inline void to_json(BasicJsonType& j, const std::vector<bool>& e)
{
external_constructor<value_t::array>::construct(j, e);
}
template < typename BasicJsonType, typename CompatibleArrayType,
enable_if_t < is_compatible_array_type<BasicJsonType,
CompatibleArrayType>::value&&
!is_compatible_object_type<BasicJsonType, CompatibleArrayType>::value&&
!is_compatible_string_type<BasicJsonType, CompatibleArrayType>::value&&
!std::is_same<typename BasicJsonType::binary_t, CompatibleArrayType>::value&&
!is_compatible_binary_type<BasicJsonType, CompatibleArrayType>::value&&
!is_basic_json<CompatibleArrayType>::value
#if JSON_HAS_RANGES && !defined(__MINGW32__)
&& !is_compatible_range_view<CompatibleArrayType>::value
#endif
,
int > = 0 >
inline void to_json(BasicJsonType& j, const CompatibleArrayType& arr)
{
external_constructor<value_t::array>::construct(j, arr);
}
#if JSON_HAS_RANGES && !defined(__MINGW32__)
template < typename BasicJsonType, typename T,
enable_if_t < is_compatible_range_view<std::remove_cvref_t<T>>::value
&& !is_compatible_string_type<BasicJsonType, std::remove_cvref_t<T>>::value
&& !is_compatible_object_type<BasicJsonType, std::remove_cvref_t<T>>::value
&& !is_basic_json<std::remove_cvref_t<T>>::value, int > = 0 >
inline void to_json(BasicJsonType& j, T && arr)
{
external_constructor<value_t::array>::construct(j, std::forward<T>(arr));
}
#endif
template<typename BasicJsonType>
inline void to_json(BasicJsonType& j, const typename BasicJsonType::binary_t& bin)
{
external_constructor<value_t::binary>::construct(j, bin);
}
template < typename BasicJsonType, typename CompatibleArrayType,
enable_if_t < is_compatible_binary_type<BasicJsonType, CompatibleArrayType>::value,
int > = 0 >
inline void to_json(BasicJsonType& j, const CompatibleArrayType& bin)
{
external_constructor<value_t::binary>::construct(j, typename BasicJsonType::binary_t(bin));
}
template<typename BasicJsonType, typename T,
enable_if_t<std::is_convertible<T, BasicJsonType>::value, int> = 0>
inline void to_json(BasicJsonType& j, const std::valarray<T>& arr)
{
external_constructor<value_t::array>::construct(j, std::move(arr));
}
template<typename BasicJsonType>
inline void to_json(BasicJsonType& j, typename BasicJsonType::array_t&& arr)
{
external_constructor<value_t::array>::construct(j, std::move(arr));
}
template < typename BasicJsonType, typename CompatibleObjectType,
enable_if_t < is_compatible_object_type<BasicJsonType, CompatibleObjectType>::value&& !is_basic_json<CompatibleObjectType>::value, int > = 0 >
inline void to_json(BasicJsonType& j, const CompatibleObjectType& obj)
{
external_constructor<value_t::object>::construct(j, obj);
}
template<typename BasicJsonType>
inline void to_json(BasicJsonType& j, typename BasicJsonType::object_t&& obj)
{
external_constructor<value_t::object>::construct(j, std::move(obj));
}
template <
typename BasicJsonType, typename T, std::size_t N,
enable_if_t < !std::is_constructible<typename BasicJsonType::string_t,
const T(&)[N]>::value, // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
int > = 0 >
inline void to_json(BasicJsonType& j, const T(&arr)[N]) // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
{
external_constructor<value_t::array>::construct(j, arr);
}
template < typename BasicJsonType, typename T1, typename T2, enable_if_t < std::is_constructible<BasicJsonType, T1>::value&& std::is_constructible<BasicJsonType, T2>::value, int > = 0 >
inline void to_json(BasicJsonType& j, const std::pair<T1, T2>& p)
{
j = { p.first, p.second };
}
// for https://github.com/nlohmann/json/pull/1134
template<typename BasicJsonType, typename T,
enable_if_t<std::is_same<T, iteration_proxy_value<typename BasicJsonType::iterator>>::value, int> = 0>
inline void to_json(BasicJsonType& j, const T& b)
{
j = { {b.key(), b.value()} };
}
template<typename BasicJsonType, typename Tuple, std::size_t... Idx>
inline void to_json_tuple_impl(BasicJsonType& j, const Tuple& t, index_sequence<Idx...> /*unused*/)
{
j = { std::get<Idx>(t)... };
}
// A one-element braced list does not reliably wrap its element: with
// JSON_BRACE_INIT_COPY_SEMANTICS it copies it, which would serialize
// std::tuple<int>{5} as 5 rather than [5], and some compilers (e.g., Apple clang
// 15 and 16) copy an element that is itself a basic_json even without it, so
// std::tuple<json>{true} became true rather than [true]. Build what the default
// deduction builds instead: an object if the element is a [string, value] pair,
// a one-element array otherwise.
template<typename BasicJsonType, typename Tuple>
inline void to_json_tuple_impl(BasicJsonType& j, const Tuple& t, index_sequence<0> /*unused*/)
{
BasicJsonType element(std::get<0>(t));
// same test as the initializer-list constructor, including the cast that
// keeps a string type constructible from 0 from selecting operator[](key)
const bool is_member = element.is_array() && element.size() == 2
&& element[static_cast<typename BasicJsonType::size_type>(0)].is_string();
if (is_member)
{
j = BasicJsonType::object({std::move(element)});
}
else
{
j = BasicJsonType::array({std::move(element)});
}
}
template<typename BasicJsonType, typename Tuple>
inline void to_json_tuple_impl(BasicJsonType& j, const Tuple& /*unused*/, index_sequence<> /*unused*/)
{
using array_t = typename BasicJsonType::array_t;
j = array_t();
}
template<typename BasicJsonType, typename T, enable_if_t<is_constructible_tuple<BasicJsonType, T>::value, int > = 0>
inline void to_json(BasicJsonType& j, const T& t)
{
to_json_tuple_impl(j, t, make_index_sequence<std::tuple_size<T>::value> {});
}
#if JSON_HAS_FILESYSTEM || JSON_HAS_EXPERIMENTAL_FILESYSTEM
#if defined(__cpp_lib_char8_t)
template<typename BasicJsonType, typename Tr, typename Allocator>
inline void to_json(BasicJsonType& j, const std::basic_string<char8_t, Tr, Allocator>& s)
{
using OtherAllocator = typename std::allocator_traits<Allocator>::template rebind_alloc<char>;
j = std::basic_string<char, std::char_traits<char>, OtherAllocator>(s.begin(), s.end(), s.get_allocator());
}
#endif
// Workaround for MSVC 19.51 (and possibly later): in large cpp files, the compiler may fail to resolve with generic has_to_json (issue #4996)
template<typename BasicJsonType>
struct has_to_json<BasicJsonType, std_fs::path, void> : std::true_type {};
template<typename BasicJsonType>
inline void to_json(BasicJsonType& j, const std_fs::path& p)
{
// Returns either a std::string or a std::u8string depending whether library
// support for char8_t is enabled.
j = p.u8string();
}
#endif
struct to_json_fn
{
template<typename BasicJsonType, typename T>
auto operator()(BasicJsonType& j, T&& val) const noexcept(noexcept(to_json(j, std::forward<T>(val))))
-> decltype(to_json(j, std::forward<T>(val)), void())
{
return to_json(j, std::forward<T>(val));
}
};
} // namespace detail
#ifndef JSON_HAS_CPP_17
/// namespace to hold default `to_json` function
/// to see why this is required:
/// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4381.html
namespace // NOLINT(cert-dcl59-cpp,fuchsia-header-anon-namespaces,google-build-namespaces,misc-anonymous-namespace-in-header)
{
#endif
JSON_INLINE_VARIABLE constexpr const auto& to_json = // NOLINT(misc-definitions-in-headers)
detail::static_const<detail::to_json_fn>::value;
#ifndef JSON_HAS_CPP_17
} // namespace
#endif
NLOHMANN_JSON_NAMESPACE_END
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