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Author SHA1 Message Date
Niels Lohmann f6b6aaf69f Merge branch 'json-view/16-view-simd' into json-view/18-view-object-index 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:43:56 +02:00
Niels Lohmann d62e3ec9c6 Merge branch 'json-view/15-view-bench' into json-view/16-view-simd 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:43:51 +02:00
Niels Lohmann 3cea705804 Merge branch 'json-view/14b-view-float-layout' into json-view/15-view-bench 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:43:47 +02:00
Niels Lohmann 910fbb4b5c Merge branch 'json-view/14-view-compare' into json-view/14b-view-float-layout 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:43:42 +02:00
Niels Lohmann c8ec867991 Merge branch 'json-view/13-view-dump' into json-view/14-view-compare 
Conflicts in See also lists (docs/mkdocs/docs/api/basic_json/operator_ne.md), where develop (#5638) and this branch both edited: kept develop's entries and added this branch's basic_json_view links.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:43:37 +02:00
Niels Lohmann 2e06ccf0c7 Merge branch 'json-view/12-view-values' into json-view/13-view-dump 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:43:33 +02:00
Niels Lohmann f17207377b Mark an Infer false positive in get_impl() 
The tests added here instantiate basic_json::get() with a type for which Infer 1.3.0 reports STACK_VARIABLE_ADDRESS_ESCAPE on "return ret;", although ret is returned by value. Suppress it on that line, as develop does for its own Infer false positives (#5750).

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:43:28 +02:00
Niels Lohmann 3b30446d1b Merge branch 'json-view/11-view-access' into json-view/12-view-values 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:37:21 +02:00
Niels Lohmann 960d3435a1 Merge branch 'json-view/10-view-document' into json-view/11-view-access 
Conflicts in See also lists (docs/mkdocs/docs/api/basic_json/begin.md,docs/mkdocs/docs/api/basic_json/cbegin.md,docs/mkdocs/docs/api/basic_json/cend.md,docs/mkdocs/docs/api/basic_json/end.md,docs/mkdocs/docs/api/basic_json/type_name.md), where develop (#5638) and this branch both edited: kept develop's entries and added this branch's basic_json_view links.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:37:16 +02:00
Niels Lohmann ceb1cdb774 Merge branch 'json-view/08-view-builder' into json-view/10-view-document 
Conflicts in the See also lists of nine basic_json pages, is_discarded.md, and features/index.md, where develop (#5638) and this branch both added entries: kept both. Ran make amalgamate.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:36:41 +02:00
Niels Lohmann 80761cf255 Merge branch 'json-view/04-unicode-escapes' into json-view/08-view-builder 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:36:09 +02:00
Niels Lohmann eed512f1d5 Merge branch 'json-view/03-string-scan' into json-view/04-unicode-escapes 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:36:05 +02:00
Niels Lohmann 3f672f036d Merge branch 'json-view/02b-float-parser' into json-view/03-string-scan 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:36:00 +02:00
Niels Lohmann 83302ff69d Merge branch 'develop' into json-view/02b-float-parser 
Conflicts:
- number_parse.hpp: kept this branch's float parser, which replaces the
  Eisel-Lemire code that develop's side changed (#5750 made its digit
  counter unsigned; this parser has no such counter, and it compiles
  cleanly with GCC's -Wstrict-overflow=5).
- number_handling.md, template_parameters.md: kept this branch's
  description of the conversion and added develop's "Before version
  3.13.0" sentence.

Ran make amalgamate.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:35:40 +02:00
Niels Lohmann 63c10a51fc Review and extend the documentation, and check it in CI (#5638) 
* Review and extend the documentation, and check it in CI

A review of all documentation pages found factual errors, dead links,
missing cross-references, and gaps in examples. This fixes them and adds
checks so the same problems are caught automatically.

Fixes:
- wrong signatures and version histories (operator!= C++20 member,
  binary() subtype type, get<PointerType>(), JSON_NO_THREAD_LOCAL, ...)
- stale descriptions (number parsing since #5283, UBJSON table, SAX
  example that no longer compiled, tsl::ordered_map advice)
- dead internal and external links; repology.org badges (the domain is
  suspended) replaced by badges that query the registries directly
- deprecation notes link the migration guide; the guide itself fixed

Additions:
- "See also" sections, cross-references, 25 runnable examples, 12
  Mermaid diagrams, new API pages for json_pointer::operator<=> and
  byte_container_with_subtype::operator==/!=
- landing page, guides for untrusted input and performance
- "unreleased" badge after versions newer than the latest release

Checks:
- strict documentation build (broken links/anchors fail it); CI and
  the publish workflow fetch the full history the build needs
- weekly external link check, Mermaid syntax check in CI
- check_structure.py: example titles, heading levels, alt texts,
  header links, docset index coverage; its unused-example check works
  again
- all examples produce the same output on every platform

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

* Keep the customer links that could not be fixed

A dead link on the customers page is still the evidence of where the
use of the library was documented. Keep the original URLs of the entries
without a working replacement (Marne, Cisco Webex Desk Camera, Philips
Hue, CyberArk) and exclude exactly these URLs from the link check.

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

* Correct the duplicate-key recipe's claim about SAX positions

The SAX interface's key() receives no position either; only parse_error()
does. Also note that the recipe does not report the path to the repeated
key (see discussion #5085).

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

* Say the library is available as a single header and mention json_fwd.hpp

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

* Correct documentation errors found while hunting for bugs

- patch/patch_inplace: list the JSON pointer errors parse_error.106-109
  and out_of_range.402/404, and quote the actual parse_error.105 message.
- unflatten: list parse_error.106/107/108 and out_of_range.404.
- to_bson: list out_of_range.415 (binary subtype above 255) and note
  that 412 and 415 are new in 3.13.0.
- to_string: state that string_t must be convertible to std::string, also
  in the StringType requirements table.
- JSON Lines: a `while (input >> j)` loop also throws after the last value
  for concatenated JSON values; show a loop that works for both.
- BON8: a string gets 0xFF only if nothing follows it in the message; a
  string at the end of an array or object is ended by 0xFE.
- custom_string_type.hpp: add operator+=(char), which the "Always
  required" list asks for (json_pointer::to_string, flatten, unflatten,
  and diff did not compile), and an ADL int_to_string for diff and items.

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

* Cache the release headers with functools.lru_cache

Codacy (Pylint) flagged the mutable default argument that header() used
as its cache. functools.lru_cache keeps the same memoization without it.
The script's output is unchanged.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:32:15 +02:00
dependabot[bot] 48ff79647f Bump the codeql-action group with 4 updates (#5743) 
Bumps the codeql-action group with 4 updates: [github/codeql-action/init](https://github.com/github/codeql-action), [github/codeql-action/autobuild](https://github.com/github/codeql-action), [github/codeql-action/analyze](https://github.com/github/codeql-action) and [github/codeql-action/upload-sarif](https://github.com/github/codeql-action).


Updates `github/codeql-action/init` from 4.38.1 to 4.38.2
- [Release notes](https://github.com/github/codeql-action/releases)
- [Changelog](https://github.com/github/codeql-action/blob/main/CHANGELOG.md)
- [Commits](https://github.com/github/codeql-action/compare/1c5b675653bb5c22dbe9b12b556ec555138e09fd...2892aa5e19bbd11bc0cff5427e3b750a04d9e3c2)

Updates `github/codeql-action/autobuild` from 4.38.1 to 4.38.2
- [Release notes](https://github.com/github/codeql-action/releases)
- [Changelog](https://github.com/github/codeql-action/blob/main/CHANGELOG.md)
- [Commits](https://github.com/github/codeql-action/compare/1c5b675653bb5c22dbe9b12b556ec555138e09fd...2892aa5e19bbd11bc0cff5427e3b750a04d9e3c2)

Updates `github/codeql-action/analyze` from 4.38.1 to 4.38.2
- [Release notes](https://github.com/github/codeql-action/releases)
- [Changelog](https://github.com/github/codeql-action/blob/main/CHANGELOG.md)
- [Commits](https://github.com/github/codeql-action/compare/1c5b675653bb5c22dbe9b12b556ec555138e09fd...2892aa5e19bbd11bc0cff5427e3b750a04d9e3c2)

Updates `github/codeql-action/upload-sarif` from 4.38.1 to 4.38.2
- [Release notes](https://github.com/github/codeql-action/releases)
- [Changelog](https://github.com/github/codeql-action/blob/main/CHANGELOG.md)
- [Commits](https://github.com/github/codeql-action/compare/1c5b675653bb5c22dbe9b12b556ec555138e09fd...2892aa5e19bbd11bc0cff5427e3b750a04d9e3c2)

---
updated-dependencies:
- dependency-name: github/codeql-action/init
  dependency-version: 4.38.2
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: codeql-action
- dependency-name: github/codeql-action/autobuild
  dependency-version: 4.38.2
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: codeql-action
- dependency-name: github/codeql-action/analyze
  dependency-version: 4.38.2
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: codeql-action
- dependency-name: github/codeql-action/upload-sarif
  dependency-version: 4.38.2
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: codeql-action
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
 2026-10-02 11:24:33 +02:00
Niels Lohmann 4d46bce4e1 Fix CI on develop (#5750) 
* Fix CI configuration broken by recent merges and tool updates

- gcc_flags.cmake: drop -Wexperimental-fmv-target, which GCC 16 accepts
  only on aarch64; amd64 rejects it, so every GCC job failed while
  checking the compiler.
- ci_get_cmake: add VERBATIM so the checksum pipeline is passed to the
  shell intact (the unescaped `$'` broke the generated Makefile and
  build.ninja, failing ci_cmake_flags and ci_module_cpp20); match the
  SHA-256 entry case-insensitively, as CMake 3.5.0 lists the archive as
  "Linux-x86_64"; and unpack with --strip-components, as that archive's
  top-level directory is spelled "Linux" too.
- ci_single_binaries: compile json.hpp's TU without IWYU's --error, as
  the comment above the gate already intends.
- tests: restore -Wno-deprecated-declarations for all non-MSVC compilers
  (#5737 kept it for GCC only), as several tests call deprecated
  functions on purpose; include thirdparty/fifo_map as SYSTEM.
- .clang-tidy: set misc-use-internal-linkage.AnalyzeTypes to false;
  clang-tidy 22.1 extended the check to classes and enums and flagged
  100 test helper types.

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

* Fix library warnings and a JSON_DIAGNOSTICS parent bug

- binary_reader: pass integers to sax->number_integer() through
  conditional_static_cast<number_integer_t>, making the existing
  narrowing for a narrow number_integer_t explicit (MSVC C4244 and GCC
  -Wconversion/-Warith-conversion with the int16_t test from #5694);
  mark two Infer DEAD_STORE false positives with @infer-ignore.
- to_json: set the parents of an array built from a C++20 range view
  after all elements are in place; a reallocating push_back moved the
  earlier elements and left their parent pointers stale, failing the
  JSON_DIAGNOSTICS invariant assertion.
- json.hpp: suppress MSVC C4127 for the new is_ordered_map check in
  diff(), like the three existing ones; spell out std::formatter::parse's
  return and iterator types for clang-tidy 22.1.
- number_parse: make the Eisel-Lemire digit counter unsigned
  (GCC -Wstrict-overflow).
- string_utils: take encode_utf8's callable by const reference
  (cppcoreguidelines-missing-std-forward) and drop a \u from its doc
  comment (-Wdocumentation-unknown-command).
- ordered_map: include <memory> for std::allocator (cpplint).

Ran make amalgamate.

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

* Fix tests failing in CI on develop

- unit-allocator: skip the #5640 test under MSVC STL iterator debugging,
  where containers allocate a debug proxy in noexcept move constructors
  and a failing allocation terminates; move a decrement out of an if
  condition (bugprone-inc-dec-in-conditions).
- unit-conversions: expect the "(/0)" path with JSON_DIAGNOSTICS;
  compare strict enums via get<>() rather than through the noexcept
  operator==(ScalarType, json), which bugprone-exception-escape flags.
- unit-alt-string: suppress -Wexit-time-destructors for the strict enum
  macro and misc-use-internal-linkage for its enum.
- unit-bjdata: call the static lookup functions through the type and
  pass unsigned char (-Wsign-conversion on amd64).
- Mark Infer false positives with @infer-ignore in unit-diagnostics,
  unit-pointer_access, unit-udt, and unit-conversions.
- Smaller clang-tidy 22.1 findings in unit-class_parser,
  unit-constructor2, unit-custom-base-class, unit-locale-cpp, and
  unit-noexcept.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 11:23:55 +02:00
Niels Lohmann 6aec1a085f Report BON8 input that ends after a UTF-8 lead byte as truncated (#5677) 
A lead byte (0xC2..0xF7) inside a string begins either another character
(if a continuation byte follows) or an integer (otherwise). When the input
ended right after the lead byte, the reader took the missing byte as "not
a continuation byte", ended the string before the lead byte, and treated
the lead byte as the start of the next value. With strict=false, a message
cut off there was therefore read as a shorter value: the 11 bytes of
"😀😀é" cut after 9 bytes gave "😀😀", and ["aé"] cut after 3 of its 5
bytes gave ["a"]. With strict=true, the input was rejected with a
misleading message ("expected end of input"), or, for a key, with
parse_error.112 instead of 110.

Either reading of the lead byte leaves the message incomplete: a string at
the end of a message must be terminated by 0xFF, so the lead byte cannot
belong to a following message. Report parse_error.110 (unexpected end of
input) for strings and keys, as the comment on get_bon8_string() already
requires and as the reference decoder (HikoGUI) does.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-02 07:47:50 +02:00
Niels Lohmann 11e75a5428 Cancel CI runs of merged and closed pull requests (#5748) 2026-10-01 10:53:10 +02:00
Niels Lohmann 95c8d2aa46 Merge branch 'json-view/16-view-simd' into json-view/18-view-object-index 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:28:52 +02:00
Niels Lohmann d38f5f111f Merge branch 'json-view/15-view-bench' into json-view/16-view-simd 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:28:48 +02:00
Niels Lohmann 057c86de8c Mark compare.py's subprocess and download calls for Bandit 
The commands are argument lists the script builds itself, and the
downloads are pinned https URLs whose SHA-256 is checked.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:28:47 +02:00
Niels Lohmann 448a90909e Merge branch 'json-view/14b-view-float-layout' into json-view/15-view-bench 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:27:46 +02:00
Niels Lohmann d9e4155ba1 Merge branch 'json-view/14-view-compare' into json-view/14b-view-float-layout 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:27:39 +02:00
Niels Lohmann 7130880754 Merge branch 'json-view/13-view-dump' into json-view/14-view-compare 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:27:30 +02:00
Niels Lohmann 89bf08760f Merge branch 'json-view/12-view-values' into json-view/13-view-dump 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:27:23 +02:00
Niels Lohmann b1595c1b40 Merge branch 'json-view/11-view-access' into json-view/12-view-values 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:27:13 +02:00
Niels Lohmann 3d6d610fdc Merge branch 'json-view/10-view-document' into json-view/11-view-access 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:27:03 +02:00
Niels Lohmann 134b2f0efe Mark json_view.hpp's read() and strlen as Flawfinder false positives 
json_document::read is a member function, not POSIX read(), and the C
string overload requires null-terminated input like json::parse.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:27:01 +02:00
Niels Lohmann dddb2d6e43 Merge branch 'json-view/08-view-builder' into json-view/10-view-document 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:26:20 +02:00
Niels Lohmann b59fc6c902 Mark string_ref's strlen as a Flawfinder false positive 
string_ref(const char*) requires a null-terminated string, like
std::string_view's constructor.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:26:18 +02:00
Niels Lohmann c6ac5c85c2 Merge branch 'json-view/16-view-simd' into json-view/18-view-object-index 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:20:06 +02:00
Niels Lohmann 0e57b3fb28 Merge branch 'json-view/15-view-bench' into json-view/16-view-simd 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:20:04 +02:00
Niels Lohmann d575be3e55 Merge branch 'json-view/14b-view-float-layout' into json-view/15-view-bench 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:20:02 +02:00
Niels Lohmann 94c518f94d Merge branch 'json-view/14-view-compare' into json-view/14b-view-float-layout 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:19:59 +02:00
Niels Lohmann 76ce7e2c84 Merge branch 'json-view/13-view-dump' into json-view/14-view-compare 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:19:57 +02:00
Niels Lohmann 5277335a9e Merge branch 'json-view/12-view-values' into json-view/13-view-dump 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:19:55 +02:00
Niels Lohmann 05b6cd0892 Merge branch 'json-view/11-view-access' into json-view/12-view-values 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:19:53 +02:00
Niels Lohmann 95d10dab70 Merge branch 'json-view/10-view-document' into json-view/11-view-access 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:19:51 +02:00
Niels Lohmann 371a8a3d9f Merge branch 'json-view/08-view-builder' into json-view/10-view-document 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

# Conflicts:
#	Makefile
#	cmake/ci.cmake
 2026-10-01 10:19:49 +02:00
Niels Lohmann ae01d57694 Merge branch 'json-view/03-string-scan' into json-view/04-unicode-escapes 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:18:33 +02:00
Niels Lohmann 6a757ca675 Merge branch 'json-view/02b-float-parser' into json-view/03-string-scan 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:18:33 +02:00
Niels Lohmann cb51f80e34 Merge branch 'json-view/04-unicode-escapes' into json-view/08-view-builder 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 10:18:33 +02:00
Niels Lohmann 9d44e3f359 Merge branch 'develop' into json-view/02b-float-parser 
Conflicted only in tests/src/unit-class_lexer.cpp, where develop's #5737
lint fix (CAPTURE(x); -> CAPTURE(x)) collided with this PR's rewrite of
the Eisel-Lemire float tests; kept the PR's new tests and applied the
lint-fixed CAPTURE style. single_include regenerated via make amalgamate.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 08:53:02 +02:00
Niels Lohmann e400780533 Re-amalgamate single_include (#5745) 
* Re-amalgamate single_include

#5737 changed 13 headers under include/ but merged without the matching
single_include/nlohmann/json.hpp update, so the amalgamated header still
had, among others, the GCC C++20 -Wignored-attributes pragma block and
the clang -Wdocumentation push/pop that #5737 removed, the forwarding
from_json tuple/array helpers it replaced with const references, and
lacked the output_adapter char_traits changes it added.

Regenerated with `make amalgamate` (astyle 3.4.13). The diff is exactly
`git diff b54ed188e e5a89d671 -- include/` (164+/95-); json_fwd.hpp and
json_literals.hpp were already up to date.

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

* Run the amalgamation check on pushes to develop

#5737 was merged 39 seconds after its last push, while its own
check_amalgamation run was still queued (earlier runs had been
cancelled by the concurrency group), so the stale single_include
reached develop without any failing check.

Also run the check on pushes to develop, without cancelling in-progress
develop runs. The "save" job (PR number/author for the comment
workflow) only runs for pull requests, the checkout falls back to
github.sha, and comment_check_amalgamation.yml only comments for
PR-triggered runs, since push runs have no PR and no "pr" artifact.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 08:09:34 +02:00
Niels Lohmann 9d88ead578 Clarify that the strtold fallback substitutes the locale's decimal point 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 07:40:37 +02:00
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
Niels Lohmann b54ed188e6 Remove test debt: dead guards, discarded results, and unreferenced files (#5732) 
* Run the README test case in JSON_FastTests jobs

The "README" test case was marked doctest::skip() when the tests
moved from Catch to doctest in 2019, where it replaced Catch's hidden
tag. It is not slow (17 assertions, about 0.00 s), but cmake/test.cmake
only passes --no-skip when JSON_FastTests is off, so the per-compiler
ci_test_*_cxxNN matrix, macOS, Windows Release/ARM, icpc, icpx and
nvhpc compiled the README examples without running them.

Drop the skip decorator so every job runs the case. Test-only change.

Part of #5713

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

* Remove stale clang ranges guards in unit-iterators2.cpp

The "algorithms" and "views" sections were guarded by clang/libstdc++
checks written for a clang 15 (04/2022) bug. The first guard's
condition contradicts its own comment: it skips clang+libc++ and
keeps clang+libstdc++. Both sections already sit inside
`#if JSON_HAS_RANGES`, which macro_scope.hpp excludes for the
toolchains these guards targeted, so the inner guards never let the
sections run on the platforms they meant to protect and are
redundant on the rest. Verified locally with Apple clang 21/libc++
and clang 16.0.6/libstdc++ 12 (Docker): both pass all 1355
assertions with the guards removed.

Part of #5713

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

* Fix copy-pasted CBOR half-float checks; enable stale encode checks

In the RFC 8949 Appendix A test case, the decode checks for
5.960464477539063e-8 (0xf9 0x00 0x01) and 0.00006103515625
(0xf9 0x04 0x00) were copy-pasted from the neighboring -4.0 example,
so those two half-float byte sequences were never actually decoded
and checked, and -4.0 was checked three times instead. The two
float32 encode checks for 100000.0 and 3.4028234663852886e+38 were
commented out before the writer supported emitting float32 and are
now verified to match byte for byte, so they are enabled. The
remaining commented-out half-precision to_cbor checks are collapsed
into a single explanatory comment, since the writer never emits
half-precision floats.

Part of #5713

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

* Assert on the result of STL container conversions in tests

The "object-like STL containers" and "array-like STL containers"
sections converted json values into std::map, unordered_map,
multimap, unordered_multimap, list, forward_list, array, valarray,
vector, deque, set and unordered_set and discarded the result, so
these ~60 conversions only proved that the code compiles and does
not throw; a conversion that dropped or reordered elements would
still pass. Bind each result and compare it against the expected
container. Also fix a copy-paste slip in the deque section
(`j2.get<std::deque<double>>()` instead of j3, so j3's doubles were
never converted to a deque), and remove the dead
`// CHECK(m5["one"] == "eins")` comments that referred to a variable
that did not exist by asserting the equivalent through the bound
result.

Part of #5713

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

* Deduplicate SaxCountdown and other test helpers across formats

SaxCountdown was copied byte-for-byte into six binary-format test
files (unit-cbor.cpp, unit-msgpack.cpp, unit-ubjson.cpp,
unit-bjdata.cpp, unit-bon8.cpp, unit-bson.cpp), about 370 redundant
lines. Move it into tests/src/sax_countdown.hpp (namespace utils,
alongside test_utils.hpp and round_trip_corpus.hpp) and include it
from all six.

trait_test_arg and the "value_in_range_of trait"
TEST_CASE_TEMPLATE_DEFINE were duplicated between unit-32bit.cpp and
unit-bjdata.cpp; the trait is a detail/meta trait, not specific to
either file. Move it into tests/src/value_in_range_of_test.hpp;
unit-32bit.cpp keeps its own include, since JSON_32bitTest=ONLY
builds only that file. Each file keeps its own
TEST_CASE_TEMPLATE_INVOKE list.

sax_no_exception and the "issue #2824" section were duplicated in
unit-regression2.cpp and unit-disabled_exceptions.cpp. Drop the copy
from unit-regression2.cpp; unit-disabled_exceptions.cpp already
covers the no-exceptions case that #2824 was about, and
ci_test_noexceptions reruns it.

No behavior change. Verified by building and running unit-cbor,
unit-msgpack, unit-ubjson, unit-bjdata, unit-bon8, unit-bson,
unit-32bit, unit-regression2 and unit-disabled_exceptions against
include/ (clang++ -std=c++11, ASan/UBSan where applicable); assertion
counts are unchanged from before the refactor.

Part of #5714

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

* Remove the unreferenced vendored libFuzzer

tests/thirdparty/Fuzzer (155 files, ~776 KB of vendored Apache-2.0
LLVM code from the 2016 OSS-Fuzz import) is not referenced by any
CMakeLists, Makefile or workflow: the fuzz drivers link against
-fsanitize=fuzzer or the repo's own
tests/src/fuzzer-driver_afl.cpp. Its vendored README only points at
llvm.org's own libFuzzer docs. Being dead code, it also adds noise
to the flawfinder code-scanning workflow, which scans the whole
tree. Remove the directory and its .reuse/dep5 entry.

Part of #5714

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

* Remove unreferenced 2016 benchmark and fuzz reports

tests/reports (1.6 MB) holds AFL status pages and plots from
2016-08-29 and 2016-10-02, and a nativejson-benchmark snapshot from
2016 with links to rawgit.com, which shut down in 2019. Nothing
references this directory: no doc, README section, script or
workflow points at it, and it describes a ten-years-old, pre-2.0
snapshot of the library.

Part of #5714

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

* Run the CBOR, MessagePack, BSON and BON8 round-trip invariants in CI

tests/src/round_trip_corpus.hpp exists so that the byte-stability
invariant the fuzzer drivers check also runs on a fixed corpus in CI,
instead of only at OSS-Fuzz. So far only the UBJSON and BJData drivers
had a matching unit test; the CBOR, MessagePack, BSON and BON8 drivers
assert the same invariant (assert(to_X(j2) == vec)) but nothing ran it
outside OSS-Fuzz.

Add "<FORMAT> round-trip invariants" test cases to unit-cbor.cpp,
unit-msgpack.cpp, unit-bson.cpp and unit-bon8.cpp, modeled on the
UBJSON case: seed j1 from the corpus (skipping values that do not
survive the format's own round trip, as the fuzzer drivers only ever
see values from_X() actually produced), then require from_X(to_X(j1))
not to throw and check to_X(j2) == to_X(j1). BSON only serializes
objects, so non-object corpus values are skipped. Update the comments
in round_trip_corpus.hpp and tests/fuzzing.md to name all six formats.

The stream-versus-contiguous check in the BON8 driver is left out, as
#5601 reworks it.

A local probe confirms no violations on the current corpus (CBOR 3849
checked, MessagePack 3909, BSON 2958, BON8 3841 - matching the counts
already recorded for this probe in the issue).

Closes #5714 item 1.

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

* Fix fuzzer driver step lists to match the checks the code performs

The header comment of six of the seven binary-format fuzzer drivers
listed an invariant the code does not check: CBOR, MessagePack, BSON
and BON8 said "assert(j1 == j2)", but the code checks byte stability,
assert(to_X(j2) == vec). UBJSON and BJData still described the old
"assert(j1 == j2/j3/j4)" byte-exact check from before PR #5494 replaced
it with a use_size/use_type-aware round trip (UBJSON) and a
value-stability check (BJData); BJData's added paragraph already
explained the new check, but the step list above it did not.

Also remove a dead branch in fuzzer-parse_bson.cpp: from_bson() is
called with allow_exceptions = true, so it throws instead of returning
a discarded value, and the "if (j1.is_discarded()) return 0;" guard
could never trigger. Drop the unused <iostream> include from all seven
drivers and <sstream> from all but fuzzer-parse_bon8.cpp, which is the
only one that uses std::istringstream.

Overlaps #5601, which edits all seven drivers in the same hunks.

Closes #5714 item 4.

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

* Silence the CMP0169 deprecation in cmake_fetch_content, fix stale guards

tests/cmake_fetch_content/project calls the single-argument
FetchContent_Populate(json) after FetchContent_Declare(), which CMake
3.30 deprecated as CMP0169. Since the project declares
cmake_minimum_required(VERSION 3.11...3.14), the policy stays unset,
so every configure with a current CMake prints the deprecation
warning. The test is kept on purpose: it is the only coverage of the
FetchContent_Populate + add_subdirectory pattern for CMake 3.11-3.13
users, which the docs still describe as supported. Explicitly set
CMP0169 to OLD, with a comment explaining why.

Also fix two stale version guards:
- tests/cmake_fetch_content/CMakeLists.txt guarded the test with
  VERSION_GREATER "3.11.0", which is dead now that tests/CMakeLists.txt
  requires CMake 3.13.
- tests/cmake_fetch_content2/CMakeLists.txt guarded with
  VERSION_GREATER "3.14.0", which skips exactly 3.14.0, the first
  version with FetchContent_MakeAvailable. Change it to
  VERSION_GREATER_EQUAL "3.14".

Verified locally: `ctest -R cmake_fetch_content` passes with CMake
4.1, and the CMP0169 deprecation warning that appeared before this
change is gone.

Closes #5714 item 5.

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

* Make the CMake integration-test wrappers consistent

The six tests/cmake_* integration-test wrappers had drifted:

- Only cmake_import and cmake_import_minver forwarded
  -A "${CMAKE_GENERATOR_PLATFORM}" to the inner configure, and none
  forwarded -T "${CMAKE_GENERATOR_TOOLSET}". The Windows workflow
  configures the outer build with -A Win32 -T ClangCL, so without
  forwarding, the inner projects of cmake_add_subdirectory,
  cmake_fetch_content, cmake_fetch_content2 and
  cmake_target_include_directories built with the generator defaults
  instead of matching the outer build's platform and toolset. Forward
  both consistently from all six wrappers.
- cmake_fetch_content and cmake_fetch_content2 passed
  -Dnlohmann_json_source to their inner projects, which never read it
  (CMake warns "manually-specified variables were not used"); the
  inner projects fetch their own copy of the library instead. Drop it.
- tests/CMakeLists.txt set JSON_FORCED_GLOBAL_COMPILE_OPTIONS from the
  matching environment variable but never read the cache variable
  again; the lines right below it read $ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS}
  directly, like the LINK_OPTIONS counterpart already does. Remove the
  dead set().

This changes which platform and toolset the Win32 and ClangCL CI jobs
build the four newly-forwarding wrappers' inner projects with, which
may surface new failures there; CI has to confirm those jobs.

Verified locally with Ninja (empty -A ""/-T "" is accepted): all 12
cmake_* tests still pass, and the inner fetch_content configures no
longer warn about the unused variable.

Closes #5714 item 6.

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

* Turn the #972 fifo_map regression test into a real test

The #972 regression test in unit-regression1.cpp only built a
my_json array from a string literal (the original crash) and had no
CHECK, so the fifo_map object type it exists to demonstrate was never
exercised. Meanwhile the docs recommend fifo_map for keeping object
keys in insertion order (object_order.md, template_parameters.md),
and nothing tested that recommendation.

Extend the section: after the original array assignment, parse an
object with my_json::parse() (not via the "..."_json UDL, which
returns a plain nlohmann::json and would exercise the cross-basic_json
conversion constructor instead of the parser's own key insertion -
and, as tried locally, does not keep fifo order for this stateful
comparator) and check that dump() keeps insertion order, and that it
survives erase() and inserting a new key.

Also narrow thirdparty/fifo_map off the include path of every other
test-* target: it was a PUBLIC include directory of test_main, even
though unit-regression1.cpp is its only user. Add a small
fifo_map_include INTERFACE library with that include directory and
attach it to test-regression1 only via json_test_set_test_options().

Verified locally (test-regression1_cpp11, default build and
-fsanitize=address,undefined): the new checks pass; `git grep fifo_map
tests` still only finds unit-regression1.cpp and the vendored header.

Closes #5714 item 7.

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

* Document the vendored doctest.h patch; fix stale doctest_compatibility.h comments

tests/thirdparty/doctest/doctest.h is doctest 2.4.12, imported in
#4771. Two weeks later, #4801 hand-edited translateActiveException()
to declare "String res;" inside the translator loop instead of before
it, so a translator that does not match does not leave a previous
translator's result in "res" for the next iteration to see. Nothing
recorded this, so re-vendoring doctest.h from upstream would silently
drop the fix. Add a comment at the patched site naming the version,
the PR and the reason, so a future re-vendor knows to re-apply it.

Also fix two stale comments in doctest_compatibility.h:
- The DOCTEST_THREAD_LOCAL comment referenced Xcode 6/7, which is no
  longer supported; reword it to explain why the define must stay
  regardless (it keeps doctest's own thread_local usage out of the way
  of the same Clang/MinGW crash that JSON_NO_THREAD_LOCAL works around
  in the library, see ci_test_no_thread_local).
- The <iosfwd> include's comment justified it with tests that define
  "private" as "public"; no test under tests/src does that any more
  (removed by #2352). Reword the comment instead of dropping the
  include, since confirming it is safe to drop needs the full CI
  matrix including MSVC 2015+.

Verified locally that tests/src/unit-readme.cpp still builds and
passes 17/17 with these headers.

Closes #5714 item 9.

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

* Stop compiling unit-wstring.cpp out entirely on classic ICC

tests/src/unit-wstring.cpp wrapped the whole file in
#ifndef __INTEL_COMPILER, with the comment "ICPC errors out on
multibyte character sequences in source files". The ci_icpc job
(intel/oneapi-hpckit:2023.2.1) still exists, so that job ran none of
the wstring/u16string/u32string input adapter tests, including the
malformed-input checks #5704 (open) extends.

Only 9 lines contained non-ASCII bytes: the three *_is_utf16()/
*_is_utf32() probe functions, and three std::wstring/u16string/
u32string literals plus their narrow-string dump() expectations.
Rewrite all of them with \u/\U escapes in the wide/u16/u32 literals
and \x escapes (split into separate string-literal tokens so a
following byte is never read as part of the same hex escape, e.g.
"\xE1\x83\x85" "a") in the narrow ones. Remove the
#ifndef __INTEL_COMPILER/#endif guard along with it.

The *_is_utf16()/*_is_utf32() probes compared a raw multibyte literal
against an escape-based one to detect a compiler that misreads the
source file's encoding; with no raw literals left to misread, the
comparison is now tautological, so drop the probes and the "if"
guards around each SECTION's body instead of leaving them in as dead
checks.

The same non-ASCII-in-source-and-in-a-narrow-comparison pattern
existed once more in unit-deserialization.cpp's "Using _json with
char8_t literals #4945" test: a raw emoji character in a u8R"(...)"
literal, guarded by a check_utf8() that returned false for ICC (same
reason) and for Windows without the active UTF-8 code page. Rewrite
the literal with a \U escape and compare it against a \x-escaped
expectation instead of a second raw literal, and drop check_utf8()
and the now-unused <windows.h> include along with the guard.

Verified locally (clang, -std=c++11 and -std=c++20,
-fsanitize=address,undefined, and a plain build): test-wstring keeps
18/18 assertions and unit-deserialization keeps 466/466 (c++11) and
477/477 (c++20) assertions, matching this branch before the change
exactly - no coverage was gained or lost, only the source-encoding
dependency was removed. ci_icpc has to confirm classic ICC actually
builds and passes test-wstring now; if it does not, that is a real
finding, not a reason to restore the guard.

Overlaps #5704 (open), which edits unit-wstring.cpp inside the
previously-guarded region (an include near the top, checks in the
invalid-string sections, and a new section at the end).

Closes #5713 item 5.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 07:33:07 +02:00
Niels Lohmann cff0a61369 Share DOM SAX position handling; fix stale parser and lexer comments (#5731) 
* Share the diagnostic-position setter of the DOM SAX parsers

json_sax_dom_parser and json_sax_dom_callback_parser each had a private
copy of handle_diagnostic_positions_for_json_value(), identical except
for comments. Move the body into one static member function,
detail::diagnostic_positions::set_from_lexer(value, lexer), which both
classes call with their lexer pointer. basic_json befriends the new
struct (only when JSON_DIAGNOSTIC_POSITIONS is enabled), as the position
members are private.

The discarded case is reached through the callback parser, so the
LCOV_EXCL markers that only the dom parser's copy had are gone. The
NOLINT on the unreachable default case loses the stray
"-warnings-as-errors", which is not a check name.

The start-position setup in start_object()/start_array() is left alone,
as #5706 is editing the callback parser's versions.

Behavior, the public API and the ABI are unchanged.

Part of #5712

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

* Correct the parser comments on recursion and skip_to_state_evaluation

The class documentation called the parser a recursive descent parser,
but sax_parse_internal() is a loop that keeps the open containers on an
explicit stack. The comment at the end of an array and of an object
said the flag is set to false while the code below it sets it to true.
Describe what the code does instead.

Comments only; behavior, the public API and the ABI are unchanged.

Part of #5712

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

* Update the discard_number_values comments to the current number path

The comments explaining the accept() shortcut in convert_number() and
the member documentation still argued in terms of strtoull()/strtoll()
and errno, which #5283 replaced with convert_integer(), and pointed at
scan_number() instead of convert_number(). They also did not say that
scan_number_bulk_contiguous() converts integers itself, so the shortcut
is only reached for input without bulk access, with
JSON_DIAGNOSTIC_POSITIONS, or when the bulk scanner falls back.

Rewrite both comments to describe the digit-count check in front of
convert_integer(), keeping the 18-digit bound and the json_sax_acceptor
argument. The stale <cstdlib> comment is left for after #5616, which
edits that include block.

Comments only; behavior, the public API and the ABI are unchanged.

Part of #5712

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

* List the UTF-8 validators instead of calling the DFA the only one

The documentation of decode() called the Hoehrmann DFA the single
source of truth for UTF-8 validation. It is used only by the serializer
and by is_valid_utf8() (CBOR/MessagePack/BSON/UBJSON/BJData text
strings). The lexer's scan_string() switch, validate_one_utf8() /
valid_utf8_prefix() (bulk string scan, BON8 bulk path and BON8 writer)
and the BON8 byte path in get_bon8_string() check the RFC 3629 ranges
on their own.

Replace the sentence with a list of the four validators, what each is
used for, and a note that they must accept the same sequences. Sharing
code between them was considered and dropped: it would save a few lines
in a validator that is entangled with BON8 pushback, and #5677 is
editing the BON8 byte path.

Comments only; behavior, the public API and the ABI are unchanged.

Part of #5712

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

* Fix stale doc comments and include lists in the input headers

input_adapters.hpp included <memory> and <numeric> for the removed
shared_ptr-based adapter design but used neither; it called
(std::min) without including <algorithm>. json_sax.hpp used
std::numeric_limits without including <limits>. Also corrected
comments that no longer matched the code: input_stream_adapter does
not skip the input's BOM (the lexer's skip_bom() does), the
span_input_adapter comment named the no-longer-existing
input_buffer_adapter type, lexer::get_string() does not reset the
token, binary_reader's get_number() doc opened with /* instead of
/*! (so Doxygen skipped it) and omitted BON8 from its endianness
note, and the UBJSON-binary-types note did not mention that BJData
'B' arrays are read as binary.

Left out: the lgtm suppression on lexer.hpp's scan_number() (in
#5616's hunk) and the "-1 if unknown" wording in json_sax.hpp's
start_object/start_array docs (in draft #5267's hunk), per the
verdict's conflict list.

Part of #5712

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

* Deduplicate the strict-EOF/release_lookahead/error block in parser::parse()

json_sax_dom_callback_parser and json_sax_dom_parser branches of
parser::parse() ran the same ~25 lines after sax_parse_internal():
the strict-mode EOF check (raising parse_error.101 through the SAX
parser), release_lookahead() in non-strict mode, and mapping an
errored SAX parser to a discarded result. The two copies had already
drifted apart in formatting and in the second copy's "see above"
comment.

Add a private parse_dom(DomSax&, strict) member that runs this shared
sequence once and returns whether the SAX parser did not error; both
branches of parse() now only construct their DOM SAX parser, call
parse_dom(), and (for the callback parser) map a discarded top-level
value to null. sax_parse() is left untouched, since it only runs the
EOF check and release_lookahead() when sax_parse_internal() succeeded,
unlike parse(), which runs them unconditionally.

Behavior-preserving: same operations in the same order for both SAX
parser kinds. Verified with unit-class_parser (strict/non-strict,
callback and non-callback), unit-deserialization and
unit-disabled_exceptions (JSON_NOEXCEPTION), plus a clean
make amalgamate / make check-amalgamation diff.

Overlaps #5601, which touches the same lines.

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

#5712 item 2

* Share the code point to UTF-8 encoding between the wide-string helpers and the lexer

The 1/2/3/4-byte UTF-8 encoding ladder was written out by hand three
times: in wide_string_input_helper<..., 4>::fill_buffer() for a UTF-32
code point, in the UTF-16 helper for both a BMP code unit and a valid
surrogate pair, and in the lexer's \uXXXX/\uXXXX\uYYYY handling. The
copies had drifted: the UTF-32 helper masked the leading bits of each
byte (& 0x1Fu, & 0x0Fu, & 0x07u) where the others relied on the shift
alone, even though both give the same result for a code point that is
already known to be in range.

Add detail::encode_utf8(cp, out) in string_utils.hpp, a single encoder
that invokes a callable once per output byte, most significant byte
first. Use it in the three valid-code-point branches (UTF-32 code
points up to U+10FFFF, UTF-16 code units outside the surrogate range,
and valid UTF-16 surrogate pairs) and in the lexer's \u handling, where
out forwards to add(). The UTF-16 helper's deliberate pass-through of
malformed surrogate units and the UTF-32 helper's 0xFF sentinel for
code points above U+10FFFF are untouched, since neither reaches the new
helper.

Behavior-preserving: same bytes in the same order for every valid code
point, verified with unit-class_lexer, unit-class_parser,
unit-deserialization, unit-wstring and the non-test-data parts of
unit-unicode1..5 (ASan/UBSan, C++11/17/20), and an escape-heavy parse
microbenchmark that shows no change (about 73 ms either way, median of
3, 1M escape sequences). single_include/ regenerated with make
amalgamate; make check-amalgamation leaves a clean tree.

Overlaps #5704, which rewrites the wide_string_input_helper
specializations touched here.

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

#5712 item 6

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 07:32:32 +02:00
Niels Lohmann 3926fcaac3 Deduplicate serializer dump code; fix stale includes, docs, and lint (#5729) 
* Share scalar serialization between dump_internal and dump_value

dump_value()'s cases for string, binary, boolean, number_integer,
number_unsigned, number_float, discarded and null were a byte-for-byte
copy of dump_internal()'s (added together in #5285 for the iterative
fallback path). Any future change to scalar output had to be made in
both places, or the recursive and depth-limited paths would silently
start producing different bytes.

Extract the shared cases into a private dump_scalar() and have both
dump_internal() and dump_value() call it. Output is unchanged: dump(),
dump(4), dump(-1,' ',true) and the replace/ignore error_handler_t
variants are byte-identical over the json_test_data corpus before and
after, and dump() throughput on a scalar-heavy document is unaffected.

Part of #5709

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

* Drop serializer.hpp's dependency on binary_writer.hpp

The only use of binary_writer in serializer.hpp was
binary_writer<BasicJsonType, char>::to_char_type() to write the
U+FFFD replacement character's three bytes. With CharType=char this
is an identity conversion, so the include of binary_writer.hpp (and
transitively binary_reader.hpp) pulled in a large, unrelated header
for a no-op call.

Write the three bytes directly instead. serializer.hpp compiles
standalone with -Wall -Wextra -Werror, with and without
-funsigned-char, and unit-serialization's error_handler_t::replace
cases (with and without ensure_ascii) still pass. Moving
binary_writer's to_char_type/to_msgpack_length to its private section
is left as an optional follow-up.

Part of #5709

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

* Fix stale #include lines in the output headers

output_adapters.hpp included <algorithm> and <iterator> for std::copy
and std::back_inserter, which have not been used there since #3569
(2022). serializer.hpp included <algorithm> for std::reverse (also
unused), <cmath> for labs/isnan/signbit (only std::isfinite is used)
and <utility> for std::move (nothing from <utility> is used there),
while using std::next without including <iterator> at all, relying on
getting it transitively through output_adapters.hpp's own stale
<iterator>.

Drop the unused includes, add <iterator> for std::next, and correct
the remaining include comments. Both headers still compile standalone
with -Wall -Wextra -Werror.

Part of #5709

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

* Remove JSON_HEDLEY_NON_NULL(2) from write_characters() overrides

output_vector_adapter, output_stream_adapter and output_string_adapter
declared their write_characters(const CharType*, std::size_t) override
JSON_HEDLEY_NON_NULL(2), but binary_writer legitimately calls it with
a null pointer and length 0 for an empty string or binary value; the
type-erased call path only stayed silent under UBSan because the
static callee at those call sites is the unattributed virtual base.
A nonnull attribute on a definition lets GCC and Clang assume the
parameter is non-null inside the function body even when the call is
virtual, so this was latent undefined behavior, not just style.

Drop the attribute from the three overrides and document the
(nullptr, 0) contract on output_adapter_protocol::write_characters.
unit-cbor, unit-msgpack, unit-bson and unit-bon8 (which all exercise
empty binary/string payloads through the stream and vector/string
adapters) pass under -fsanitize=address,undefined,nonnull-attribute.

Part of #5709

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

* Update stale serializer doc comments to match the current implementation

dump_internal()'s doc block still described the pre-#5285/#5449
implementation: an escape_string() function that does not exist
(the function is dump_escaped), integer conversion "implicitly via
operator<<" (dump_integer actually uses a digit-pair lookup table),
and floating-point conversion via "%g" (IEEE-754 types go through
to_chars, others through snprintf). dump_value()'s comment said
elements are pushed for dump_internal to walk, but it is
dump_iteratively() that walks the stack. dump_escaped(), dump_integer()
and dump_float() each said they write "to output stream @a o", which
has not been true since the writer moved to write_buffer.

Doc-only change; no behavior, API or ABI impact.

Part of #5709

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

* Merge duplicate byte-to-hex helper and drop stale '| 0' promotions

serializer::hex_bytes() and binary_writer::hex_byte() had identical
bodies. Keep one, detail::hex_byte() in string_utils.hpp, and use it
from both. Also drop the `| 0` at the two serializer call sites
(hex_bytes(byte | 0) and hex_bytes(s.back() | 0)): #3088 (7440786b8)
added it so that `ss << std::hex << (byte | 0)` printed a number
rather than a char with the old stringstream writer; the int result
just narrows back to uint8_t now, so it was a no-op.

Behavior is unchanged: unit-serialization, unit-bon8 (whose
type_error.316 messages exercise this code) and unit-diagnostics
pass, and both headers still compile standalone with -Werror.

Part of #5709

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

* Trim two stale lint suppressions in serializer.hpp

dump_integer()'s `auto buffer_ptr = number_buffer.begin();` carried
NOLINT entries for cppcoreguidelines-pro-type-vararg and hicpp-vararg,
left over from the snprintf-based implementation (#3088); there is no
variadic call on that line, so keep only the qualified-auto
suppressions it actually needs. remove_sign()'s assert checked
`x < 0 && x < (std::numeric_limits<number_integer_t>::max)()) `with a
NOLINT(misc-redundant-expression) to hide it; the second conjunct is
always true once x < 0, and has been since 6ce2f35ba (2019), so
reduce the assert to `x < 0` and drop the suppression instead of
masking it.

Both are documentation-only changes to assertions/suppressions, not
behavior. The to_chars.hpp `#if 0` branch this item also flagged is
left alone, next to draft PR #5634's pending hunk.

Part of #5709

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

* Move the Hoehrmann SPDX copyright line to string_utils.hpp

serializer.hpp carried the SPDX-FileCopyrightText line for Björn
Hoehrmann's UTF-8 decoder, but the decoder (decode() and the utf8d
table) has lived in string_utils.hpp since #5185 (d19f7f5dc);
serializer.hpp now only calls decode(). Move the copyright line to
where the code it covers actually is.

Part of #5709

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

* Stop calling std::localeconv() on every dump()

The serializer constructor snapshotted std::localeconv() into a
locale_chars member on every dump(), even though the only reader is
dump_float(number_float_t, std::false_type)'s snprintf path, taken
only for a number_float_t that is neither IEEE single nor double.
localeconv() is not required to be thread-safe with setlocale(), so
every dump() paid for and raced on a lookup that almost never mattered.

Remove locale_chars and the locale member. Right before the
thousands-separator/decimal-point fixups in the snprintf path, read
std::localeconv() into local thousands_sep/decimal_point variables
(null-checked, first byte only, as before) - the same way
lexer::get_decimal_point() already does since #5597. Output is
unchanged unless the locale changes during a single dump(); in that
case the fixups now match what snprintf just produced, instead of a
value snapshotted before the call.

Overlaps draft PR #5608, which touches the same constructor and
dump_float() lines to move this code into a new
dump_float_snprintf(); this lands the lookup change now as #5709 asks,
and #5608 can do the lookup inside dump_float_snprintf() when it
rebases.

Verification: the full json_test_data corpus (742 files, dump(),
dump(4) and dump(-1,' ',true)) is byte-identical to before the change
under the C locale. Added a test pinning the new per-conversion
lookup: it switches LC_NUMERIC mid-dump() (via a streambuf that
switches on its first write, after the serializer's write buffer has
been flushed once but before a later float is converted) and checks
the decimal point is still normalized using the locale active at
conversion time. On a platform where long double is IEEE-754 double
(e.g. 64-bit Arm), dump_float() takes the locale-independent
to_chars() path and the test is a no-op there; it is meaningful on a
platform where long double is extended precision (most x86 targets).

Part of #5709 item 3

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-10-01 07:31:42 +02:00