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Niels Lohmann 5bdeffac10 docs: blog post: remeasure on develop with #6029, #6031, #6033 and #6039 
Rerun on develop 7fc8312c64 with the open pull requests #6029, #6031,
#6033 and #6039 merged, measured on November 7: the suite (median of 12
runs, now 3.3x), the timeline (358 commits, #6031 shown as a pending
step on the candidate, #6028 labeled, a tick for November), the compile
times, the stream gap, the allocator check and the comparison on the
Mac and on x86-64, including the held-out files.

The comparison now leaves out the "copy untimed" variants, as the post
describes, and the held-out chart no longer counts json::accept() as
another library. Appendix D, the Intel column of Appendix B and the
GCC 16/Clang 23 check on the Mac are still from November 3.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-09 08:11:14 +01:00
Niels Lohmann c0cb0e1bb3 docs: blog post: describe the performance work of #6020, #6028-#6031 and #6033 
Theme 1 gets the iterator pairs of std::string and std::vector, a new
subsection on the fused contiguous parser after yyjson's reader, and the
FILE buffer window after gnulib's freadptr(). Theme 2 shows the reduced
SWAR test and the (c ^ 2) < 33 vector compare. Themes 4 and 6 get the
binary strings without a zero fill and the 64 KiB window of the vector
sink. Appendices H and J list the new pull requests and their checks.

The numbers of the suite, the timeline, the comparison and the compile
times are not remeasured yet.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-09 08:11:14 +01:00
Niels Lohmann 2c7474affc docs: add the blog post "How nlohmann/json 3.13.0 got 3× faster" (#6022) 
* docs: add the blog post "How 3.13.0 got faster"

A post for the documentation (Home > Blog) on how 3.13.0 became faster:
eight themes with the pull requests behind them, the ideas taken from other
libraries, what did not work, how the fast paths are tested, and the
compile-time cost. Every number comes from a run on 2026-10-27 (3.12.0 against
develop plus the open non-draft PRs, Apple M1 Max) or from the linked PR.

- docs/mkdocs/docs/home/blog/how_3_13_0_got_faster.md: the post.
- docs/mkdocs/scripts/figures/perf_blog.py: draws its 12 figures (overview,
  eight timeline panels, the SWAR test, the cliffs, json_view throughput) as
  inline SVGs in the nj-charts style; data/perf_timeline.csv holds the
  timeline.
- tests/benchmarks/history: history.cpp and history.py time one fixed program
  against the header of every commit that changed it, interleaved, and write
  one CSV row per commit with its PR. The timeline of the post comes from it.

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

* docs: compare json_document with Glaze, sonic, RapidJSON and Rust parsers

Extends the comparison in "How 3.13.0 got faster" from yyjson, simdjson and
Boost.JSON to eleven engines: sonic-cpp, RapidJSON and Glaze (generic DOM,
lazy_json, reading into structs) in C++, sonic-rs, simd-json and serde_json in
Rust. Measured on an Apple M1 Max (Apple clang 21, Rust 1.99) and an x86-64
Haswell server (GCC 13, Clang 18). Every engine must return the same values,
string bytes and bit-identical number sums before it is timed.

The post now answers whether json_document is the fastest parser: it is the
fastest document parser at parse+dump everywhere and at parsing on Apple
silicon, ties with simdjson's DOM on x86-64, and loses to simdjson On-Demand
and Glaze structs when only a few fields are read.

tests/benchmarks/json_view/others holds the programs (bench_all.cpp, the Rust
crate with its Cargo.lock), summarize.py and the pinned versions and checksums.

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

* docs: captions, test-file table and figure fixes for the 3.13.0 post

- caption every table and figure
- describe what makes twitter.json, citm_catalog.json, canada.json and
  jeopardy.json hard, and what each timeline panel exercises
- split the json_view layout figure into the tree and the index, with
  the example text above; fix the arrows into the string boxes
- arrows and a "less is better" axis label in the cliffs figure
- name nlohmann/json in the comparison tables and chart
- licenses of the adapted code in the thanks section

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

* docs: byline and licenses for the 3.13.0 post

- author and date below the title, styled as .nj-byline; its link gets
  no external-link icon
- the license of every library in the thanks section, checked against
  each project's license files; credit sonic-rs for QUOTE_TAB, which
  orjson adapted from it

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

* docs: dump comparison and split acknowledgments in the 3.13.0 post

- a dump workload in bench_all and bench_rs: each engine writes a
  document parsed beforehand, and every output must read back with
  bit-identical numbers; an optional argument selects one workload
- the post's comparison gains a write table, a throughput chart, a dump
  row for all three configurations, and the x86-64 cases it loses
- the thanks section is split into adapted code and borrowed ideas

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

* docs: x86-64 dump numbers with #5908's branch-free token digits

The dump of canada.json with GCC on x86-64 lost to yyjson by 0.78 because
GCC compiled #5908's token-digit selections as branches; 9fad526888 fixed
that. The post's x86-64 dump and parse+dump rows of canada.json are now
measured with it (GCC 0.95, Clang 0.91 against yyjson), theme 5 tells the
story, and "How we measured" says which rows include the commit.

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

* Compare JSON libraries by use case in the json_view harness

bench_all and bench_rs now time use cases (validate, sum, select, edit,
minify, write) instead of library functions. Every library may solve a
use case in every way it offers; each variant's result is checked, and
three malformed inputs give its validation level (full, no UTF-8,
partial). summarize.py reports each library's fastest fully validating
variant and a faster one at a lower level, as text and as JSON.

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

* docs: restructure the 3.13.0 post around themes and use cases

- deeper technical detail and code in the eight themes; pull request
  numbers move to the appendix, timeline steps are labelled by theme
- comparison with other libraries by use case, as heatmaps per
  platform, with validation levels and the caveats next to the results
- appendix: test files, all 182 suite rows with a histogram, timeline
  steps, algorithmic fixes, per-file tables, behaviour changes, setup,
  pull requests by theme

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

* Measure each library's fastest modes in the json_view harness

Address the points of a review from the other libraries' side:

- simdjson 5.0.8 (On-Demand structs, key selectors) and Glaze 9.1.0
- number-skipping modes: yyjson and RapidJSON raw numbers, Boost.JSON
  number_precision::none
- reused parsers and allocators for yyjson, RapidJSON and Boost.JSON
- Boost.JSON parse_into, Glaze generic with double numbers, and the
  same struct types for nlohmann, Glaze, simdjson and serde
- minified copies of twitter.json and citm_catalog.json
- a fourth probe (trailing garbage) and Glaze "(strict)" variants
- a new random variant order in every round, as a variant's time could
  depend on the one before it by up to 15 % on the Mac
- --files for other test files and --conformance for JSONTestSuite,
  with conformance-rs.sh for the Rust program

summarize.py also reports each library's best reused variant.

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

* docs: rerun the library comparison of the 3.13.0 post with fairer rules

The figures and Appendix E use the reruns with each library's fastest
modes. Skipping number conversion while reading is now allowed for
every library; copying number text is still not chosen when writing.

The text now says who set the rules, where libraries that check less
win select, how minified files change the picture, and that the
reused jeopardy.json claim holds with every library reused. A new
section covers 19 held-out files and JSONTestSuite, including where
json_document loses, and lists what was not measured. Every
comparison number was recomputed; Glaze is credited in the intro.

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

* docs: measure the 3.13.0 post against develop with #5964 and #5908

The suite (Appendix B, the short-version table, the overview and distribution
figures) and the timeline endpoint now measure develop d20c4dcd89 with #5964
and #5908 merged. The geometric mean stays 2.9x (2.95); Dump/signed_ints and
Dump/unsigned_ints gain 1.5x and 2.1x from #5964; GetVectorDouble/floats drops
from 10.3x to 7.0x because the old candidate's suite binary happened to compile
that loop faster (a standalone build takes 0.97 ms with both headers).

The timeline endpoint is the 10-27 value scaled by the ratio of the new to the
old candidate, both measured on 10-30, so that it stays comparable with the
other points of the timeline.

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

* docs: add three figures to the 3.13.0 post

- short strings: two overlapping 16-byte loads and stores
- eight digits at a time: the three multiplications, lane by lane
- validate on the 19 held-out files, per file, Mac and x86-64

The prose the figures replace is trimmed.

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

* docs: measure the 3.13.0 post against develop with all open pull requests

The baseline is now develop 9c349b1d7c with every open non-draft pull
request merged, including #5968, #5970, #5971, #5975, #5976, #5978,
#5979, #5980, #5981 and #5982. The suite was rerun on 11-01 with every
step repeated when the load rose above 5 while it ran; the comparison
with other libraries and the held-out files were rerun on 10-31.

- suite: 3.0x geometric mean (median 2.9x); Appendix B, the overview
  and the distribution regenerated
- timeline endpoint, Appendix D and the cliffs figure updated
- the held-out figure compares json_document with the fastest other
  library
- new paragraphs for the pull requests listed above

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

* docs: measure the 3.13.0 post against develop with the open pull requests of 11-02

Suite, timeline endpoint, Appendix D and the scalar-run numbers now come from
develop b2674a4a2f with #5990, #5991, #5992, #5996, #5997, #5998, #5999 and
#6000 merged. The scalar runs are measured against a build without them on
develop's code, which no longer checks for a scalar before entering the loop.

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

* docs: measure the 3.13.0 post against develop with all open pull requests of 11-02

Suite, timeline endpoint, Appendix D and the scalar-run numbers now come from
develop b2674a4a2f with #5990-#5992, #5996-#6006 and #6008 merged. With #6008,
arrays of one element skip the scalar run, so nested arrays no longer pay for
it. The suite ran three rounds per version; the round of 3.12.0 and of 3.13.0
that differed from the other two was dropped, as the setup table says.

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

* docs: fix the facts the review of the 3.13.0 post found wrong or imprecise

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

* docs: re-measure the 3.13.0 post and apply the review

Measure everything again against develop with the open pull requests of
11-03 (suite, timeline, comparison on the Mac and on x86-64, compile
times, stream gap), add the suite on an Intel MacBook Pro as a check,
mark the ways that keep number text as "N" in the use-case charts, move
the loop-shape box to theme 5, and apply the style and wording fixes of
the review.

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

* docs: make the comparison of the 3.13.0 post fairer

Three reviews of "How it compares" (a maintainer audit of the harness, a
methodology review, a reader's red team) led to a full rerun on the Mac and
x86-64 with simdjson 5.1.1 and new ways in the harness:

- in-place parses with the copy made before the timer ("(copy untimed)",
  never chosen as a library's best) and json_document::parse_copy();
- RapidJSON through StringStream, and with default precision in validate,
  which reads no number;
- BENCH_ONLY takes several prefixes.

The post now gives the copy's real cost (11-14 us for twitter.json on the
Mac, not 30), what yyjson gains without it, the run-to-run noise, the LTO
check, the single-file losses that were missing, and qualifies the headline
claim. Every number in the section and Appendix E is recomputed; the
NUL-byte remark moved out of the body.

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

* Format bench_all.cpp with astyle

The amalgamation check runs astyle over tests/ and failed on bench_all.cpp. The variant tables keep one variant per
line between *INDENT-OFF* and *INDENT-ON*; astyle formats the rest, and the list of use cases becomes a named array so
the loop header stays on one line.

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

* Print the history benchmark's results with a stream

Flawfinder flagged the printf in history.cpp (CWE-134), although its format string is a constant. The stream prints the
same text, so history.py reads it as before.

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

* docs: address review comments on the performance blog post

- fix wording: "are new", "for each input source", "the strings", "the last zero to seven bytes", "by" Danila
  Kutenin, "the result of that query"
- introduce `json_document` where it first gets a detail, say that the `-mbranches` flag is not used, explain
  why the position and token bookkeeping overloads are empty, and say that a step's percentage is relative to
  the time before the step and that a median of 4 is the mean of the two middle values
- write percentages without a space before `%` in the post and in the price figure (regenerated)

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

* docs: wrap the prose of the performance blog post at 120 columns

Only line breaks change: the rendered page is identical after whitespace normalization.

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

* docs: blog post: address the second round of review comments

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

* docs: blog post: note that Boost.JSON's tree lead comes from its arena

The comparison builds Boost.JSON's tree in a monotonic_resource. With its
default allocator and precise numbers, boost::json::parse() takes as long
as json::parse() on twitter.json, 5% longer on citm_catalog.json and 17%
less time on canada.json (M1, C++23 -O3, best of 3 x 30 runs; the arena
saves Boost.JSON 28-41%).

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

* docs: blog post: comparing already passes the depth; copying measured slower without the counter

operator== walks the standard containers itself and passes the depth as an
argument (#5840). A copy that does the same, inserting element by element,
measured 4-16% slower on an M1 Max with Apple clang, so copying keeps the
thread_local counter.

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

* docs: blog post: name every user of the depth counter and every input the document copies

The "Bounded recursion" paragraph said only copying and equality for custom
containers use the thread_local counter. Converting from another basic_json
specialization and the ordering comparisons use it too; equality for the
standard containers passes the depth instead.

The "Strings stay in the input" bullet named only parse_copy() and an rvalue
std::string as owning inputs. Streams, FILE* and other input that is not one
contiguous block of bytes are read into an owned buffer as well.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-09 08:11:10 +01:00
dependabot[bot] 6343775000 build(deps): bump reuse from 6.2.0 to 6.3.0 in /cmake/requirements (#6035) 
Bumps [reuse](https://github.com/RichardLitt/standard-readme) from 6.2.0 to 6.3.0.
- [Release notes](https://github.com/RichardLitt/standard-readme/releases)
- [Commits](https://github.com/RichardLitt/standard-readme/commits)

---
updated-dependencies:
- dependency-name: reuse
  dependency-version: 6.3.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
 2026-11-09 08:10:36 +01:00
Niels Lohmann 7fc8312c64 Fix ci_test_clang_sanitizer: build the CBOR test string from bytes (#6037) 2026-11-07 14:27:52 +01:00
Niels LohmannandClaude Sonnet 5.5 18138227dc Scan the buffer of a FILE in bulk with glibc and the Apple C library (#6030) 
* Scan the buffer of a FILE in bulk with glibc and the Apple C library

Parsing from a FILE* still read one character at a time through
getc_unlocked(), while a std::istream has its get area scanned in bulk.
file_input_adapter now offers the lexer the same kind of window into the
buffer of the FILE: it reads the fields that the C library's own
getc_unlocked() macro reads (glibc: _IO_read_ptr and _IO_read_end; Apple:
_p and _r) and consumes exactly the characters getc_unlocked() would
return, so the file is left where it was left before. The part of the
current token in a buffer that is about to be refilled is kept for error
messages, as for streams. The window needs the file locked for the whole
parse, so JSON_DISABLE_UNLOCKED_FILE_IO and MemorySanitizer builds turn it
off; uClibc, which defines __GLIBC__ but has other fields, does not get it.

parse() from a FILE* gets 2.0-2.6x as fast on an Apple M1 Max and 1.7-2.2x
on x86-64 (glibc, GCC 15 and Clang 21), accept() 2.9-4.4x; that is about as
fast as parsing from a std::ifstream. The new tests read with FILE buffers
of 1 to 70 bytes and unbuffered files, after ungetc(), with SAX positions
and with binary strings across the buffer's edges.

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

* Tests: no setvbuf() buffer below 2 bytes on Windows

The Microsoft C runtime rejects a _IOFBF buffer size below 2 as an
invalid parameter and ends the process (0xc0000409), which made
test-file_input fail on all MSVC and clang-cl jobs.

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

* Fix CI: astyle formatting in unit-file_input.cpp

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

* Tests: limit the multi-character ungetc() test to glibc and Apple

The Windows C runtime only supports one pushed-back character, which
broke the Windows CI jobs.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasEsrzHhSNouxSoEwqz
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Tests: sweep_allocator::construct() accepts pointers to const

Recent libc++ (emsdk latest) probes construct(const T*, const T&) in an
unevaluated context while checking for trivial copies; the static_cast to
void* in the noexcept specification then fails to compile.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasEsrzHhSNouxSoEwqz
(cherry picked from commit 794bf70823c12a2a1cb2a8a95f34dfb6357746a8)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Tests: guard sweep_allocator::construct() against const types instead of const_cast

The const_cast added in the previous commit is rejected by
cppcoreguidelines-pro-type-const-cast (clang-tidy). Make construct() not
viable for const U instead, which is what libc++ probes for.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasEsrzHhSNouxSoEwqz
(cherry picked from commit de099fa607001b710862fd1bbecef3609c54cbc4)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Fix CI: astyle and clang-tidy for sweep_allocator::construct()

astyle 3.4.13 reformats the enable_if<!...> default template argument
(Check amalgamation). Delete the const overload instead, which makes the
libc++ probe for const objects fail in the SFINAE context just the same
and needs no <type_traits>.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasEsrzHhSNouxSoEwqz
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Co-authored-by: Claude Sonnet 5.5 <noreply@anthropic.com>
 2026-11-07 10:11:09 +01:00
Niels LohmannandClaude Sonnet 5.5 951271127b Binary readers: append strings straight from contiguous input (#6028) 
* Binary readers: append strings straight from contiguous input

get_bytes() read every string into a zero-filled resize() and copied the
bytes over it, so each byte was written twice. A string that the input holds
in one block (bulk_remaining() at least its length) is now appended from it
directly. The claimed length is checked against the input first, so a huge
claimed length still allocates nothing it cannot fill; other inputs and
binary values keep the chunked loop.

from_cbor() and from_msgpack() of twitter.json and citm_catalog.json get
5.5-9.1% faster on an Apple M1 Max and 2.7-8.6% on x86-64 (GCC 15, Clang 21);
canada.json, which has few strings, is unchanged.

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

* Binary readers: keep the tag argument of append_from_block() astyle-proof

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

* Fix CI: bugprone-signed-char-misuse in append_from_block

Convert the (positive) length to its unsigned type before widening it
to std::size_t, as clang-tidy flags the int8_t to std::size_t cast.

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

* Tests: sweep_allocator::construct() accepts pointers to const

Recent libc++ (emsdk latest) probes construct(const T*, const T&) in an
unevaluated context while checking for trivial copies; the static_cast to
void* in the noexcept specification then fails to compile.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasEsrzHhSNouxSoEwqz
(cherry picked from commit 794bf70823c12a2a1cb2a8a95f34dfb6357746a8)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Tests: guard sweep_allocator::construct() against const types instead of const_cast

The const_cast added in the previous commit is rejected by
cppcoreguidelines-pro-type-const-cast (clang-tidy). Make construct() not
viable for const U instead, which is what libc++ probes for.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasEsrzHhSNouxSoEwqz
(cherry picked from commit de099fa607001b710862fd1bbecef3609c54cbc4)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Fix CI: astyle and clang-tidy for sweep_allocator::construct()

astyle 3.4.13 reformats the enable_if<!...> default template argument
(Check amalgamation). Delete the const overload instead, which makes the
libc++ probe for const objects fail in the SFINAE context just the same
and needs no <type_traits>.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasEsrzHhSNouxSoEwqz
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Co-authored-by: Claude Sonnet 5.5 <noreply@anthropic.com>
 2026-11-07 10:10:50 +01:00
Niels LohmannandClaude Sonnet 5.5 cbb9e14889 Fix ci_emscripten: make sweep_allocator::construct() not viable for const types (#6036) 
* Tests: make sweep_allocator::construct() not viable for const types

The newest libc++ (emsdk latest, used by ci_emscripten) probes
construct(const T*, const T&) in an unevaluated context while checking
whether copies are trivial. For the test allocator, instantiating the
noexcept specification then fails to compile, because static_cast<void*>
cannot drop the const qualifier. Constrain construct() to non-const types,
which makes the probe fail in the SFINAE context instead of with a hard
error.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasEsrzHhSNouxSoEwqz
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Fix CI: astyle and clang-tidy for sweep_allocator::construct()

astyle 3.4.13 reformats the enable_if<!...> default template argument
(Check amalgamation). Delete the const overload instead, which makes the
libc++ probe for const objects fail in the SFINAE context just the same
and needs no <type_traits>.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasEsrzHhSNouxSoEwqz
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Co-authored-by: Claude Sonnet 5.5 <noreply@anthropic.com>
 2026-11-07 10:10:21 +01:00
Niels Lohmann b54267d2a7 Docs: compile times of JSON_HAS_STD_FORMAT=0 and JSON_HAS_RANGES=0 (#6025) 
Add sections on switching off std::format and ranges support to the
compile-times page, with measurements (Apple clang, GCC 16, -std=c++20),
the functionality that is lost, and chart rows (issue #5294).

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-05 16:04:39 +01:00
Niels Lohmann e48800f09d Binary reader and writer: remove checks that invariants make dead (#6001) 
* Binary reader and writer: remove checks that invariants make dead

Branch coverage of the test suite and of 24k mutated inputs showed
these conditions as never taken; each is implied by a check made
earlier on the same path:

- check_bson_document_size: `document_size < 0` (the size was rejected
  below 5 before it was stored)
- get_ubjson_ndarray_size: `second != 'N'` ('N' is rejected as a type
  marker before `second` can be set)
- bjd_type_name() == nullptr for an ndarray dtype: every marker
  is_valid_optimized_type() accepts for BJData has a name (now an assert)
- the early is_bjd_excluded_optimized_type() check in
  get_ubjson_size_type(): is_valid_optimized_type() rejects the same
  eight markers with the same error
- `input_format == bjdata` next to `is_ndarray`, bit 8 of the type, or a
  'B'/'u'/'m'/'M' marker: these only arise for BJData
- `first != npos` next to bit 8: the bit is only set after a count
- MessagePack writer: the `<= max` halves of the negative int8/16/32
  ladder (the ladder is in the `else` of `n >= 0`)

No change in behaviour: a build that aborts on each removed side passes
the test suite and the fuzz corpora, and a 1.6M-input differential run
of the reader against the original headers found no difference.

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

* Remove is_bjd_excluded_optimized_type(), which has no caller left; fix two comments

is_valid_optimized_type() rejects the markers BJData excludes, so the reader
no longer needs its own list; the test now checks is_valid_optimized_type()
of a BJData reader against the writer's list. The BSON size comment now says
that open_bson_document() rejects a size below 5.

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

* Make the BJData reader in the lookup test const (misc-const-correctness)

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-04 23:42:17 +01:00
dependabot[bot] 20fe34ceeb build(deps): bump lukka/get-cmake from 4.4.4 to 4.4.5 (#6024) 
Bumps [lukka/get-cmake](https://github.com/lukka/get-cmake) from 4.4.4 to 4.4.5.
- [Release notes](https://github.com/lukka/get-cmake/releases)
- [Changelog](https://github.com/lukka/get-cmake/blob/main/RELEASE_PROCESS.md)
- [Commits](https://github.com/lukka/get-cmake/compare/a89e43e22a96abafcd7a62db652a65ecd33052c9...f86dd60acae0d132056913e248bdabf0e0580b7a)

---
updated-dependencies:
- dependency-name: lukka/get-cmake
  dependency-version: 4.4.5
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
 2026-11-04 23:38:57 +01:00
Christoph Grüninger 1da8735154 Fix leak and crash when an allocation throws during parsing (#6023) 
json_sax_dom_parser::insert_key_with_index: own the new object_key_index
in a unique_ptr before key_indexes may reallocate; a throwing reallocation
leaked it.

Signed-off-by: Christoph Grüninger <foss@grueninger.de>
 2026-11-04 23:38:47 +01:00
Niels Lohmann a49242f088 Docs: reading and writing files; patch_inplace() is not atomic (#6017) 2026-11-04 17:46:20 +01:00
Niels Lohmann 42825fba07 Binary writers: zero only a window ahead of the vector sink's position (#6020) 
output_vector_sink grew the vector by resizing it to its whole new
capacity. resize() zeroes the characters it adds, so every doubling
zeroed megabytes of a fresh allocation at once: that faults in all its
pages and evicts them from the cache before the writer reaches them,
and the writer's stores then miss again. The sink now reserves the same
capacity as before but resizes the vector only to 64 KiB
(vector_sink_window) ahead of the position, which is still cached when
the writer's stores come.

to_cbor(), to_msgpack(), to_ubjson(), to_bjdata() and to_bon8() of an
array of one million numbers into a fresh vector: 4-26 % faster on x86
(Skylake laptop with Apple clang 13, Haswell VPS with GCC 16 and
Clang 23), 1-2.5 % on Apple M1 Max; other documents unchanged (within
0.4 % in reruns). The capacity and growth of the vector are as before.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-04 17:13:25 +01:00
Niels Lohmann efc437ef6e UBJSON/BJData/MessagePack reader: reject a container count equal to SIZE_MAX (#6002) 
* UBJSON/BJData reader: reject a container count equal to SIZE_MAX

The reader marks a container whose count is not known by npos, which
is SIZE_MAX. A count of exactly that value was stored unchanged and
then read as "no count", so the BJData input

    [ # M ff ff ff ff ff ff ff ff i 01 ]

parsed as [1] instead of throwing out_of_range.408 as a count of
2^64-2 does. Where size_t is 32 bits, the same holds for 'm' and 'L'
counts of 2^32-1, in UBJSON too.

The counts of 'm', 'M' and the signed types now go through
store_ubjson_count(), which rejects npos with "integer value overflow"
(the message a count beyond size_t already gets), as the CBOR reader
does in get_cbor_container_size(). An ND-array dimension of 2^64-1 gets
the same message now, where it was "excessive ndarray size caused
overflow" (the product check) on 64-bit platforms.

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

* MessagePack reader: reject an array/map 32 length equal to SIZE_MAX

On a platform with a 32-bit std::size_t, an array 32 or map 32 length of
0xFFFFFFFF equals unknown_size(), so start_array()/start_object() were
told the size was unknown and skipped the max_size() check. Route both
through the CBOR length check, renamed get_container_size(), which
already rejects that value.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-04 17:13:16 +01:00
Niels Lohmann 57b898ef99 Replace a multibyte decimal point in dump() of a long double (#5998) 2026-11-03 19:17:41 +01:00
dependabot[bot] 92707f43f2 build(deps): bump step-security/harden-runner from 2.22.2 to 2.22.3 (#6021) 2026-11-03 19:17:27 +01:00
Niels Lohmann e32051125f Fix the build of develop: tests from #5997 and #5991 (#6019) 
* Fix the build of develop: tests from #5997 and #5991

- unit-msgpack-cpp17: assign the result of json::parse in
  CHECK_THROWS_WITH_AS (GCC -Werror=unused-result)
- unit-json_view: failing_allocator::allocate is [[noreturn]]
  (clang -Wmissing-noreturn)
- unit-class_lexer: build the quoted string once
  (clang-tidy performance-inefficient-string-concatenation)
- unit-allocator: sweep_allocator provides pointer, reference and size
  typedefs, which GCC 4.8's std::map takes from the allocator
- unit-allocator: skip the "sax_parse into an existing value" sweep with
  iterator debugging, like the parser callback sweep: MSVC's std::vector
  default constructor is noexcept but allocates its debug proxy through
  the allocator, so a failing allocation in create<array_t>() terminates

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

* Fix the remaining CI failures of the tests from #5997 and #5991

- unit-custom-object-key-type: drop the redundant member initializer and
  return a braced init list (clang-tidy); direct-initialize the converted
  value, as copy-initialization makes GCC 4.8 instantiate the copy
  constructor, which needs a range constructor strict_object lacks
- unit-stream-bulk-scan: pick the claimed get area size by tag dispatch
  instead of a constant condition (MSVC C4127)
- unit-allocator: skip the parser callback and sax_parse sweeps with
  Clang 3.4 and 3.5, which leak memory when an element constructor throws
  inside a libstdc++ std::map copy or std::vector reallocation

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

* Fix the CI failures that the first failing TU of each job hid

- unit-stream-bulk-scan: compute the claimed size without a condition;
  the tag-dispatched template was unused with a 64-bit std::size_t
  (-Wunused-template)
- unit-json_view: give failing_allocator the typedefs, rebind and
  members that GCC 4.8's std::map takes from the allocator directly
- clang-tidy hits in the tests from #5997: raw string literals
  (unit-json_view), redundant c_str() and a NOLINT for &text[0]
  (unit-locale-cpp), reserve() before a loop (unit-ordered_json), and a
  NOLINT for a return that a braced list would turn into an array
  (unit-regression1)

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

* Skip the 3 GiB get-area test with a 32-bit std::size_t in the preprocessor

The claimed size was a constant 0 on Win32, so `claimed == 0 || ...` was a
constant condition and MSVC reported C4127. Guard the section with
`#if SIZE_MAX > UINT32_MAX` instead, as unit-msgpack-custom-types.cpp does.

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

* Silence modernize-use-transparent-functors for failing_map in unit-json_view

std::less<> needs C++14, and the test is also built as C++11.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-03 13:42:46 +01:00
Niels Lohmann baba5db36f Fix the MSVC and GCC builds of develop (C4127, -Weffc++) (#6016) 
json_view number(): #6006 folded the check of the digit after a minus
sign into `else if (!negative || ...)`, which MSVC 19.44 reports as
C4127 (conditional expression is constant) and /WX turns into an
error in every MSVC and clang-cl job. The check now sits in the
`if (negative)` block, right after the sign is skipped; the error and
its position are unchanged.

unit-locale-cpp.cpp: the locale_switching_token added in #5997 held a
`const char*`, so GCC's -Weffc++ asked for a copy constructor and copy
assignment. The locale name is now a std::string.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-02 20:07:00 +01:00
Niels Lohmann 07876e2292 json_view: a value that is not found has no bytes in its exception context (#6015) 2026-11-02 19:11:07 +01:00
Niels Lohmann b18b6fc7e6 Build the parser's syntax error prefix with one concat() (#6013) 
Since #6004 made the "while parsing" part unconditional, the three appends
at the start of exception_message() are one fixed string around the
context. Review follow-up to #6004.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-02 18:27:08 +01:00
Niels Lohmann 6d5581c4e8 CBOR/MessagePack readers: leave one-element arrays to the general path (#6008) 
enter_cbor_array and enter_msgpack_array called the out-of-line scalar
run for every non-empty array. When the array's element is an object or
an array, as on every level of [[...]] or the single ring of a GeoJSON
polygon, the call reads nothing; it made 1,000 arrays nested in each
other cost 4 % more instructions (GCC 13) and up to 8 % more time (Apple
clang) than without the run. #5975 had fixed that with an inline
pre-check, which was later dropped after measuring canada only.

The run is now entered only for arrays of two or more elements: the same
comparison as before, so no other row changes. Arrays of one scalar,
which the run read faster, now take the general path; they are rare in
documents (one in citm_catalog, none in twitter or canada). The new
benchmark FromBinaryShape/singles measures them, next to
FromBinaryShape/nested.

Instructions per repetition, new/old, GCC 13 callgrind: nested arrays
0.973 (CBOR) and 0.971 (MessagePack), arrays of one scalar 1.037 and
1.021, every other row within 0.15 %.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-02 18:25:44 +01:00
Niels LohmannandClaude 590b622d48 parse(): propagate std::bad_alloc instead of crashing on a half-constructed member (#5991) 
* Create the DOM parser's member value before placing it (#5985)

json_sax_dom_parser::set_member() constructed the new value in place over
the null member. basic_json(value_t) sets the type before the json_value
allocates, so a std::bad_alloc left a member typed object/array with a
null pointer, and the destructor crashed instead of propagating the
exception. Construct the value first and move it over the member (the
move constructor is noexcept).

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

* Fix CI for the parse() bad_alloc sweep test (#5985)

- sweep_allocator: provide max_size(), construct() and destroy(), which
  GCC 4.8's std::map calls on the allocator directly.
- Declare the non-throwing test lambdas noexcept (-Werror=noexcept on
  recent GCC).
- Give the sax_parse lambda an explicit return type; Clang 3.4 crashes on
  the deduced one in C++11 mode.
- Skip the parser callback sweep with iterator debugging (MSVC debug
  builds, clang-cl), where containers allocate debug proxies inside
  noexcept move constructors and terminate instead of throwing, as in the
  other allocator tests.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasAgbDGG28MqXjQvLqp
Signed-off-by: Claude <noreply@anthropic.com>

* Construct a scalar member in place; only a throwing value goes through a temporary

Creating the value first and moving it over the member is needed only when
creating it can throw (a string, a binary value or a container). A scalar
or null is again constructed in place, without the extra move and destroy
per member (and, with JSON_DIAGNOSTICS, without the extra set_parents()).

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

* Spell the nothrow trait without && and fix the construct_member comments

The dispatch in set_member tests std::is_nothrow_constructible, not
whether the value is a scalar. Say so in the comments, and drop the &&
from the trait argument (equivalent for a forwarding reference) so that
astyle no longer inserts spaces around the template brackets.

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

* Say "for example" in the construct_member comments

The overloads are selected by std::is_nothrow_constructible, not by the
kind of value: a custom type that cannot throw takes the first one.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Signed-off-by: Claude <noreply@anthropic.com>
Co-authored-by: Claude <noreply@anthropic.com>
 2026-11-02 18:25:30 +01:00
Niels Lohmann 100f676b3e Restore the two commits of #6005 that the stack merge dropped (fixes the build of develop) (#6012) 
* basic_json, iterators, serializer: remove checks that invariants make dead

Branch coverage of the test suite and of 24k mutated inputs showed
these conditions as never taken; each is implied by the code around it:

- copy_object_level(): `src_it != src_object.cend()`; dst was built from
  exactly src_object.size() unique keys and src_it advances at most once
  per member
- the general comparison operators (equal_general, less_general,
  three_way_general): the five same-type scalar cases, which the inline
  fast path of every operator handles before calling them (now an
  assert); and the NaN half of compares_unordered() in the mixed-type
  branch, reached only after all six number pairs returned, where only
  a discarded operand is unordered
- serializer, ensure_ascii: the reset of `bytes` under error_handler_t::keep
  and the surrogate-pair escape in the UTF8_ACCEPT case; every
  well-formed multi-byte character is escaped by write_u_escapes() before
  decode() sees it, so decode() only ever accepts DEL here, a single byte
  of which nothing was buffered (now asserts)
- iter_impl(pointer): the if/else chain assigned value-initialized
  iterators to the value-initialized m_it

No change in behaviour: a build that aborts on each removed side passes
the test suite, the fuzz corpora and 23.2M dumps of all 1-, 2- and
boundary 4-byte strings in both ensure_ascii modes.

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

* iter_impl: keep the type-dependent initialization in the constructor

The check is not needed for correctness (m_it is value-initialized), but
without it GCC 13 generates slower iteration loops: a recursive walk over
a parsed document takes 0.5-2.7 % longer (callgrind: +1.9 % instructions
on twitter.json, +0.95 % on canada.json). Clang generates identical code
either way. See the measurements in #6005.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-02 18:23:44 +01:00
dependabot[bot] bd067fd08c Bump mkdocs-git-revision-date-localized-plugin in /docs/mkdocs (#6011) 
Bumps [mkdocs-git-revision-date-localized-plugin](https://github.com/timvink/mkdocs-git-revision-date-localized-plugin) from 1.6.0 to 1.6.2.
- [Release notes](https://github.com/timvink/mkdocs-git-revision-date-localized-plugin/releases)
- [Commits](https://github.com/timvink/mkdocs-git-revision-date-localized-plugin/compare/v1.6.0...v1.6.2)

---
updated-dependencies:
- dependency-name: mkdocs-git-revision-date-localized-plugin
  dependency-version: 1.6.2
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
 2026-11-02 17:57:02 +01:00
Niels Lohmann 3354436ec4 json_view: remove checks that invariants make dead (#6006) 
Branch coverage of the test suite and of 24k mutated inputs showed
these conditions as never taken; each is implied by the code around it:

- view_serializer::write_codepoint<EnsureAscii>(): the only caller
  passes the byte a run of plain output stopped at (a quote, a
  backslash or a control character), so the function is now
  write_escaped(), which writes that byte's escape sequence
- load_image(): `owned_image.empty() || image != owned_image.data()`;
  both callers hand in a fresh document_data, and for load(vector&&)
  the image is owned_image itself
- set_moved(): reserve_moved(); all three callers reserved first or
  have the moved flag set (the documented precondition)
- view_side::string() and json_side::string() in equal(): only used
  after both sides were found to be strings, so they read the string
  directly (and are noexcept)
- number<false>(): the '1'..'9' test after a sign-less dispatch, which
  only happens for a digit
- value_range(): the pre-loop `is_new || off >= size` test, which the
  loop's first pass repeats on the same node

No change in behaviour: a build that aborts on each removed side passes
the test suite and the fuzz corpora.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-02 17:54:40 +01:00
Niels Lohmann 596028c460 Drop the null_result parameter JSON_IMPLEMENT_OPERATOR no longer uses (#6005) 
Without the same-type scalar cases, the macro body has no use for it, and
JSON_IMPLEMENT_SCALAR_CASES is now used only by JSON_IMPLEMENT_SCALAR_FAST.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-02 17:54:39 +01:00
Niels Lohmann 5c4f585ac2 Lexer, parser, stream adapter, SAX: remove checks that invariants make dead (#6004) 
Branch coverage of the test suite and of 24k mutated inputs showed
these conditions as never taken; each is implied by the code around it:

- lexer: `next_unget` in get_codepoint_bulk() and scan_literal_bulk().
  unget() is only called at the end of scan_number(), in scan_comment()
  and in skip_bom(); every token scan starts with a plain get() in
  skip_whitespace() that consumes a pending unget, and nothing between
  that get() and the bulk helpers ungets (now asserts, as in
  get_after_string_run())
- lexer: `number_type == value_integer` in convert_integer(): both
  callers exclude value_float and the type has three values
- parser: `!context.empty()` in exception_message(): all callers pass a
  literal
- input_stream_adapter: `refill` in get_character_slow(): the function
  is only called after get_character() found the get area exhausted,
  and the variable recomputed that comparison
- json_sax_dom_callback_parser: `ref_stack.back()` in key() (the null
  case returned a few lines earlier, and the callback in between cannot
  reach ref_stack), `is_structured()` in end_object() (non-null entries
  are only pushed for objects and arrays), `!key_stack.empty()` in
  current_key() (a kept object pushed its key before any value)

No change in behaviour: a build that aborts on each removed side passes
the test suite, the fuzz corpora and 40k random documents through every
input adapter in four macro configurations.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-02 17:54:39 +01:00
Niels LohmannandClaude Opus 5.5 1d69ef9ab4 Raise line coverage to 99.9 %: fix the measurement, remove unreachable code, add tests (#5997) 
* CI: measure line coverage without lcov's unexecuted-block adjustment

Drop geninfo_unexecuted_blocks=1 from the lcov capture of ci_test_coverage:
it reset every line of an inlined or templated function to 0 as soon as one
copy had an unexecuted block, which understated the line coverage by about
three points.

Add -fvar-tracking-assignments to both coverage builds. At -O0, GCC inlines
always_inline functions before it places the coverage counters, so the call
sites of such helpers (put_literal() and others) got no line record and
showed as 0 in an -O3 translation unit that never reaches them. With the
flag, the call sites carry counts in every translation unit. The generated
code is identical.

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

* Remove unreachable code found by the coverage analysis

Remove code that no input can reach, and mark the lines that cannot be
covered with LCOV_EXCL_LINE:

- BJData writer: the dry_run parameter of the ND-array element writers was
  always true; replace them by range checks.
- BON8 writer: call throw_integer_out_of_range() directly instead of
  write_bon8_value() for values that always throw.
- binary_writer: integer_bits() is only called for integers of up to 64 bits.
- serializer, view serializer, lexer: replace guards that the callers make
  unreachable by assertions or by the simpler code (surrogate pairs under
  ensure_ascii, next_unget, '-' at the end of the buffer).
- json_view: drop unreachable branches in scalar(), set(), check_utf8_scan(),
  append_input_impl() and unescape().
- Mark exception-cleanup braces, 2 GiB limits, big-endian and 32-bit code, and
  fall-through case labels with LCOV_EXCL_LINE.

No behavior changes for any input that reaches these functions.

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

* Tests: cover the remaining lines of the library headers

Add tests for the lines of include/nlohmann that were not covered: the
binary readers and writers, the lexer and locale paths, the json_view
modules, the custom number, key and array types, json_pointer, json_patch,
diff and the iterators.

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

* Fix test failures in the coverage tests

- unit-custom-object-key-type: remove the unused make_strict_key(strict_key)
  overload, the unused range constructor and default constructor, and guard
  data() with JSON_DIAGNOSTICS (unused-function/-member-function errors with
  GCC and clang -Weverything).
- unit-json_view_compare: move the two new sections to the new
  unit-json_view_compare_values.cpp, as the object file got too large for the
  MinGW assembler again, and use a std::map with std::greater instead of
  std::unordered_map, which does not accept the incomplete basic_json
  (clang 3.9, icpc).
- unit-json_view_dump: rename the variables that hid outer ones (MSVC C4456).
- unit-stream-bulk-scan: restore the real size of the oversized get area
  before the adapter is destroyed (JSON_PRECISE_STREAM_POSITION reads the
  character at the read position), and skip the test where the streambuf
  cannot hold a get area larger than an int (MSVC).
- unit-regression1: with JSON_NO_THREAD_LOCAL, copies are built member by
  member and keep correct timestamps, so check the corresponding outcome.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasAgbDGG28MqXjQvLqp
Signed-off-by: Claude <noreply@anthropic.com>

* Return std::size_t from the hash helper in the ordered_json test

MSVC (Win32) rejected the implicit conversion of the unsigned long long
product to the 32-bit std::size_t (C4244 as an error). Also note when
JSON_NO_THREAD_LOCAL is set in the regression test.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasAgbDGG28MqXjQvLqp
Signed-off-by: Claude <noreply@anthropic.com>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Signed-off-by: Claude <noreply@anthropic.com>
Co-authored-by: Claude <noreply@anthropic.com>
 2026-11-02 17:54:38 +01:00
Niels Lohmann ff0bdfdef3 Keep the byte range in exceptions about the root value (#5990) 
* Keep the byte range in exceptions about the root value (#5987)

With JSON_DIAGNOSTICS and JSON_DIAGNOSTIC_POSITIONS both set, exception::diagnostics()
and the json_view diagnostics() returned early for a value without a path (the
root), dropping "(bytes a-b)". Build the "(path) " prefix only when there are
tokens and always append the byte range.

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

* Guard the null value of a value-initialized iterator; drop the unneeded found flag

With the root's byte range, diagnostics() reaches get_byte_positions() also
with JSON_DIAGNOSTICS when there is no value, as for a value-initialized
iterator (invalid_iterator.212). get_byte_positions() now returns no range
for a null value, the same change as #6003, so either can be merged first.

In the view, a value that value_path() does not find leaves no tokens, so the
found flag added nothing to the tokens.empty() test.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-02 17:50:40 +01:00
dependabot[bot] 7328310136 Bump mkdocs-material from 9.7.7 to 9.8.0 in /docs/mkdocs (#6010) 
Bumps [mkdocs-material](https://github.com/squidfunk/mkdocs-material) from 9.7.7 to 9.8.0.
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](https://github.com/squidfunk/mkdocs-material/compare/9.7.7...9.8.0)

---
updated-dependencies:
- dependency-name: mkdocs-material
  dependency-version: 9.8.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
 2026-11-02 17:48:55 +01:00
Niels LohmannandClaude Opus 5.5 bfe69c73c2 json_view: get<T>() of a boolean throws for the exact number types, as basic_json does (#5992) 
* json_view: get<T>() of a boolean throws for number_integer_t, number_unsigned_t and number_float_t like basic_json (#5988)

basic_json::get<T>() of a boolean throws type_error.302 for exactly
number_integer_t, number_unsigned_t and number_float_t (dedicated from_json()
overloads) and gives 0/1 for every other arithmetic type. The view returned
0/1 for all of them, contradicting its documentation. The view now throws
the same exception (same message, with path/bytes decoration) for these three
types. basic_json is unchanged; its behavior is documented and pinned by a test.

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

* tests: skip throwing json_view bool get<T>() combinations without exceptions (#5988)

check_boolean_get_parity() called get<T>() for number_integer_t,
number_unsigned_t and number_float_t in its JSON_NOEXCEPTION branch, but a
boolean throws type_error.302 for exactly these types, so JSON_THROW aborted
test-json_view_cpp11/cpp17 in ci_test_noexceptions. Skip these combinations
there; the throwing checks stay in the exceptions-enabled build.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasAgbDGG28MqXjQvLqp
Signed-off-by: Claude <noreply@anthropic.com>

* Expect the byte range of the root in the json_view boolean get<T>() test

With JSON_DIAGNOSTIC_POSITIONS, the type_error.302 message starts with
"(bytes 0-4)"; build the expected text with json_view_test::message(),
as the other tests of the root value do.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasAgbDGG28MqXjQvLqp
Signed-off-by: Claude <noreply@anthropic.com>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Signed-off-by: Claude <noreply@anthropic.com>
Co-authored-by: Claude <noreply@anthropic.com>
 2026-11-02 17:48:43 +01:00
Niels LohmannandClaude 494a74c242 insert(): strong guarantee for single elements, basic guarantee for the rest (#5996) 
* Make basic_json::insert() provide its documented strong exception guarantee (#5986)

A failed allocation while the new elements were copied left the value
changed, and with JSON_DIAGNOSTICS stale parent pointers behind. The
extra work now happens almost only on the failure path:

- Array insert(pos, cnt, val) and insert(pos, first, last) append the
  copies at the end and rotate them into place. If a copy throws, the
  appended elements are erased again (noexcept) and the parents are set.
  Moving a basic_json cannot throw, so reallocation is safe. This is no
  slower than vector::insert (faster for numbers), needs no temporary
  array, and keeps the elements that libstdc++ lost on reallocation.
- Array insert(pos, val) copies a non-scalar value first and inserts it
  by move, except at the end, where vector::insert is strong. Scalars
  keep the direct path.
- The object range insert(first, last) into an empty object uses the
  container's own range insertion and clears the object on an exception.
  Into a non-empty object it inserts member by member and logs one bit
  per source member (a new member is detected by the size change; no
  allocation for the first 256 members); on an exception the members
  added are erased by walking the source range. No assumption that
  key_type is string_t.
- The parents are set when a failed insertion is undone.

The regression test fails every allocation of every insert() overload in
turn, for json and ordered_json, and checks the value and its parents.

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

* Fix clang-tidy and -Wnrvo findings in insert rollback helpers

Declare the rollback helpers non-movable, replace the nested conditional
and C array in object_insert_rollback, silence the intentional copy in the
allocator test, and avoid the missed NRVO in the test factory lambda.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasAgbDGG28MqXjQvLqp
Signed-off-by: Claude <noreply@anthropic.com>

* insert(): strong guarantee for single elements, basic for the rest

Rework of the previous two commits, following the discussion in #5996:
the standard containers give the strong guarantee only for a single
element (std::vector: at the end, or if the exception does not come from
copying T; std::map: single-element insert), and copying a basic_json
allocates. Rebuilding a rollback for the count, range and object-range
overloads on top of array_t/object_t made the code verbose and slower.

- insert(pos, const basic_json&): at end() forward as before (the
  standard covers it); elsewhere copy first and insert by move, as
  libstdc++ does internally (libc++ shifts the tail before copying).
- insert_iterator() and object insert(first, last) set the parents in a
  scope guard, so a failed insertion leaves a valid value with
  JSON_DIAGNOSTICS too (the next assert_invariant() aborted before).
- Docs: strong guarantee for (1), basic guarantee for (2)-(5); the
  argument checks throw before anything is changed.
- Test: allocation-failure sweep checks the strong guarantee for (1) and
  validity, type and parents for the other overloads.

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

* insert(): document the exception safety of overloads 2 to 5 once

The four basic-guarantee statements were identical up to array/object.

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

* insert(): simplify the wording of the basic guarantee

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Signed-off-by: Claude <noreply@anthropic.com>
Co-authored-by: Claude <noreply@anthropic.com>
 2026-11-02 17:48:29 +01:00
Niels LohmannandClaude Opus 5.5 bdc737db6d json_view: dump() without StringType::capacity() (#5999) 
* json_view: dump() without StringType::capacity() (#5994)

output_buffer::grow() compared the output size with m_out.capacity(),
which the StringType requirements do not include, so dump() did not
compile with the tests' alt_string. Keep what was last reserved in the
buffer itself and use it as a lower bound of the capacity instead.

Add json_view tests with alt_string (read-only and editable documents,
dump with several growth steps, save/load), and document reserve(n) and
resize(n) as the StringType requirements of basic_json_view::dump.

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

* Use a raw string literal in the alt-string json_view test

clang-tidy (modernize-raw-string-literal) rejects the escaped literal.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasAgbDGG28MqXjQvLqp
Signed-off-by: Claude <noreply@anthropic.com>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Signed-off-by: Claude <noreply@anthropic.com>
Co-authored-by: Claude <noreply@anthropic.com>
 2026-11-02 17:48:16 +01:00
Niels LohmannandClaude 66e2eeeec0 Do not construct the base class when destroying a container (#6000) 
* Do not construct the base class when destroying a container (#5995)

json_value::destroy_container() and destroy_walk() used default-
constructed basic_json values as stand-ins, which construct a
CustomBaseClass that belongs to no value. A base class whose default
constructor allocates made the noexcept destructor allocate again, and
terminate if that allocation failed, which #5762 set out to prevent.

Use data (type and value, no base class) as the stand-in instead, and
pass the children's m_data to the walk helpers.

Add a test with a counting base class: destroying a value constructs no
base object and destroys exactly one per value, also for values nested
deeper than the recursion depth limit.

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

* Release the test value with = nullptr instead of reset()

clang-tidy (readability-ambiguous-smartptr-reset-call) rejects j.reset()
because the pointee inherits a reset() from counting_base.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasAgbDGG28MqXjQvLqp
Signed-off-by: Claude <noreply@anthropic.com>

* Use std::swap for the container stand-in in destroy_container

The unqualified call after `using std::swap` would let a user-provided
swap(json_value&, json_value&) intercept the destruction path. Call
std::swap directly.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Signed-off-by: Claude <noreply@anthropic.com>
Co-authored-by: Claude <noreply@anthropic.com>
 2026-11-02 17:48:03 +01:00
Niels LohmannandClaude Opus 5.5 03d408aafa JSON_DIAGNOSTIC_POSITIONS: comparing a value-initialized iterator throws instead of crashing (#6003) 
* JSON_DIAGNOSTIC_POSITIONS: comparing a value-initialized iterator throws instead of crashing

With JSON_DIAGNOSTIC_POSITIONS, comparing a value-initialized iterator
(which has no container) with another iterator built the
invalid_iterator.212 message from the byte positions of the iterator's
value, which is a null pointer: UBSan reports "member call on null
pointer" in exception::get_byte_positions(), then the process crashes.
Every other configuration throws invalid_iterator.212.

get_byte_positions() now returns no positions for a null value, as the
JSON_DIAGNOSTICS path already does.

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

* Declare the value-initialized iterator in the test const

clang-tidy (misc-const-correctness) flags it, as it is only compared.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasAgbDGG28MqXjQvLqp
Signed-off-by: Claude <noreply@anthropic.com>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Signed-off-by: Claude <noreply@anthropic.com>
Co-authored-by: Claude <noreply@anthropic.com>
 2026-11-02 17:47:48 +01:00
Niels LohmannandClaude Opus 5.5 76dbe8f9c9 Fix the red CI on develop: Visual Studio 2017 build of the BSON writer, Valgrind timeouts (#6009) 
* CI: give the Valgrind tests a timeout of one hour

Under Valgrind, test-json_view_builder_cpp11 and test-ordered_json_cpp11
took 1435 s and 1390 s on develop (ddc34f5), close to ctest's default
timeout of 1500 s. On the next run (b2674a4) the whole job was about 10 %
slower and both timed out, failing ci_test_valgrind on develop and on
every PR based on it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasAgbDGG28MqXjQvLqp
Signed-off-by: Claude <noreply@anthropic.com>

* BSON writer: drop the SFINAE guard that Visual Studio 2017 cannot deduce

write_bson_document_single_pass() was a member template enabled by
is_detected<sink_written_t, SinkType>. MSVC 19.16 (Visual Studio 2017)
fails to deduce it through the class-scope alias template (C2672, C2783)
when it compiles to_bson() and to_bon8(), so every Visual Studio 2017
job on AppVeyor fails since #5979.

The guard is not needed: as a non-template member of the class template,
the function is only instantiated when called, and its only caller is
the write_bson_document() overload for sinks that have written(), which
already calls oa.written() and oa.rewind() itself.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasAgbDGG28MqXjQvLqp
Signed-off-by: Claude <noreply@anthropic.com>

---------

Signed-off-by: Claude <noreply@anthropic.com>
Co-authored-by: Claude <noreply@anthropic.com>
 2026-11-02 17:47:21 +01:00
Niels Lohmann b2674a4a2f BSON reader: check array element names in place in strict mode (#5984) 2026-11-01 21:03:35 +01:00
Niels Lohmann e2423a1857 CI: pin ubuntu-latest jobs to ubuntu-26.04 (#5983) 
GitHub is moving the ubuntu-latest label from Ubuntu 24.04 to 26.04
between October 19 and November 19, 2026 (actions/runner-images#14748).
Pin every ubuntu-latest job to ubuntu-26.04 so the switch does not
change the toolchain under our jobs, and so the behaviour does not
depend on when GitHub reaches our runs.

Jobs pinned to ubuntu-24.04 and ubuntu-24.04-arm are unchanged.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-01 20:43:07 +01:00
Niels Lohmann 67b103e506 Fix clang-tidy errors in json_view tests on develop (#5989) 
readability-math-missing-parentheses in unit-json_view_builder.cpp (#5974)
and performance-inefficient-string-concatenation in
unit-json_view_positions.cpp.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-01 20:42:58 +01:00
Niels Lohmann ddc34f546a json_view: exceptions name the path and the bytes of the value (#5974) 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-01 17:25:26 +01:00
Niels Lohmann f022e3c59c Binary readers and writers: faster UTF-8 checks of strings (#5982) 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-01 17:23:27 +01:00
Niels Lohmann 9742edc294 BSON writer: write to_bson(j) in one pass, with sizes written afterwards (#5979) 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-01 17:23:12 +01:00
Niels Lohmann 517444b504 accept() checks strings without copying them (#5978) 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-01 17:22:58 +01:00
Niels Lohmann fb515ddc34 UBJSON/BJData readers: read optimized arrays of numbers in one loop (#5981) 
* UBJSON/BJData readers: read optimized arrays of numbers in one loop

An array with a type marker for a fixed-size number ($U, $i, $I, $l, $L,
$d, $D, and BJData's $u, $m, $M), including the data of a BJData ndarray,
gives its elements no markers. When the input is contiguous, read the
elements that are in the input in one loop - load, byte swap for the
format's byte order, emit - instead of one trip through
parse_ubjson_internal and get_ubjson_value per element. Elements the
input ends before, other types, and non-contiguous inputs are read as
before.

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

* UBJSON/BJData tests: assign the parsed value instead of casting it to void

GCC reports -Werror=unused-result for static_cast<void>(json::from_ubjson(...))
and json::from_bjdata(...): a cast to void does not silence warn_unused_result
on GCC. Assign to a json, as the other tests do.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-01 17:22:33 +01:00
Niels Lohmann edf8d17601 MessagePack reader: read runs of scalar array elements in one loop (#5980) 
* MessagePack reader: read runs of scalar array elements in one loop

As for CBOR: when an array opens and the input is contiguous, read the
integers, floats, booleans, and nils that follow in a tight loop instead
of going through parse_msgpack_internal and parse_msgpack_value for every
element. The loop stops at any other kind of value and when fewer than 9
bytes are left; those values are read by the general path as before.
Non-contiguous inputs are not affected.

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

* MessagePack reader: enter the scalar run only when a scalar follows

As for CBOR: enter_msgpack_array tests the first byte and the remaining length
inline and calls the out-of-line run only for a scalar, so arrays of maps or
strings no longer pay for a call that reads nothing; the run's loop condition
moves to the end (do-while).

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

* MessagePack reader: mark the initial accepted in the scalar run as a false-positive dead store

ci_infer reports DEAD_STORE for 'bool accepted = true;' in the MessagePack
scalar run, as in the CBOR one, because every case assigns accepted before it
is read.

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

* MessagePack tests: assign the parsed value instead of casting it to void

GCC (ci_test_gcc) reports -Werror=unused-result for
static_cast<void>(json::from_msgpack(...)): a cast to void does not silence
warn_unused_result on GCC. Assign to a json, as the other tests in the file do.

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

* MessagePack reader: drop the scalar pre-check before the run

enter_msgpack_array now calls the run directly, and parse_msgpack_scalar_run
tests the remaining count and length at the top of a while loop instead of
relying on msgpack_scalar_follows(); its own switch already leaves on any
value that is not a scalar.

Instructions per repetition, new/old: SAX canada 0.946 (clang) and 0.973
(GCC 13), DOM read canada 0.991 / 0.992; no row more than 0.3 % higher.

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

* MessagePack reader: say why the initial accepted in the scalar run stays

As for CBOR: Infer's DEAD_STORE report is right, not a false positive. The
initializer is kept for clang-tidy's cppcoreguidelines-init-variables.

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

* MessagePack reader: give the scalar run the bulk tag instead of a wrapper

As for CBOR: parse_msgpack_scalar_run takes the bulk-scan tag itself and is
the function kept out of line, so parse_msgpack_array_start goes.

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

* MessagePack reader: start the scalar run's accepted at false

As for CBOR: Infer ignores dead stores of 0, so the suppression goes.

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

* MessagePack reader: let the scalar run find its array itself

As for CBOR: parse_msgpack_scalar_run reads container_stack.back() in its
bulk version, so the caller no longer evaluates it for input that is not
contiguous.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-01 17:22:32 +01:00
Niels Lohmann aecbef3949 Binary readers: swap the bytes of floats with a single byteswap (#5976) 
* Binary readers: swap the bytes of floats with a single byteswap

byte_swap reversed float and double values byte by byte. GCC does not
merge that loop into one bswap, and C++23's std::byteswap accepts only
integers. Overloads for float and double now copy the bits into a
uint32_t/uint64_t, call detail::byteswap, and copy them back. This
applies to every binary reader that uses get_number.

In the CBOR reader, the single- and double-precision float cases call a
non-inlined helper. Without it, GCC stopped inlining the stream
adapter's get_character() into parse_cbor_internal, which made reading
from a std::istream about 0.5 % slower.

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

* CBOR reader: inline get_cbor_float() and always inline get() instead

The never-inlined get_cbor_float() costs a call for every float read
from input without bulk access: reading canada.json from CBOR through a
FILE* became 5.6 % slower on Apple clang in the benchmark suite. The
helper existed only because GCC 13 stopped inlining the stream adapter's
get_character() into parse_cbor_internal. Always inlining
binary_reader::get() fixes that as well.

callgrind, all binary formats on buffer, std::istringstream and FILE*
input (canada and citm_catalog): GCC 13 0.986-1.003, GCC 16 0.994-1.006,
Clang 23 identical. Apple clang suite: FromBinaryFile/cbor/canada 0.939,
geomean of the 53 binary reader rows 0.998.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-01 17:22:32 +01:00
Niels Lohmann 6c3ab966d3 CBOR reader: read runs of scalar array elements in one loop (#5975) 
* CBOR reader: read runs of scalar array elements in one loop

When a definite-length CBOR array opens and the input is contiguous, read
the integers, floats, booleans, and nulls that follow in a tight loop
instead of going through parse_cbor_internal's container logic and
parse_cbor_value's dispatch for every element. The loop stops at any other
kind of value and when fewer than 9 bytes are left; those values are read
by the general path exactly as before. Non-contiguous inputs are not
affected (tag dispatch on the bulk-scan capability).

Also pass a member empty string as the number source to number_float
instead of constructing a std::string for every float.

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

* CBOR reader: address review of the scalar-run reader

- parse_cbor_scalar_run: set the size explicitly in every case that
  reads a value, instead of relying on a default that every other case
  overwrites.
- Remove cbor_scalar_follows(): parse_cbor_scalar_run already returns on
  the same conditions, and without the pre-check SAX canada needs another
  8.5 % fewer instructions with GCC 13 (0.915 against the previous
  version), with no row more than 0.5 % worse (Mac and GCC).
- Restore the comment on why parse_cbor_internal copies the container
  frame.

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

* CBOR reader: enter the scalar run only when a scalar follows

An array of containers or strings called the out-of-line run start once per
array only to leave it at once; on nested data (arrays of objects) that call
made reading slower than before the run reader. enter_cbor_array now tests the
first byte and the remaining length inline and calls the run only for a
scalar, so the run's loop condition moves to the end (do-while).

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

* CBOR reader: mark the initial accepted in the scalar run as a false-positive dead store

ci_infer reports DEAD_STORE for 'bool accepted = true;' in
parse_cbor_scalar_run because every case assigns accepted before it is read.

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

* CBOR reader: drop the scalar pre-check before the run

enter_cbor_array calls the run directly again, and parse_cbor_scalar_run
tests the remaining count and length at the top of a while loop; its own
switch already leaves on any value that is not a scalar. The MessagePack
reader is built the same way.

Instructions per repetition, new/old: clang SAX canada 0.983, read canada
0.993; GCC 13 read canada 0.997, the other rows at most 1.004.

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

* CBOR reader: say why the initial accepted in the scalar run stays

Infer's DEAD_STORE report is right, not a false positive: every case that
reaches the read assigns accepted. The initializer is kept for clang-tidy's
cppcoreguidelines-init-variables.

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

* CBOR reader: give the scalar run the bulk tag instead of a wrapper

parse_cbor_scalar_run takes the bulk-scan tag itself and is the function that
is kept out of line, so the one-line parse_cbor_array_start wrapper goes, as
the UBJSON typed run already does.

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

* CBOR reader: start the scalar run's accepted at false

Infer ignores dead stores of 0 (--liveness-ignored-constant defaults to "0"),
and false is 0 to it, so the suppression and its comment go.

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

* CBOR reader: let the scalar run find its array itself

parse_cbor_scalar_run reads container_stack.back() in its bulk version, so
the caller no longer evaluates it for input that is not contiguous.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-01 17:22:31 +01:00
Niels Lohmann 5337d841d4 Document and test the lifetime of string_view members decoded from a json_view (#5973) 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-01 17:21:31 +01:00
Niels Lohmann 162eda2574 json_view: skip the digits of a fraction 16 bytes at a time (SSE2) (#5971) 
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
 2026-11-01 17:21:19 +01:00