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Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 Niels Lohmann
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1e101ecac1 |
Add BON8 support (#2998)
* Add BON8 support Add to_bon8/from_bon8 and input_format_t::bon8 for BON8, a binary format that uses the byte values that cannot begin a UTF-8 character as type markers, so strings need no length prefix. It is the most compact of the supported binary formats on the benchmark files. The reader is non-recursive like the other binary readers. A string ends at the first byte that cannot continue it, so the reader hands the one or two bytes it reads past a string back to the value that follows. The writer produces the canonical representation of the specification, except for NFC normalization; its output is identical to that of the reference implementation (HikoGUI) on all files of the test data. The round-trip tests need the .bon8 files of json_test_data 3.2.0. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Address review comments - Reuse detail::validate_one_utf8 to check strings in to_bon8; the error now names the first byte of the invalid sequence. - Document that to_bon8 leaves bytes in the output adapter on an exception, and that string_open is only an output of write_bon8_marker. - Explain why the pushback buffer of the BON8 reader cannot overflow. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Select the BON8 float prefix by type get_bon8_float_prefix only depends on the type of its argument, so make the type a template parameter instead of passing an unused value. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Rename a test variable that Flawfinder mistakes for read() Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix the BON8 CI failures - compare the float in write_bon8_float with number_float_t constants, so GCC does not warn about a float-to-double conversion - mark check_bon8_utf8's context as used when exceptions are disabled - choose the compact float prefix in a helper rather than with nested conditional operators (clang-tidy) - use auto for the cast in the BON8 integer reader (clang-tidy) - write the int32 minimum test values as long long literals (MSVC C4146) Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Amalgamate Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Read BON8 strings in bulk from contiguous input - copy the valid UTF-8 of a string in one step when the input is contiguous (twitter.json is read in 1.68 instead of 2.52 ms, jeopardy.json in 196 instead of 297 ms, close to CBOR and MessagePack) - share the new valid_utf8_prefix() with the writer's UTF-8 check, which now skips ASCII 8 bytes at a time - let the fuzzer check that contiguous and stream input give the same value or error, and test both paths in the unit tests - clarify that a second 0xFF after a string is an empty string Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Link the BON8 functions from the other binary format pages Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Name the bulk scan flag after the input, not BON8 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Read BSON keys in bulk from contiguous input BSON keys (and array indices) are C-style strings, which were read byte by byte. For contiguous input they are now read up to their \x00-byte in one step, using the same bulk_scan flag as BON8 strings: twitter.json is read in 1.46 instead of 2.01 ms, citm_catalog.json in 2.93 instead of 3.33 ms, jeopardy.json in 182 instead of 207 ms. canada.json, whose keys are almost all one-digit array indices, takes 2 % longer. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix the BON8 CI failures of the bulk-read tests - skip the contiguous-versus-stream tests of BON8 strings and BSON keys when exceptions are disabled: they catch the parse errors of invalid input, and without exceptions the library aborts instead - use static_cast for the int64 test value (google-readability-casting) Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Move the explicit basic_json instantiation into its own test file Linking test-regression3_cpp20 with clang and MinGW failed with "relocation truncated to fit: IMAGE_REL_AMD64_REL32 against `.rdata'", as test-regression2 did before #5511. The explicit instantiation of basic_json<> for #4825 compiles every member function, including the BON8 reader and writer, into that object, and it was already close to the limit (2,226,104 bytes on develop, 2,234,960 with BON8; clang -O1, C++20). Give the instantiation a file of its own: unit-regression3 is now 1,594,736 bytes and unit-explicit_instantiation 1,095,064. The new file mentions JSON_HAS_CPP_17 and JSON_HAS_CPP_20 so it keeps being built for the C++17 standard the regression was about. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Convert the bytes of the BON8 test strings explicitly The str() helper constructed a std::string from a byte range, which converts each unsigned char implicitly; -fsanitize=integer reports that for bytes of 0x80 and above (ci_test_clang_sanitizer). Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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Niels Lohmann
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98278dc3f6 |
Fix CI: disable MSVC warning C5285 for the vendored doctest (#5577)
The windows-11-arm runner now ships MSVC 19.51, which reports doctest's
forward declaration of std::tuple as C5285 ("cannot declare a
specialization for 'std::tuple'"). With /WX this breaks the msvc-arm64
job on develop and on every open pull request. Disable the warning for
the test targets, like the other MSVC warnings already disabled there.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
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 Niels LohmannandClaude Sonnet 5
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56b3ee566c |
Fix stack overflow when copying a deeply nested value (#5387) (#5389)
* Bound the descent of the copy constructor basic_json's copy constructor copied objects and arrays by handing the container to its own copy constructor, which copy-constructs every element and so reaches this constructor again, once per nesting level. A value nested deeply enough exhausted the call stack and terminated the process with a segmentation fault - no exception, nothing the caller could catch. Parsing such a value works, as the parser is iterative, and so does destroying one, as #1436 made destruction iterative. Bound how far the copy descends rather than take the call stack away from it. The first levels are copied exactly as they were - the containers copy their own elements, which is by far the fastest way to fill them - and only once the copy has descended 128 levels is the value below it finished without the call stack, through an explicit worklist. Copying can therefore no longer exhaust the stack, however deeply a value is nested, while a value nested less deeply than the bound - all but a vanishing minority - is copied by the very same code as before and pays only for one counter. That counter lives in thread_local storage, as one shared between threads would be raced. JSON_NO_THREAD_LOCAL switches it off for toolchains without thread_local; copying then goes through the worklist right away, which yields the same values but is measurably slower. The deferred values are completed before the copy they belong to returns, so a value copied while another copy is going on - by a custom base class, say - is unaffected by the copy it is nested in. operator= takes its argument by value, so copy assignment is fixed as well. Copying is as fast as it was, within measurement noise (medians of 9 interleaved runs, clang -O3): -1.3% for an array of strings, +0.0% for a flat object, +0.1% for a flat array of numbers, +0.3% for nested arrays, +0.6% for nested objects and +1.2% for a twitter-like document. Copying a three-key object costs about ten nanoseconds more, the counter. Deferring every level instead, rather than only those below the bound, measured between 3% and 9% slower depending on the shape of the value. This fixes #5387 for the copy constructor. dump() is still recursive. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Test the copy constructor's iterative path in CI The copy constructor descends into 128 levels before it finishes a value without the call stack, so the iterative path is otherwise only reached by the few tests that nest deeper than that. JSON_NO_THREAD_LOCAL switches the descent off, which sends every value down that path. Running the whole test suite that way covers it with every object type, string type, allocator, and base class the suite already exercises. The new ci_test_no_thread_local target does that; the macro had no build coverage at all before. Copying a nested value also has to carry over what the element-wise copy constructor would have copied: the parents that JSON_DIAGNOSTICS relies on, and the positions that JSON_DIAGNOSTIC_POSITIONS reports. Both are now checked on either side of the descent bound, for objects and arrays. Neither was tested before, and dropping either one makes the new tests fail. Also quantify what JSON_NO_THREAD_LOCAL costs a copy instead of calling it "measurably slower". Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Split the regression tests so that they keep linking Linking test-regression2 fails with "relocation truncated to fit: IMAGE_REL_AMD64_REL32 against `.rdata'" once its object grows past what the MinGW linker copes with, and the copy constructor's helpers push it over: the object grows by 6.3%, from 4,654,128 to 4,944,920 bytes at -O0, and develop links at the smaller of the two. Building the tests optimized shrinks the object enough to link, but the binaries clang 11.0.1 and clang 18.1.8 then produce crash before doctest prints its first line - 39 of 102 tests on clang 18 - so the objects have to become smaller rather than denser. Moving the test cases that follow "regression tests 2" into a file of their own brings that object to 4,687,888 bytes, which is 0.7% above the size that links today rather than 6.3%. Both files still build for C++11, C++17 and C++20, and run the same 9 test cases and 135 assertions as before, now spread over two binaries. New regression tests belong in unit-regression3.cpp from here on, which is what CONTRIBUTING.md now says. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Do not use thread_local storage with Clang targeting MinGW Every test that copies a value segfaults there - 42 of 105 on clang 11.0.1, 39 of 102 on clang 18.1.8 - while the same tests pass with GCC targeting MinGW, with Clang targeting MSVC, and with every other toolchain the library is tested on. The counter that bounds the copy constructor's descent is the library's first use of thread_local, so that job had never exercised it before. JSON_NO_THREAD_LOCAL already covers toolchains without thread_local storage, and copying yields the same values with it, only more slowly. Define it for this one automatically. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Balance the warning suppression the split separated unit-regression2.cpp opens a DOCTEST_CLANG_SUPPRESS_WARNING_PUSH block at the top and closed it at the very bottom, which the split moved into unit-regression3.cpp: one file was left with a push and no pop, the other with a pop and no push, which clang reports as an error. Give each file the pair it needs. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Check both shapes without a C-style array clang-tidy rejects the array the two shapes were iterated over (cppcoreguidelines-avoid-c-arrays). The array only existed because astyle reformats a range-for over a braced initializer list into something unreadable; naming the two cases avoids both. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Split the regression tests far enough to leave room The first split left unit-regression2.cpp 0.7% below the size develop links at, which the comparison change in the follow-up immediately used up: the MinGW linker fails on test-regression2_cpp20 again, naming copy_shallow and to_partial_ordering among the relocations it cannot fit. Move the sections from "issue #2067" on, and the helper types they use, so that the file stops being the one that decides whether the tests can be linked at all. At -O0 and C++20, unit-regression2.cpp is now 2,964,944 bytes against develop's 4,708,248, and 3,070,568 bytes with the follow-up applied - roughly a third smaller either way, rather than a fraction of a percent larger. The 135 assertions are the same ones as before, now spread over three test cases in two files. Also silence the clang-tidy findings the deep-nesting tests draw: the copies they make are what is being tested, and the reserve() computation gets its parentheses. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Move the #4804 alias to the file that uses it The split left the json_4804 alias behind in unit-regression2.cpp while the test case that uses it went to unit-regression3.cpp, which does not build for C++17 and C++20 as a result. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Include <span> where the split moved its only use The #2546 test case guards itself with __has_include(<span>), but the include itself sat in unit-regression2.cpp's preamble and stayed behind, so the section compiled without a declaration wherever the guard passed - which nvhpc reported and libc++ builds do not, as they skip the section altogether. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Keep the descent bookkeeping in one place Copying carried a depth count, a depth limit and a guard of its own, and the comparison in the follow-up added a second set beside them. Neither operation needs its own: they are never nested inside one another by the library - copying a value does not compare one, and comparing two values does not copy them - and where user code nests them anyway, sharing the count only ends a descent sooner than it had to. So there is now one nesting_depth(), one nesting_depth_limit() and one nesting_depth_guard, which the follow-up uses instead of adding its own. Inverting the test in copy_structured leaves the too-deep case and the no-thread-local case as the same code. The guard takes the count rather than looking it up, because the caller has looked it up already to test it against the limit, and reaching thread-local storage twice on the path that is taken almost every time is worth avoiding. The switch that copies the value of anything that is not an object or an array was written twice - once in the copy constructor, once in copy_shallow - so that adding a value_t meant editing both, and missing one would have been silent. It is copy_leaf_value now, and inlined: both callers have already sorted the containers out, and folding that test into the switch is what keeps a value made mostly of numbers copying as fast as it did. Copying canada.json, citm_catalog.json and twitter.json is within 0.6% of what it was before, measured as a paired ratio over 18 interleaved rounds against a run-to-run spread of 0.3%. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Check that an abandoned copy can still be destroyed Copying a value without the call stack builds the copy from the top down, and every value whose own copy has not been made yet stays a null value until it is. That is what lets a copy be abandoned half-built: the destructor finds nothing but complete values and null ones. Nothing tested it. Failing an allocation part-way through a copy of a deeply nested value does, with the allocator the file already has for exactly this kind of test. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Name the test's locals so Flawfinder stops matching them The code scanning job reports CWE-362 - "check when opening files" - for a test that opens no files: Flawfinder matched a local variable called open. Rename it and its partner. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Keep the descent guard's bookkeeping self-contained nesting_depth_limit() and nesting_depth_guard were only used inside the JSON_NO_THREAD_LOCAL-guarded branch of copy_structured(), but were defined unconditionally. Move them inside the #ifndef, and have the guard look up the depth and test it against the limit itself (via okay()) instead of making the caller do it - the caller no longer needs to touch nesting_depth() at all. Also shrink the thread-local counter to std::uint8_t, matching what its own doc comment already argued. Addresses gregmarr's review comments on #5389. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Make nesting_depth_guard usable regardless of JSON_NO_THREAD_LOCAL nesting_depth_limit() and nesting_depth() stay behind #ifndef JSON_NO_THREAD_LOCAL, since a descent cannot be bounded without a per-thread count. But the guard itself now always exists, becoming a no-op that is never okay() under that macro - the same way the bound is already reached on every call without one. copy_structured() no longer needs to know which case it is in. This is what lets #5390 reuse the guard for comparison, which cannot test JSON_NO_THREAD_LOCAL where the macro-based operators use it: the guard now carries that distinction itself instead of requiring every caller to. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Silence VS2015's C4503 for the custom-base-class test The deep-copy support added for #5387 lengthened the mangled name of std::allocator_traits<...>::construct for the test's map type past VS2015's limit, which /WX turns into a build failure even though the name is only used for (now-truncated) debug info. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Remove dead unused-parameter casts from copy_metadata() @gregmarr asked whether the static_cast<void> pair in the JSON_DIAGNOSTIC_POSITIONS-off branch was needed for an empty json_base_class_t. It isn't: src and dst are already referenced unconditionally by the base-class copy above, so no -Wunused-parameter warning fires either way (checked with -Wall -Wextra -Wunused-parameter, JSON_DIAGNOSTIC_POSITIONS 0 and 1). Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix CI: build custom array types without a fill constructor, re-amalgamate copy_array_level() built the destination array with the fill constructor array_t(count, value), which is not part of the array container interface the library otherwise assumes (e.g. custom ArrayTypes that only provide a default and an iterator-pair constructor, as covered by unit-custom-array-type.cpp). Default- construct the array and resize() it instead, matching how the rest of the codebase already grows array_t. Also re-run the amalgamation, which had fallen out of sync with include/nlohmann/json.hpp. Signed-off-by: Niels Lohmann <mail@nlohmann.me> Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com> |
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Niels Lohmann
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35cdd5f408 |
De-duplicate the diagnostic-positions test files via define-based recompilation (#5474)
tests/src/unit-class_parser_diagnostic_positions.cpp and tests/src/unit-diagnostic-positions-only.cpp were maintained as near-copies of unit-class_parser.cpp and unit-diagnostic-positions.cpp respectively, and had drifted: trailing-comma handling, the #5342 filter-array/filter-value sections, and the cross-input-adapter diagnostics test were never ported to the positions-enabled copy. Fold the position-specific assertions into the base files, guarded by file a second time with the relevant macro set via CMake COMPILE_DEFINITIONS (mirroring the existing test-comparison_legacy pattern) instead of maintaining a separate source file. This removes the duplication and, as a side effect, closes the coverage gaps above since the full test file now compiles under JSON_DIAGNOSTIC_POSITIONS=1 as well. Fixes #5417 Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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Niels LohmannandClaude Opus 4.8
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4a93aa4e2f |
Speed up parsing of contiguous input (numbers, strings, UTF-8) (#5283)
* Speed up number parsing in the lexer (fast paths from the fast_float/simdjson world) The number scanner converted its already-validated digit buffer with std::strtoull/std::strtoll/std::strtod. Those pull in locale and errno machinery and dominate number-heavy parsing (strtod runs at ~6 M/s). Replace them with dedicated parsers over the validated buffer: - parse_integer_unsigned / parse_integer_signed: accumulate digits with overflow detection, falling back to the float path on overflow exactly as the strtoull/strtoll round-trip check did. Overflow behavior is unchanged for narrower or wider custom number types. - parse_float_fast: Clinger's exact fast path for `double` (<=19 significant digits, |exp10| <= 22, significand < 2^53), where significand * 10^exp is exact under IEEE round-to-nearest. This is the same fast path used by fast_float/simdjson. It is bit-identical to strtod on this subset and declines (falling back to strtod) otherwise. Only `double` uses it; float and long double keep std::strtof/std::strtold via a templated overload. Measured on representative data (g++ 13, -O3): - integers: DOM parse +11%, SAX +25-34% - floats: DOM parse +37%, SAX +70% (clang: float DOM ~1.9x) No dependencies added; header-only and C++11-clean. Existing parser, lexer, conversion and deserialization unit tests pass unchanged; a 3M-value random-double fuzz matches strtod bit-for-bit. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Add SWAR bulk string scanning for contiguous input (simdjson-style) scan_string() read the input one character at a time through the input adapter and classified every byte with a large switch. For contiguous byte buffers we can instead scan 8 bytes at a time with a SWAR word test that finds the first byte needing individual handling (the closing quote, an escape, a control character, or a non-ASCII UTF-8 byte) and bulk-append the ordinary run in one go. - input adapters expose supports_bulk_scan / bulk_data / bulk_remaining / bulk_skip for provably-contiguous, same-type, 1-byte iterator ranges (raw pointers in every standard; std::string/std::vector/std::array and friends additionally in C++20 via std::contiguous_iterator). - the lexer gains a bulk_scan capability (gated on lazy_token_string so bypassing the per-character capture cannot lose error diagnostics) and a scan_string_bulk() fast path; streaming/wide/user adapters are unchanged and keep the byte-at-a-time scanner. The run contains no newline (all bytes < 0x20 are treated as special), so position bookkeeping stays exact, and error tokens are still reconstructed lazily from the consumed byte range. The SWAR special-byte test is pure uint64_t arithmetic - no intrinsics, no runtime dispatch, C++11-clean. Measured on representative data, pointer input, g++ 13 -O3 (string values discarded by accept() see the largest gains): long ASCII strings: DOM +4.5x, SAX +14x, accept +17x (to ~2 GB/s) short strings: DOM +15%, SAX +62%, accept +85% escape-heavy: DOM +31%, SAX +26%, accept +28% Same-input parity verified: 200k randomized documents (escapes, multibyte UTF-8, surrogate pairs) accept/parse identically via the contiguous SWAR path and the streaming byte path; unit lexer/parser/diagnostic-position/ deserialization/conversions suites pass unchanged. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Validate UTF-8 in the bulk string scanner (portable ~2-3x on non-ASCII text) The SWAR bulk string path stopped at the first non-ASCII byte and handed every multibyte character to the byte-at-a-time scanner, whose per-byte get()/next_byte_in_range()/add() machinery runs at roughly half the speed of validating straight from the buffer. As a result, dense non-ASCII text (CJK, emoji, accented Latin) parsed ~10-15x slower than ASCII. Fold well-formed UTF-8 into the bulk run: scan_string_bulk() now, on a non-ASCII lead byte, validates one sequence with validate_one_utf8() - which mirrors scan_string()'s per-byte switch ranges exactly (rejecting overlong forms, surrogates, and out-of-range code points) - and appends it in place, continuing until the closing quote, an escape, a control byte, or an ill-formed sequence. All error handling still defers to the byte path, so error messages and positions are byte-for-byte unchanged. Because only well-formed content is fast-pathed and every rejection falls through to the existing scanner, behavior is identical; the win is purely throughput. Measured on pointer input (accept, string values discarded): content g++ 13 clang 18 dense CJK 277 -> 648 ~605 MB/s (~2.3x) dense emoji 299 -> 857 ~702 MB/s (~2.6-2.9x) mixed 90% ASCII 246 -> 331 ~334 MB/s (~1.35x) pure ASCII unchanged (~3.2 / 4.1 GB/s) Verified: 2,000,000 randomized documents built from arbitrary bytes (overlong, surrogate, truncated, out-of-range sequences) accept/reject and parse identically via the contiguous path and the streaming byte path; lexer/parser/diagnostic-position/deserialization/conversions suites pass unchanged. Pure C++11, no intrinsics. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Route contiguous byte containers through the pointer adapter (fast paths in C++11) json::parse(std::string) - the most common entry point - did not benefit from the contiguous fast paths (bulk string scanning, UTF-8 bulk validation, memcpy for binary formats) in C++11..17: std::string::iterator is a library wrapper, not a raw pointer, and pre-C++20 there is no portable way to prove it contiguous, so supports_bulk_scan was false. Only raw pointers, string literals, and C-arrays (and, in C++20, anything modelling std::contiguous_iterator) took the fast path. Detect contiguous single-byte containers (std::string, std::vector<char>, std::vector<std::uint8_t>, std::string_view, ...) via is_contiguous_byte_ container and route them through an iterator_input_adapter built from data()/data()+size(). The generic iterator-based container overload is constrained to exclude these, so the two overloads are disjoint and there is no ambiguity (a plain competing overload loses to the greedy forwarding-reference container overload on reference binding, and a factory partial-specialization is ambiguous - both were tried and rejected). The pointer keeps the container's own element type, so char_type - and therefore all parsing behavior - is byte-for-byte identical to the iterator path (const char* for std::string, const std::uint8_t* for std::vector<std::uint8_t>); only the raw pointer additionally turns on the fast paths. Lifetimes are unchanged: the container outlives the adapter for the full parse expression, exactly as the iterators it replaces did. Measured, C++11, json::parse/accept(std::string), g++ 13: long ASCII strings: accept 201 -> 3200 MB/s (~16x), parse 174 -> 1444 dense CJK: accept 263 -> 697 MB/s (~2.6x) short strings: accept 163 -> 243 MB/s (~1.5x) Verified: char_type preserved for std::string (char) and std::vector<std::uint8_t> (uint8_t); CBOR/MsgPack round-trips from std::vector<std::uint8_t> unchanged; 1,000,000 randomized documents accept and parse identically via std::string and via std::istream; deserialization/user-defined-input/parser/lexer/conversions/diagnostic- position suites pass (20,480 assertions); warning-clean on g++ and clang in C++11/17/20. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Add optional simdutf backend for bulk UTF-8 validation (JSON_USE_SIMDUTF) The bulk string scanner validates UTF-8 straight from a contiguous buffer. The scalar validator caps at ~0.3-0.7 GB/s on non-ASCII text; a SIMD validator reaches several GB/s. Rather than hand-rolling SIMD UTF-8 validation (easy to get subtly wrong - a from-scratch SSE attempt rejected valid CJK), wire in the vetted simdutf library behind an opt-in switch. simdutf is not header-only (it ships simdutf.cpp and uses runtime CPU dispatch), so it is not vendored: defining JSON_USE_SIMDUTF includes <simdutf.h> and routes the bulk validator through simdutf::validate_utf8; the project supplies and links simdutf. Undefined (the default), nothing external is included and the portable C++11 scalar path is used, so the library stays header-only and its baseline behavior is unchanged. Design keeps behavior identical either way: - scan_string_bulk() now finds the run up to the next quote/escape/control byte (non-ASCII allowed) and validates it in one shot; on the rare validation failure it recomputes the exact valid prefix with the scalar helper, so ill-formed input still falls through to the byte path and is reported at the same position with the same message. - the per-sequence scalar path is factored into scalar_string_bulk_run() and is the default backend; the refactor is behavior-preserving and does not change scalar throughput. Verified: default and JSON_USE_SIMDUTF builds accept/reject/parse identically across 2,000,000 arbitrary-byte documents and 1,000,000 mixed-escape/UTF-8 documents (differential fuzz vs the streaming byte path); lexer/parser/diagnostic-position/deserialization suites pass under both configurations (20,188 assertions with the backend enabled); warning-clean on g++ and clang, C++11 and C++20, both configurations. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Add a contiguous fast path for scanning numbers scan_number() reads a number one character at a time through the input adapter (get()) and appends each byte to token_buffer (add()) before converting. For contiguous input, the per-character get()/add() overhead dominates: it is roughly two thirds of the time spent on number-heavy parsing, far more than the value conversion itself. Add scan_number_bulk_contiguous(), which parses the whole number token straight from the input buffer: it validates and classifies the extent with the same grammar as scan_number()'s state machine, materializes token_buffer in one copy (substituting the locale decimal point exactly as scan_number() does), advances the adapter, and reuses the shared convert_number() tail. On anything it does not recognize as a well-formed number it makes no state change and returns token_type::uninitialized, so the caller falls back to scan_number(), which then produces the exact diagnostic. Errors and their positions are therefore unchanged. The conversion tail is factored out of scan_number() into convert_number() so both scanners share it; the fast path is selected by tag dispatch on the existing bulk_scan capability, so streaming/wide/user adapters are unaffected. Measured on pointer input, g++ 13 -O3: - integers: parse +65%, accept +98% - floats: parse +39%, accept +70% Verified: 2,000,000 randomized number documents (including overflow-range integers, long digit strings and %.17g doubles) parse identically via the contiguous path and the streaming byte path, matching value, type and round-trip text; the locale suite and existing parser/lexer/conversions/ deserialization tests pass; a new "lexer number fast path" test checks contiguous-vs-streaming parity, token classification, and that malformed numbers are rejected identically. Pure C++11, no intrinsics. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Move byte-level scan/parse helpers out of lexer.hpp lexer.hpp had grown by ~600 lines of byte-level helpers that have no dependency on the lexer's template parameters and clutter the state machine. Move them, unchanged, into two focused headers as free functions in namespace detail: - number_parse.hpp: parse_integer_unsigned/parse_integer_signed (now templated on the number type) and parse_float_fast (Clinger's exact double fast path, with the decimal point passed as an argument instead of read from a lexer member). - string_scan.hpp: the SWAR string helpers (is_string_special, swar_string_special, find_string_special, validate_one_utf8, scalar_string_bulk_run) and the backend-dispatched string_bulk_run, including the optional simdutf include and find_string_delimiter. lexer.hpp now includes these and calls the free functions; the methods that touch lexer state (scan_string, scan_number, scan_string_bulk, scan_number_bulk_contiguous, convert_number) stay put. This is a pure code move with no behavior change: lexer.hpp drops from 2357 to 1934 lines, the now-unused <cstdint>/<cstring>/<limits> includes are removed, and the free-function form makes the SWAR helpers reusable elsewhere (e.g. the serializer's string escaping). Verified: default and JSON_USE_SIMDUTF builds compile; 2,000,000 number and 2,000,000 arbitrary-byte-string differential-fuzz documents parse identically to before; lexer/parser/conversions/deserialization/locale/ diagnostic-position suites pass (20,576 assertions); warning-clean on g++ and clang in C++11/17/20; the amalgamation regenerates and passes check-amalgamation. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix clang-tidy findings and document JSON_USE_SIMDUTF in the nav - number_parse.hpp: use std::array for the powers-of-ten table (avoid-c-arrays) and `auto` for the cast-initialized result (modernize-use-auto), matching the codebase style (cf. the serializer's utf8d table). Indexing casts keep the -Wsign-conversion build clean. - add JSON_USE_SIMDUTF to the mkdocs navigation so the macro page is reachable. No behavior change; clang-tidy is clean on the new headers and the amalgamation is regenerated. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix number fast path for custom string types without assign() The contiguous number fast path materialized token_buffer with token_buffer.assign(data, len), but string_t is only required to provide the minimal interface the rest of the lexer uses (push_back, append, clear, operator[], ...). Custom string types such as the test's alt_string do not implement assign(), so scan_number_bulk_contiguous() failed to compile for them (unit-alt-string), breaking the gcc/clang standards and old-compiler CI jobs. reset() already clears token_buffer, so fill it with append() - which alt_string and std::string both provide and which the string fast path already relies on - instead of assign(). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Satisfy clang-tidy: parenthesize math and drop unused forwarding reference The CI clang-tidy (newer than the locally available version) reported two additional checks on the new code: - readability-math-missing-parentheses: parenthesize the (a * b) + c digit accumulations in number_parse.hpp. - cppcoreguidelines-missing-std-forward: the contiguous-byte-container input_adapter overload took a forwarding reference but only reads data()/size() and never forwards it. It is already disjoint from the generic container overload via SFINAE, so a plain const& is correct and clearer (and keeps the container alive for the whole parse just as before). No behavior change; char_type and routing are unchanged (std::string and std::vector<std::uint8_t> still take the pointer adapter with char/uint8_t char_type), CBOR/MsgPack round-trips and the 2M number fuzz still pass. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Use std::from_chars (Eisel-Lemire) for float conversion when available The Clinger fast path is exact only for the "easy" subset (<=19 significant digits, |exp10| <= 22); high-precision and scientific floats fall through to strtod, where the failed Clinger attempt actually makes parsing a net loss. std::from_chars implements the Eisel-Lemire algorithm in modern standard libraries: locale-independent, correctly rounded, and fast over the whole value range. convert_number() now tries parse_float_from_chars() first (guarded by __cpp_lib_to_chars, so C++11 and libc++-without-float-support keep the Clinger + strtod path unchanged), then Clinger, then strtof. from_chars is used only when it consumes the entire token; a partial parse means a non-'.' locale decimal point, and an under-/overflow (result_out_of_range) also declines - in both cases the existing strtod fallback supplies the exact value and the well-defined +/-inf/0 the parser expects, side-stepping the P4168 divergence between implementations. float and long double now get the fast path too (Clinger was double-only). Measured, C++17, g++ 13 -O3, json::parse/accept: - canada-style floats: ~unchanged (Clinger already covered them) - high-precision (17 digits): parse 2.1x, accept 2.5x - scientific (17 digits + exp): parse 3.6x, accept 4.1x Verified: C++11 (Clinger/strtod) and C++17 (from_chars) parse every value - including subnormals, boundary values, and 1e9999/1e-9999 over-/underflow - to bit-identical results; 2M number-fuzz clean; conversions/deserialization/ locale/number-fast-path suites pass in both C++11 and C++17; clang-tidy clean; warning-clean on g++ and clang in C++11/17/20. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Guard from_chars use on JSON_HAS_CPP_17, not just __cpp_lib_to_chars libstdc++ 15 defines __cpp_lib_to_chars even in C++14 mode (via bits/version.h pulled in by other headers), but <charconv> is only included under JSON_HAS_CPP_17. That made parse_float_from_chars() reference std::from_chars without the header in C++14 builds, breaking gcc-latest, icpx, and the offline-testdata jobs. Gate the use on JSON_HAS_CPP_17 && __cpp_lib_to_chars so it matches the include condition exactly; C++11/14 always take the scalar fallback. Verified by forcing __cpp_lib_to_chars in a C++14 build: the guard suppresses std::from_chars and it compiles. C++17 behavior is unchanged. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Disable Clinger float fast path under extended FP precision (x87) The contiguous number fast path uses a Clinger-style exact algorithm (significand * 10^scale in double arithmetic), which is only correctly rounded when double operations are evaluated in true 53-bit precision. On the x87 FPU used by 32-bit x86 (FLT_EVAL_METHOD == 2) the single multiply/divide is computed in 80-bit and then double-rounded to double, so a small fraction of values land 1 ULP off. This surfaced as test-cbor_cpp11 and test-msgpack_cpp11 failing on the mingw (x86) job for regression/floats.json: the C++17 builds pass because they take the correctly-rounded std::from_chars path, while C++11 falls back to parse_float_fast(). A 5M-sample check over shortest round-trip decimals reproduces it: 0 divergences with 53-bit doubles, ~1 in 25 000 with 80-bit intermediates; declining to std::strtod fixes all of them. Guard parse_float_fast() on FLT_EVAL_METHOD so it declines whenever the platform evaluates doubles in extended precision, letting the caller use the correctly-rounded std::from_chars / std::strtod path instead. On mainstream x86-64/ARM64 (FLT_EVAL_METHOD == 0) the fast path is unchanged. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Guard <charconv> include with __has_include for GCC 7 GCC 7 sets __cplusplus to the C++17 value under -std=gnu++1z, so JSON_HAS_CPP_17 is defined, but its libstdc++ ships no <charconv> header (added in GCC 8; floating-point from_chars in GCC 11). The unconditional "#if defined(JSON_HAS_CPP_17) #include <charconv>" therefore failed to compile there: "fatal error: charconv: No such file or directory" in the ci_test_compilers_gcc (7) job. Wrap the include in __has_include(<charconv>), mirroring the library's existing handling of <version> and <filesystem> in macro_scope.hpp. When the header is absent, __cpp_lib_to_chars stays undefined and parse_float_from_chars() takes its scalar fallback, so the from_chars use site (already gated on __cpp_lib_to_chars) is never reached. GCC 8-10, which have <charconv> but no floating-point from_chars, are unaffected: they include the header but still take the fallback. GCC 11+ is unchanged. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AXcDtEma2PjxgmPS9cQGzA Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Restore the column when ungetting a newline The contiguous number fast path never reads the character that terminates a number token, while scan_number() reads it and then ungets it. When that character is a newline, get() has already cleared chars_read_current_line, and unget() could only restore lines_read - leaving the column at 0. The two paths therefore reported different columns for the same document: json::parse("[01\n]") -> line 1, column 3 json::parse(stringstream) -> line 1, column 0 Remember the column the newline was read at so unget() can restore it. Both paths now report the position the offending token actually starts at, which also fixes the pre-existing column-0 artifact for streaming input. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Extend the bulk scan fast paths to sized sentinels supports_bulk_scan required IteratorType and SentinelType to be the same type, which excluded std::counted_iterator paired with std::default_sentinel_t - the combination #5268 had already enabled for the memcpy fast path. Such input fell back to the byte-at-a-time scanner even though it is contiguous and its remaining length is computable in O(1). Factor the "distance is computable in O(1)" test into sentinel_is_sized and use it for iterator_is_contiguous, supports_seek, and supports_bulk_scan alike, and share the std::ranges::distance/std::distance dispatch through a remaining_count() helper. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Document JSON_USE_SIMDUTF on the macro overview page The macro was only listed in the API macro index; add it to the supported macros overview alongside the other JSON_USE_* macros, and note that it selects between two definitions of the same inline function and so must be defined identically in every translation unit. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Amalgamate source code Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Cover the counted-iterator bulk scan paths Sized sentinels newly reach the bulk string/number scanners and the seek-based token reconstruction, so exercise both: - diagnostics that quote the offending token, which are rebuilt from the consumed input via copy_consumed_range() - inputs whose count ends before the underlying buffer does, including a closing quote that exists only behind the count, a cut inside an 8-byte SWAR stride, and a cut inside a UTF-8 sequence Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix the SentinelType example on iterator_input_adapter The comment offered "a C++20 sentinel or counted_iterator" as examples of a SentinelType, but std::counted_iterator is the IteratorType - the sentinel it pairs with is std::default_sentinel_t. #5268 corrected the same wording in the API documentation and left the code comment behind. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Do not discard the parse result in the error position check json::parse is declared warn_unused_result, and CHECK_THROWS_WITH_AS evaluates its expression as a discarded statement, so the assertion broke the -Werror builds (GCC -Werror=unused-result, MSVC C4834 under /WX). Compare against the helper that already captures the message instead. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Lock the two number grammars together with a parity test The JSON number grammar is encoded twice: as the scan_number() state machine and as the contiguous fast path. The fast path declining on anything it does not recognize keeps most divergence harmless, but if it ever accepted something the state machine rejects the result would be a silent correctness bug, and the existing test only pinned a hand-written list of numbers. Enumerate every string of length 1..4 over "01.eE+-" (2800 tokens) and require both paths to agree on the parsed value and on the exact error message. Verified to fail if the fast path's grammar is perturbed. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Skip token_buffer for integers on the contiguous path An integer token does not need token_buffer: the number_integer and number_unsigned SAX callbacks take only the value, and the overflow diagnostic rebuilds the text from the input via get_token_string(). Convert straight from the input buffer and materialize the token only for the floating-point tail, which still needs a NUL-terminated buffer for strtod. JSON_DIAGNOSTIC_POSITIONS derives a number's start position from get_string().size(), so the copy is kept when that is enabled. The integer dispatch is factored into convert_integer() and shared with convert_number(), so both scanners keep using one implementation. Integer-heavy input, 400k values, -O3: parse accept gcc 16 +14% +23% clang +15% +22% Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Amalgamate source code Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Cover the bulk string and UTF-8 scanners These paths had no dedicated tests and rested on differential fuzzing only. Add three sections, all comparing the contiguous scanner against the byte-at-a-time one on the parsed value and on the exact error message: - every string of length 1..3 over an alphabet of ordinary ASCII, both specials, a control byte, escape characters, UTF-8 lead and continuation bytes, and a byte that is never valid - each at offset 0 and offset 9, so the bulk scanner sees them with and without a run behind them - every kind of run-ending byte at each offset across two 8-byte SWAR words, so multibyte sequences also straddle the word boundary - the boundaries of every range validate_one_utf8() recognizes: shortest and longest encodings, overlongs, both ends of the surrogate block, U+10FFFF and just past it, and truncated sequences Verified to fail if the bulk validator accepts surrogates, and if the SWAR word test stops detecting control characters. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Format the new string fast path test with astyle The pinned astyle expands a braced-init-list used as a range-for range onto several lines; hoist the two offsets into a named vector instead, which reads better and leaves nothing for astyle to reformat. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix shadowed locals and guard the exception-dependent tests Two problems in the tests added for the bulk scanners, both found by CI: - the inner `const json j` in the counted-iterator diagnostics shadowed the one declared at test-case scope, which -Wshadow rejects on GCC and clang and C4456 rejects on MSVC under /WX; rename them - the new parity checks parse deliberately invalid input, which calls std::abort() rather than throwing when JSON_NOEXCEPTION is defined, so they would have crashed the no-exception build; guard them the way the other tests do json::accept() does not abort, so the UTF-8 range assertions stay compiled without exceptions and keep covering validate_one_utf8() there. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Gate the C++20 iterator classification on JSON_HAS_RANGES Making supports_bulk_scan depend on iterator_is_contiguous meant the trait is now instantiated for every adapter, not only when get_elements() is called. On standard libraries with an incomplete <ranges> that is fatal: libstdc++ 10 evaluates std::contiguous_iterator<std::counted_iterator<T*>> by calling std::to_address, which needs an operator-> its counted_iterator does not have, so satisfaction checking is a hard error rather than false. Reported by clang 14 + libstdc++ 10. JSON_HAS_RANGES already encodes exactly this ("libstdc++ < 11 has incomplete C++20 ranges", #4440), so require it for the C++20 branch. Affected toolchains fall back to the pointer-only test and the byte-at-a-time scanner, which parses identically, just without the bulk fast paths. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Amalgamate source code Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Satisfy clang-tidy in the new bulk scanner tests - give the helper lambdas an explicit std::string return type and return braced initializer lists (modernize-return-braced-init-list) - replace the C-style array of test cases with a std::vector (modernize-avoid-c-arrays) - silence pro-type-member-init on the two brace-initialized aggregates; default member initializers would stop them being aggregates in C++11 Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Avoid escaped literals in the counted-iterator diagnostics list clang-tidy reads "[\"\\ud834\"]" as a literal better written raw, and the two literals written next to each other in "[\"a\x01""b\"]" as a missing comma. The concatenation was there to stop the hex escape swallowing the following character; build those documents from explicit bytes instead and use raw strings elsewhere. The byte sequences are unchanged. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Reattach convert_number's documentation @gregmarr spotted that convert_integer() was inserted between convert_number() and its doc block, leaving convert_integer() with two stacked blocks and convert_number() with none. Comment only; no code change. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Address review comments on the simdutf backend string_bulk_run() had the same `return scalar_string_bulk_run(...)` in both arms of the `#if`. The simdutf arm already falls through when validation fails, so a single return after the `#endif` says the same thing. The JSON_USE_SIMDUTF example showed `#include <simdutf.h>`, which string_scan.hpp already does under the same guard; users only have to put the header on the include path and link the library, not include it themselves. Set the version history entry to 3.13.0, matching the other macro pages documenting unreleased features. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MXDi7NTMKAmoArUZSKMc4T Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Pin the number error position against a non-newline terminator The comment claimed the reported column is the one the offending token starts at. It is the column reached after the token's last character - which is the actual point of the unget() change: a number terminated by a newline now reports what the same number terminated by a space always did. Assert that equality directly, and add a multi-character token where the start and end columns differ, so the invariant cannot be read off a single-character example. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MXDi7NTMKAmoArUZSKMc4T Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Do not repeat the integer conversion that just failed scan_number_bulk_contiguous() converts an integer token straight from the input buffer. When the value does not fit, it materializes token_buffer and calls convert_number(), which tried the very same integer conversion again before falling back to floating point. Recording the outcome in number_type skips the second attempt. The resulting token type and value are unchanged: convert_number() reached the float tail either way. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MXDi7NTMKAmoArUZSKMc4T Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Require a container's value_type to match what data() points at is_contiguous_byte_container accepted any type with a data() returning a pointer to a single-byte integral plus a size(). That is duck typing: the two members say nothing about size() counting the units data() points at. A type where it does not - fixed-size records, say - was routed to the pointer-based adapter and parsed as [data(), data() + size()) bytes, silently truncating input the iterator-based adapter had read in full: struct record_buffer { using value_type = std::array<char, 4>; std::string bytes; const char* data() const; // raw bytes std::size_t size() const; // in records const char* begin() const; const char* end() const; }; json::parse(record_buffer{"[1,2,3,4,5]"}); // parse error at column 3 Requiring the container's own value_type to be that same element type ties the two together. Every contiguous standard container satisfies it, so std::string, std::vector<char>, std::array<char, N> and std::string_view keep the fast path; anything else falls back to the iterator-based adapter, which is always correct. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MXDi7NTMKAmoArUZSKMc4T Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Only compile the simdutf backend from C++17 on simdutf.h rejects anything below C++17 with an #error, so defining JSON_USE_SIMDUTF in a C++11 or C++14 translation unit did not fail with a message about simdutf being unavailable - it failed to compile at all, taking the library's C++11 support with it. Nothing caught this because no build ever compiled that path. Gate the include and both uses on JSON_HAS_CPP_17, the same way number_parse.hpp gates std::from_chars. Below C++17 the macro now has no effect and the scalar validator runs; it accepts and rejects exactly the same input, so the macro is safe to set project-wide even when some translation units use an older standard. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MXDi7NTMKAmoArUZSKMc4T Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Test the simdutf backend in CI JSON_USE_SIMDUTF was documented and shipped but never compiled by anything in the repository, so nothing held the backend to the behavior the docs promise. Add JSON_TestSimdutf (OFF by default), which fetches simdutf and defines JSON_USE_SIMDUTF for every test target, and a ci_test_simdutf target that runs the whole suite in that configuration. Because simdutf needs C++17, the suite is built at C++11 as well, so one job covers both the scalar fallback with the macro defined and simdutf itself. The dependency hangs off test_main, whose usage requirements every test target inherits. The library target and the installed CMake package are deliberately untouched: making nlohmann_json link simdutf would put a find_dependency() in the exported package, which is a separate decision. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MXDi7NTMKAmoArUZSKMc4T Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Warn when JSON_TestSimdutf cannot reach the simdutf backend simdutf needs C++17: without it the dependency does not even compile, and with a C++17 compiler but no C++17-or-later standard under test it builds and then goes unused. Either way the option silently did nothing useful, or broke the configure step outright. Resolve the tested standards first, then check them: when none of them can reach simdutf, skip the dependency and say so, naming which of the two reasons applies and how to fix it. The tests then run against the scalar validator, which is what would have happened anyway. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MXDi7NTMKAmoArUZSKMc4T Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Use record_buffer::data() so clang does not flag it unneeded The record_buffer test type declares data() and size() so the is_contiguous_byte_container trait can see both and still reject the type on its value_type. data() was never called, so clang's -Wunneeded-member-function (under -Weverything -Werror) failed the C++20 build. Assert that data() points at the underlying bytes: it ODR-uses the member and documents the property the type is meant to demonstrate. Co-Authored-By: Claude <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01XAYM1qhSA2FDaDcGfPW3fG Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Skip the float fast path when it cannot succeed parse_float_fast() (Clinger) needs a significand below 2^53, so it always declines once the mantissa has 17 or more significant digits. convert_number() called it unconditionally, so those numbers were walked an extra time before strtod had to run anyway. On streaming input, where scanning is byte-at-a-time and there is no compensating win, that made canada.json about 6% slower than develop. Derive the significant-digit count from token_buffer indices - the digits are not scanned again - and skip the call when it is guaranteed to decline. Both scanners pass the offset where the mantissa ends; the count only has to be corrected for a leading "0", which the JSON grammar admits nowhere else. The integer path returns before the check, so integer-heavy input is unaffected. Values are unchanged: this only avoids an attempt that would have failed. Verified bit-exact against develop over every number in canada.json, floats.json, signed_ints.json, unsigned_ints.json, small_signed_ints.json, citm_catalog.json and twitter.json, for both the contiguous and the streaming scanner. parse, streaming develop before after canada.json 19.4ms 20.5ms 19.3ms floats.json 135.9ms 131.8ms 128.0ms parse, contiguous develop before after canada.json 15.5ms 12.9ms 11.7ms floats.json 98.6ms 69.8ms 66.7ms Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com> |
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c05347dd54 |
Undefine the four JSON_HEDLEY_* macros that leak after including json.hpp (#5475)
* Undefine the four JSON_HEDLEY_* macros that leak after including json.hpp include/nlohmann/detail/macro_unscope.hpp includes hedley_undef.hpp to #undef every JSON_HEDLEY_* macro so none of them leak into the including translation unit. Four macros were missing from that list and therefore stayed defined after #include <nlohmann/json.hpp>: - JSON_HEDLEY_PRAGMA - JSON_HEDLEY_PREDICT_TRUE - JSON_HEDLEY_PREDICT_FALSE - JSON_HEDLEY_CLANG_HAS_DECLSPEC_ATTRIBUTE hedley_undef.hpp is generated (via `make update_hedley`) by grepping hedley.hpp for its own internal `#undef JSON_HEDLEY_X` redefinition guards. JSON_HEDLEY_PRAGMA/PREDICT_TRUE/PREDICT_FALSE have no such guard in upstream Hedley, so they were never picked up. The guard for JSON_HEDLEY_CLANG_HAS_DECLSPEC_ATTRIBUTE also has an upstream typo (`JSON_HEDLEY_CLANG_HAS_DECLSPEC_DECLSPEC_ATTRIBUTE`), so hedley_undef.hpp was undefining the wrong (never-defined) name. Fixes: - include/nlohmann/thirdparty/hedley/hedley_undef.hpp: corrected the DECLSPEC_ATTRIBUTE typo and added the three missing #undef lines, keeping the file's alphabetical ordering. - Makefile (update_hedley target): changed hedley_undef.hpp generation to extract macro names directly from every `#define JSON_HEDLEY_...` in hedley.hpp instead of from existing `#undef` guards, so a future `make update_hedley` run undefines every macro Hedley actually defines, even ones without a pre-existing redefinition guard. This was not run in this PR (it would also pull in an unrelated upstream Hedley sync); hedley_undef.hpp was hand-patched instead and single_include was regenerated with `make amalgamate`. - tests/src/unit-no-macro-leak.cpp: new regression test (picked up automatically by tests/CMakeLists.txt's existing unit-*.cpp glob) that includes json.hpp and then #ifdef/#error-checks every JSON_HEDLEY_* macro name, so any future leak of any of the 151 vendored macros fails the build, not just the four fixed here. Fixes #5408. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Derive the JSON_HEDLEY_* leak-check test from hedley.hpp at build time tests/src/unit-no-macro-leak.cpp previously hardcoded a static list of ~151 #ifdef/#error checks, one per JSON_HEDLEY_* macro name known at the time it was written. That list would silently go stale the next time `make update_hedley` pulls in a vendor update that adds, removes, or renames a macro, since nothing would force it to be regenerated. Add cmake/scripts/gen_hedley_undef_check.cmake, which derives the full list of JSON_HEDLEY_* macro names directly from include/nlohmann/thirdparty/hedley/hedley.hpp: - tests/CMakeLists.txt uses it (MODE=checks) to (re)generate hedley_undef_checks.inc at configure and build time, and wires the generating custom target as a dependency of the test-no-macro-leak_cpp* targets so it can never build against a stale copy. unit-no-macro-leak.cpp now just #include-s the generated file inside its TEST_CASE instead of carrying the checks itself. - The Makefile's `update_hedley` target now delegates hedley_undef.hpp generation to the same script (MODE=undef, new `update_hedley_undef` target), so the vendored header, the generated #undef list, and the generated test checks are all derived from the same extraction logic and cannot drift apart. This mirrors the approach taken independently in #5415 for the same issue (#5408), credited there to a self-regenerating mechanism that "can never drift again" -- ported into this branch instead of the static list originally proposed here. Verified with a local CMake configure + build + ctest, both against include/ (JSON_MultipleHeaders=ON) and against the amalgamated single_include/nlohmann/json.hpp (JSON_MultipleHeaders=OFF), and by temporarily deleting a #undef line from hedley_undef.hpp to confirm the generated test actually fails on a real leak. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix REUSE compliance failure in gen_hedley_undef_check.cmake The generated file's embedded banner contains the literal text 'SPDX-License-Identifier: MIT' as part of the *content* being written to hedley_undef.hpp, not as this .cmake script's own REUSE header (it is already covered by the blanket 'Files: *' rule in .reuse/dep5). The reuse tool matched that embedded line as an SPDX tag for the script itself and failed to parse the trailing 'MIT\n")' as a valid SPDX License Expression, breaking ci_reuse_compliance. Wrap the embedded banner in REUSE-IgnoreStart/REUSE-IgnoreEnd comments, as recommended by the tool's own diagnostic output. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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Niels Lohmann
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855f511db4 |
Fix stale Clang -Weverything suppression comments; drop -Wno-missing-noreturn (#5250)
* Fix stale Clang -Weverything suppression comments; eliminate -Wno-missing-noreturn cmake/clang_flags.cmake claimed -Wno-unsafe-buffer-usage was needed only for Doctest and that -Wno-missing-noreturn had "no way to silence... otherwise" (PR #4871, which never actually attempted a source fix). Neither held up under investigation (todo 130): - -Wno-unsafe-buffer-usage is pervasive (208 distinct sites across 19 files measured with clang trunk in silkeh/clang:dev), spanning the library's own low-level numeric/buffer code (to_chars, serializer, lexer, binary reader/writer, input adapters, json_pointer) as well as vendored Doctest itself (96 of the 208 sites). A source-level fix is not feasible at this scale; the comment now says so instead of blaming Doctest alone. - -Wno-missing-noreturn had exactly two real trigger sites, both genuinely and unconditionally non-returning: a test-only throwing allocator (tests/src/unit-allocator.cpp) and, previously undiscovered, wide_string_input_adapter::get_elements<T>() in include/nlohmann/detail/input/input_adapters.hpp. Verified this isn't a wider pattern by checking all 160 JSON_THROW call sites in the library for functions whose entire body is an unconditional throw. Annotated both ([[noreturn]] in the test file, since JSON_HEDLEY_NO_RETURN is #undef'd by the time test code runs; JSON_HEDLEY_NO_RETURN in the library file, its first real use anywhere in the codebase) and dropped the suppression entirely. single_include/nlohmann/json.hpp regenerated via `make amalgamate`; `make check-amalgamation` passes. Verified in Docker (silkeh/clang:dev, matching the ci_static_analysis_clang CI job): baseline builds clean, and the full 194-target test suite builds with zero warnings under the corrected CLANG_CXXFLAGS (-Wno-missing-noreturn no longer in the list). Also sanity-compiled and ran unit-allocator.cpp and unit-wstring.cpp on host Apple Clang to confirm behavior is unchanged. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Fix MSVC C4702 warning caused by JSON_HEDLEY_NO_RETURN on get_elements() PR #5250 annotated wide_string_input_adapter::get_elements<T>() with JSON_HEDLEY_NO_RETURN (it unconditionally throws). On MSVC this expands to __declspec(noreturn), and MSVC correctly determined that the code following its call in binary_reader.hpp is unreachable for that instantiation, firing C4702 under /W4 /WX in the msvc, msvc-vs2026, and msvc-arm64 Debug jobs. Clang doesn't flag this case, so the Docker verification for #5250 (which only checked Clang -Weverything) didn't catch it. This is the same warning class already tolerated for Release builds since PR #5216, where MSVC's optimizer independently found the same dead code after /Od was removed. Extend that existing /wd4702 suppression to Debug builds too, instead of reverting the noreturn annotation. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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Niels Lohmann
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8d7e0046f4 |
Add std::format and fmt support (#5224)
* ✨ add std::format and fmt support Signed-off-by: Niels Lohmann <mail@nlohmann.me> * ♻️ reorganize PR Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 💚 fix build Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 💚 fix build Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 💚 fix build Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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Niels Lohmann
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272411c5e6 |
Overwork project infrastructure (#5218)
* 📝 overwork project infrastructure Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🐛 fix GCC16 issue Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🐛 fix GCC16 issue Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🐛 only build module for GCC Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 🐛 fix build Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 📝 fix documentation Closes #5012: fix the error_handler_t::ignore wording Signed-off-by: Niels Lohmann <mail@nlohmann.me> * 📝 fix documentation Closes #4354: fix "Custom data source" example Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me> |
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  risa2000andRichard Musil
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c37f82e563 |
Remove forced /Od flag in MSVC Release build. (#5216)
Add /wd4702 to disable warning C4702: unreachable code in MSVC Release build. Signed-off-by: Richard Musil <risa2000x@gmail.com> Co-authored-by: Richard Musil <risa2000x@gmail.com> |
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risa2000andRichard Musil
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11aa5f944d |
Make std::filesystem::path conversion to/from UTF-8 encoded string explicit (#4631)
* Make std::filesystem::path conversion to/from UTF-8 encoded JSON string explicit. Signed-off-by: Richard Musil <risa2000x@gmail.com> * Experimental: Changing C++ standard detection logic to accommodate potential corner cases. Signed-off-by: Richard Musil <risa2000x@gmail.com> * Drop C++ standard tests for compilers which do not implement required features. Signed-off-by: Richard Musil <risa2000x@gmail.com> * Drop C++ standard tests for MSVC versions which do not implement required features. Signed-off-by: Richard Musil <risa2000x@gmail.com> --------- Signed-off-by: Richard Musil <risa2000x@gmail.com> Co-authored-by: Richard Musil <risa2000x@gmail.com> |
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 Craig Scott
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fac07e22c5 |
Accept NEW CMake policies up to CMake 3.14 (#4112)
Starting with CMake 3.27, deprecation warnings are issued when asking for policy settings for CMake 3.4 or earlier. The cmake_minimum_required() command accepts a version range, which allows NEW policy settings up to the upper end of that range to be used, but without raising the minimum CMake version above the bottom of that range. This means NEW policy settings will be used where available, without requiring them. This change updates the project's cmake_minimum_required() calls to use a version range to extend the upper policy version to 3.14 where it wasn't already at that version or higher. This prevents the deprecation warning from CMake 3.27, and gives breathing space before a future CMake release will start issuing similar deprecation warnings again. |
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  Raphael Grimmandbarcode
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233d233439 |
Fix CI issues (#3906)
Co-authored-by: barcode <barcode@example.com> |
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 Florian Albrechtskirchinger
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0c7a18374c |
Reimplement value() access functions (#3663)
* Reimplement value() access functions * Merges the 'const char *' with the 'ValueType &&' overloads. * Fixes ambiguities when default value is 0. * Fixes 'no matching function' error when specifying ValueType template parameter. * Fixes incorrect template parameter order in previous overloads. * Add additional value() tests * Make JSON_MultipleHeaders visible to unit tests Define the macro JSON_TEST_USING_MULTIPLE_HEADERS to 0/1 depending on JSON_MultipleHeaders. * Add type_traits unit test * Update documentation |
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Florian Albrechtskirchinger
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a2578d1d50 | Disable exceptions on ICPC (#3621) | ||
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Florian Albrechtskirchinger
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d909f80960 |
Add versioned, ABI-tagged inline namespace and namespace macros (#3590)
* Add versioned inline namespace Add a versioned inline namespace to prevent ABI issues when linking code using multiple library versions. * Add namespace macros * Encode ABI information in inline namespace Add _diag suffix to inline namespace if JSON_DIAGNOSTICS is enabled, and _ldvcmp suffix if JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON is enabled. * Move ABI-affecting macros into abi_macros.hpp * Move std_fs namespace definition into std_fs.hpp * Remove std_fs namespace from unit test * Format more files in tests directory * Add unit tests * Update documentation * Fix GDB pretty printer * fixup! Add namespace macros * Derive ABI prefix from NLOHMANN_JSON_VERSION_* |
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Florian Albrechtskirchinger
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5520761433 |
Fix Unicode test timeout (for real this time!) (#3614)
* Use TIMEOUT instead of TIMEOUT_AFTER_MATCH to set test timeout |
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Florian Albrechtskirchinger
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71bdaf5748 |
Enable overriding test properties and set Unicode test timeouts (#3580)
* CMake: Add TEST_PROPERTIES to json_test_set_test_options() Allow overriding test properties via json_test_set_test_options(). * CMake: Set timeouts for Unicode tests |
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Florian Albrechtskirchinger
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e80945da2c |
CI: Enable 32bit unit test (3) (#3532)
* Enable JSON_MultipleHeaders by default * CI: Add single-header build * CI: Enable 32bit unit test * Fix "-Wuseless-cast" warnings * Remove coverage exclusion * Fix 32bit test case |
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 Florian AlbrechtskirchingerandQianqian Fang
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48a102c2c5 |
Fix ndarray dimension signedness, fix ndarray length overflow (2); add 32bit unit test (#3523)
* Fix ndarray dimension signness, fix ndarray length overflow, close #3519 * detect size overflow in ubjson and bjdata * force reformatting * Fix MSVC compiler warning * Add value_in_range_of trait * Use value_in_range_of trait * Correct 408 parse_errors to out_of_range * Add 32bit unit test The test can be enabled by setting JSON_32bitTest=ON. * Exclude unreachable lines from coverage Certain lines are unreachable in 64bit builds. Co-authored-by: Qianqian Fang <fangqq@gmail.com> |
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Florian Albrechtskirchinger
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6b97599a27 |
Fix C++20/gcc-12 issues (Part 2) (#3446)
* Add C++20 3-way comparison operator and fix broken comparisons Fixes #3207. Fixes #3409. * Fix iterators to meet (more) std::ranges requirements Fixes #3130. Related discussion: #3408 * Add note about CMake standard version selection to unit tests Document how CMake chooses which C++ standard version to use when building tests. * Update documentation * CI: add legacy discarded value comparison * Fix internal linkage errors when building a module |
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6a7392058e |
Complete documentation for 3.11.0 (#3464)
* 👥 update contributor and sponsor list * 🚧 document BJData format * 🚧 document BJData format * 📝 clarified documentation of [json.exception.parse_error.112] * ✏️ adjust titles * 📝 add more examples * 🚨 adjust warnings for index.md files * 📝 add more examples * 🔥 remove example for deprecated code * 📝 add missing enum entry * 📝 overwork table for binary formats * ✅ add test to create table for binary formats * 📝 fix wording in example * 📝 add more examples * Update iterators.md (#3481) * ✨ add check for overloads to linter #3455 * 👥 update contributor list * 📝 add more examples * 📝 fix documentation * 📝 add more examples * 🎨 fix indentation * 🔥 remove example for destructor * 📝 overwork documentation * Updated BJData documentation, #3464 (#3493) * update bjdata.md for #3464 * Minor edit * Fix URL typo * Add info on demoting ND array to a 1-D optimized array when singleton dimension Co-authored-by: Chaoqi Zhang <prncoprs@163.com> Co-authored-by: Qianqian Fang <fangqq@gmail.com> |
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Florian AlbrechtskirchingerandNiels Lohmann
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bdc21ad1a7 |
Add build step for ICPC (with fixes) (#3465)
* ⬆️ Doctest 2.4.7 * 👷 add CI step for ICPC * 👷 add CI step for ICPC * 👷 add CI step for ICPC * ⬇️ downgrade to Doctest 2.4.6 * 👷 add CI step for ICPC * 👷 add CI step for ICPC * 👷 add CI step for ICPC * 👷 add CI step for ICPC * 👷 add CI step for ICPC * 🔇 suppress warning #2196: routine is both "inline" and "noinline" * Re-enable <filesystem> detection on ICPC * Limit regression test for #3070 to Clang and GCC >=8.4 * Disable deprecation warnings on ICPC * Disable regression test for #1647 on ICPC (C++20) * Fix compilation failure of regression test for #3077 on ICPC * Disable wstring unit test on ICPC Fixes: error 913: invalid multibyte character sequence * Add ICPC to README Co-authored-by: Niels Lohmann <mail@nlohmann.me> |
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Niels Lohmann
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b21c345179 |
Reorganize directories (#3462)
* 🚚 move files * 🚚 rename doc folder to docs * 🚚 rename test folder to tests |