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Author SHA1 Message Date
Niels Lohmann d1d0e303a0 Report one-character non-numeric array indices like basic_json in the view
Develop's #5800 made basic_json report a JSON pointer array index such as
"/a" as parse_error.109 instead of out_of_range.404, as longer ones were;
the view's array_index() follows, with "-" and the empty token still
unresolved.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 12:44:42 +02:00
Niels Lohmann 7f3ba5a5bc Regenerate the amalgamated headers
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:42 +02:00
Niels Lohmann 51ad02a5a1 Fix the clang-tidy 22 findings in json_view and its tests
The same changes as on the dump branch, where they were first made, so
that this branch passes clang-tidy on its own.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:41 +02:00
Niels Lohmann 7d475ebdc2 Make json_view.hpp pass include-what-you-use
ci_single_binaries runs IWYU with --error on every header. For json_view.hpp
it suggested adding <array> (std::array is used), the headers that json.hpp
already provides (abi_config, abi_macros, input_adapters, json_pointer,
cpp_future, string_concat, value_t, json_fwd), and <version> for
std::nullptr_t, and removing <cstddef>.

- include <array>
- keep <cstddef> (nullptr_t, size_t; IWYU attributes them to <version> and <cstring>)
- tell IWYU not to suggest the headers that json.hpp provides: the amalgamated
  json_view.hpp only includes json.hpp, so including them here would duplicate
  their definitions

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:41 +02:00
Niels Lohmann d1570b9684 Avoid GCC useless-cast warnings in the integer index tests
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:40 +02:00
Niels Lohmann b8529ce4f2 Make json_view.hpp pass include-what-you-use
Mark the includes that are needed by design (json.hpp, the macro
unscope, <tuple> for the tuple_size specialization), take size_t from
<cstring>, and drop the forward declaration of basic_json_document that
the friend declaration makes redundant.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:39 +02:00
Niels Lohmann c5f8e31bd5 Do not force-inline the view's functions on MSVC
__forceinline makes MSVC report C4714 for function templates it cannot
inline (get<std::string>), an error under /WX. The forced inlining is
only a performance hint, so use plain inline there.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:38 +02:00
Niels Lohmann 386a06b59c Return the first member of duplicate keys from lookups again
Looking up the last member of a duplicate key cannot stop at a match, so
every lookup scanned the whole object (1.6 to 3.4 times slower for small
objects). operator[](key), at, find, value, contains, count, and JSON
pointer resolution return the first member again, as yyjson and simdjson
do; materialize() and get<map>() keep the last value, as parse().

The documentation says so in the feature page and on each lookup page,
and explains how to get the value parse() would give. The integer index
templates and the discarded chaining of operator[] stay.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:37 +02:00
Niels Lohmann ac1764b33a Test discarded views with is_discarded() in the operator[] docs and examples
The explicit conversion to bool of basic_json_view is gone.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:36 +02:00
Niels Lohmann e6610e16e6 Use named documents in the json_view tests that called root() on a temporary
root() of an rvalue document is deleted, because the views would dangle.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:35 +02:00
Niels Lohmann 4ef9ca592c Replace the removed operator bool of basic_json_view in the header and its tests
A view is tested with is_discarded(); the lookups in at(), value() and
contains(json_pointer) and the unit tests no longer rely on the explicit
conversion to bool.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:34 +02:00
Niels Lohmann 0eaea7ccba Make view lookups last-wins and chained access safe
* Lookups (operator[], at, find, contains, count, value, JSON pointers)
  return the last member of a duplicate key, as materialize() and
  parse() keep it.
* operator[] on a discarded view returns a discarded view instead of
  throwing, so v["a"]["b"] is safe for a missing "a".
* operator[] and at() take any integer type (not only int and size_t),
  fixing ambiguous calls with unsigned, long, std::int64_t, ...
* Fix the operator[] documentation, which claimed a discarded view for
  a type mismatch where type_error.305 is thrown.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:34 +02:00
Niels Lohmann e8907a55dc Add element access, iteration, values, and JSON pointers to json_view
Give basic_json_view the read-only access functions of basic_json:
operator[] and at() with keys and indices, front()/back(), find(),
contains(), count(), begin()/end() and cbegin()/cend(), items()
with structured bindings from C++17 on, and type_name().

Exceptions have the ids and messages of the const functions of
basic_json. Where basic_json has undefined behavior the view
answers safely: operator[] with a missing key or an out-of-range
index returns a discarded view, and front()/back() of an empty
container throw invalid_iterator.214. Objects are iterated in
document order, and all members are visited; duplicate-key lookups
find the first member (as yyjson and simdjson do), while parse(),
materialize(), and the map conversions keep the last value, as
parse() does. Keys of up to 16 bytes are compared with two
overlapping loads.

Add value conversions: get<T>()/get_to() for arithmetic types,
bool, nullptr_t, strings (std::basic_string copied,
string_view_t without a copy), BasicJsonType, views, std::vector,
and maps with string keys; get_string() for the string without a
copy; number_token() for the number exactly as written in the
source; value() with keys and JSON pointers; and operator[]/at()/
contains() with JSON pointers. Everything else, including types
with from_json(), goes through materialize() of that subtree.
get<T>() of arithmetic types is inlined down to the conversion, so
reading an integer needs no call.

detail::json_pointer_access exposes a pointer's reference tokens
to code outside basic_json.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:33 +02:00
Niels Lohmann ae33774146 Regenerate the amalgamated headers
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:30 +02:00
Niels Lohmann e9716d3d3d Silence a clang-tidy use-after-move finding in the json_view test
const_text is const, so std::move does not move from it; the second call
is part of the const rvalue test.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:30 +02:00
Niels Lohmann 2491be2a64 Read the node array base after emit() in the view builder's open()
emit() moves the node array when it grows, and the subtraction read base
in the same expression, so the order was unspecified. MSVC Release builds
without forced inlining read the old base; the container index then
pointed outside the array and close() wrote out of bounds.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:29 +02:00
Niels Lohmann f9b45bc087 Make json_view.hpp pass include-what-you-use
ci_single_binaries runs IWYU with --error on every header. For json_view.hpp
it suggested adding <array> (std::array is used), the headers that json.hpp
already provides (abi_config, abi_macros, input_adapters, json_pointer,
cpp_future, string_concat, value_t, json_fwd), and <version> for
std::nullptr_t, and removing <cstddef>.

- include <array>
- keep <cstddef> (nullptr_t, size_t; IWYU attributes them to <version> and <cstring>)
- tell IWYU not to suggest the headers that json.hpp provides: the amalgamated
  json_view.hpp only includes json.hpp, so including them here would duplicate
  their definitions
- export json.hpp, keep macro_unscope.hpp, and drop the unused forward declaration of the document class

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:28 +02:00
Niels Lohmann 009eb71a47 Make max_input_size a function (GCC -Wunused-const-variable)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:27 +02:00
Niels Lohmann 38f5c0cc69 Check the steps of the deep-nesting test separately
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:26 +02:00
Niels Lohmann 0000cccf0b Suppress Flawfinder's read() finding on the deleted overload
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:25 +02:00
Niels Lohmann bb17f8a324 Annotate intentional patterns in unit-json_view.cpp for clang-tidy
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:24 +02:00
Niels Lohmann f5710b21b5 Fix clang-tidy findings in unit-json_view_builder.cpp
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:24 +02:00
Niels Lohmann e084f69357 Give document_data a user-provided constructor
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:23 +02:00
Niels Lohmann a491a9137b Fuzz json_document with exact-size buffers and parse options
The fuzzer only parsed a std::string with default options. Also parse an
exact-size byte vector, which has no NUL after its last byte and takes the
bounds-checked path, and derive ignore_comments and ignore_trailing_commas
from the first input byte, comparing against json::parse and json::accept
with the same options.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:22 +02:00
Niels Lohmann aed12fbad2 Align the banner comment of json_view.hpp
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:21 +02:00
Niels Lohmann 1d7c9125a3 Remove the unused legacy_discarded_value_comparison from abi_config
Nothing reads it: the view does not compare values.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:20 +02:00
Niels Lohmann 20d76ebf87 State the exact input size limit of json_document
The check rejects inputs of 0xFFFFFFF0 bytes or more, but the exception
message and the documentation said 4 GiB. Name the limit once
(max_input_size), and state 4 GiB minus 16 bytes in the message and the
documentation. Test the limit with a container that only claims the size.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:19 +02:00
Niels Lohmann f2fa7ea661 Check the node array size for overflow
reserve(n) and the growth of the index computed n * sizeof(node) without a
check, which wraps around on 32-bit targets for inputs of about 1 GiB and
allocates a too small array. Throw std::bad_alloc for a count beyond the
address space and clamp the growth step to it.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:18 +02:00
Niels Lohmann 2a55c9065b Store node integers by halves on big-endian targets
The non-little-endian path of the node writer wrote the integer's native
word over len and next, so len got the high half there. Compose and split
the value explicitly (len is the low half, next the high half); the
little-endian path stays a plain memcpy.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:17 +02:00
Niels Lohmann b26a898619 Delete json_document::root() on temporary documents
auto v = json_document::parse(text).root() compiled and left the view
dangling. Delete the overload for rvalue documents, take a named document
in the tests, and document the lifetime rule.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:17 +02:00
Niels Lohmann 2d1f109f8b Remove the conversion to bool from json_view
explicit operator bool meant "refers to a value", which silently differs
from what a basic_json converts to. Use !v.is_discarded() instead.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:16 +02:00
Niels Lohmann 882675320b Copy const rvalue strings and document the accepted inputs
json_document::parse(std::move(const_string)) failed to compile with
"no matching read_kind": only a non-const rvalue std::string can be moved
from. Treat a const rvalue as a copied byte container.

parse() does not accept everything BasicJsonType::parse() does: a FILE*
and pointers to or arrays of wide characters are rejected at compile time.
List the supported inputs instead.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:15 +02:00
Niels Lohmann d449861523 Reject integer lengths in json_document::parse
parse(ptr, len) compiled: len converted to allow_exceptions, and ptr was
read as a C string, past the end of a buffer without a terminating NUL.
Delete the overloads of parse, parse_copy, accept, and read that take an
integer other than bool where the flags are expected.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:14 +02:00
Niels Lohmann 54528c28c2 Exclude libstdc++'s string_view comparison from the sign-change check
basic_string_view::_S_compare stores the difference of two lengths in a
signed difference_type on purpose, which -fsanitize=integer reports for
every comparison with a shorter view (test-json_view_cpp17).

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:13 +02:00
Niels Lohmann adb623649b Fix document_data for old Clang (3.4-3.6)
Drop the empty braced NSDMIs of the std::string members: old Clang
rejects the defaulted constructor when it is used by a member
initializer before the end of the class definition.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:12 +02:00
Niels Lohmann 5bc36a6947 Add json_document and json_view: node index, parser, and document
Add json_document and json_view, a read-only, zero-copy index of a
JSON text, as the first public slice of the zero-copy view (#5295).

A parse produces a flat array of 16-byte nodes in document order,
one per value and one per object key. Strings stay in the source
text; escaped strings are decoded into an arena. Integers are
converted while their digits are in the cache; floats keep only
their digit layout and are converted on read. Containers store the
size of their subtree, so a reader can step over one in constant
time. A document makes a handful of allocations, however many
values it has.

The parser accepts exactly what json::parse accepts, with every
combination of ignore_comments and ignore_trailing_commas, with and
without a trailing NUL, and under JSON_STRICT_NUL_HANDLING. It is
portable C++11 and does not depend on byte order.

basic_json_document adds parse, parse_copy, accept, read (reuses a
document's memory), root, is_discarded, source, owns_source,
node_count, memory_usage, and shrink_to_fit. basic_json_view adds
type, the is_* queries, operator bool, size, empty, materialize,
and source_offset. A parse error throws the same exception
basic_json::parse would throw for the same input, message and
position included.

detail::abi_config keeps JSON_STRICT_NUL_HANDLING and
JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON readable after json.hpp
undefines them, in the ABI namespace so they always match the
basic_json in use.

A NUL byte that ends a // comment is the end of the input, as in
parse() since #5696.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:11 +02:00
Niels Lohmann 05e11ce350 Regenerate the amalgamated headers
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:09 +02:00
Niels Lohmann 087885f142 Silence MSVC C4127 for a platform-constant check in the to_chars test
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:08 +02:00
Niels Lohmann dc01cc02e2 Credit Zmij's authors in to_chars.hpp, the README, and the license page
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:07 +02:00
Niels Lohmann 007dfb0742 Select the Zmij conversion by a trait, not by the double overload
The non-template overloads for double asserted binary64 doubles wherever json.hpp was included, so the library no longer compiled where double is not IEEE 754 binary64 (AVR, -fshort-double). A trait now picks Zmij for any binary64 type, including a long double of that format (MSVC, Apple Arm), and Grisu2 for the others. Remove the unused write_short_decimal, powers_of_ten_16, zmij::decimal, zmij::to_decimal, and shortest_digits(double).

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:07 +02:00
Niels Lohmann a44c80c6ce Fix CI findings in the Zmij writer and its tests
- bit_ops.hpp: include macro_scope.hpp (JSON_HEDLEY_ALWAYS_INLINE); fixes IWYU
- to_chars.hpp: C4100 for the unused parameter in release builds, clang-tidy
  sign comparison, cpplint runtime/int, GCC -Wstrict-overflow (unsigned abs)
- unit-to_chars.cpp: parse with the library instead of strtod (MinGW's strtod
  rounds some 16/17 digit inputs wrongly); no floating-point std::to_chars
  with icpc

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:06 +02:00
Niels Lohmann f6895fb84e Write doubles with the shortest digits (Żmij), digits in registers
Write doubles with the conversion of Zmij by Victor Zverovich (MIT),
ported to C++11 (detail/conversions/zmij.hpp). It finds the
shortest decimal that reads back as the same double, and the
closest one if there are several. Grisu2, used until now, is fast
but not always shortest: it sometimes writes a 17th digit where 16
suffice, or a last digit that is not the closest. The layout is
unchanged (1.5, 100.0, 1e+100, -0.0); float keeps Grisu2.

Digits are converted eight at a time with the BCD conversion of
Xiang JunBo, as in Zmij, and written with one byte swap per eight
digits and fixed-size moves instead of per-digit loops. Leading and
trailing zeros are counted from those bytes. to_chars() uses a
local buffer when the caller's is shorter than the 41 bytes this
may write. The powers of ten come from the number-parsing table,
adjusted where it holds values rounded up, and extended with Zmij's
compressed tables beyond 10^308.

write_shortest() converts its 16 digits in one vector register
(SSE2 on x86-64, NEON on 64-bit Arm, both baseline) and inserts the
decimal point inside the register, avoiding a store-forwarding
stall that cost about 25% of the time to write a double. dump()
writes floats and integers straight into the serializer's write
buffer instead of copying them from a member buffer, and small
integers eight digits at a time. read_eight_bytes() and
parse_eight_digits() are marked always-inline, which GCC had been
calling out of line in the number-parsing loops.

Of one million random doubles, about 0.14% are now written with
different digits, always to a value that still reads back as the
same double.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:30:05 +02:00
Niels Lohmann 247b03b2de Regenerate the amalgamated headers
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:29:57 +02:00
Niels Lohmann 56ff716d88 Mark the unsigned long of the MSVC bit scans for cpplint
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:29:56 +02:00
Niels Lohmann 9bbd0dafb0 Fix clang-tidy 22 findings in unit-class_lexer.cpp
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:29:55 +02:00
Niels Lohmann 1c8437a724 Reword float conversion notes for the string type and number_float_t docs
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:29:54 +02:00
Niels Lohmann 934f6644d7 Load string scan words with memcpy and use MSVC bit-scan intrinsics
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:29:53 +02:00
Niels Lohmann 1795f59f10 Fix CI warnings in own float parser
- pow5_table.hpp: pow5_128_largest_power was unused in this branch's
  own code (GCC -Werror=unused-const-variable); tie it to the table
  size with a static_assert instead of removing it, since a later
  branch in the stack (json-view/23-zmij) uses it.
- number_parse.hpp: rename the local variable `copy` to `buffer` to
  satisfy cpplint's build/include_what_you_use check.
- unit-class_lexer.cpp: extend the NOLINT list on the seeded mt19937
  with bugprone-random-generator-seed, and parenthesize
  `8 * sizeof(Bits) - 1` for clang-tidy.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:29:53 +02:00
Niels Lohmann 2434cb6e72 Speed up the lexer: own float parser, string scan, and \u table
Give the library its own correctly rounded float converter for
binary32 and binary64 (IEEE 754), and speed up the lexer's string
and escape scanning.

The converter splits a number token into sign, significand, and
decimal exponent, then tries Clinger's fast path, then a templated
Eisel-Lemire step, and falls back to an exact big-integer digit
comparison for tokens with more than 19 significant digits whose two
candidate values round differently. This replaces std::from_chars
and strtod/strtof for both formats, so parsed values no longer
depend on the C/C++ library or the current locale. The strtold
fallback kept for other long double formats (x87, binary128) now
also copies a multi-byte decimal point correctly, fixing #5660.
eisel_lemire() and decimal_to_float() are always inlined so callers
keep the whole conversion in their hot loop.

The string-scanning kernels in string_scan.hpp find a stop byte with
the trailing-zero count of the SWAR mask instead of a byte loop, and
scalar_string_bulk_run() validates a run of multi-byte UTF-8
sequences one after another instead of re-searching after each one.

get_codepoint() decodes a contiguous \uXXXX escape with one table
lookup per byte instead of four range-checked get() calls; the
streaming path and all error positions are unchanged.

Adds 508 generated hard float-parsing cases with expected binary32
and binary64 bits, and kernel-comparison tests for the string scans
and the escape table against byte-by-byte references.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-11 11:29:52 +02:00
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@@ -1,33 +1,3 @@
# Style or vendor rule sets that do not fit a header-only library:
# altera-*, fuchsia-*, llvmlibc-*, android-cloexec-fopen, boost-use-ranges, llvm-header-guard,
# llvm-include-order, llvm-prefer-static-over-anonymous-namespace, llvm-use-ranges,
# misc-use-anonymous-namespace, google-runtime-float, google-runtime-int, hicpp-signed-bitwise,
# bugprone-signed-bitwise, hicpp-explicit-conversions, google-explicit-constructor,
# cppcoreguidelines-explicit-constructor, misc-explicit-constructor (implicit conversions are the
# API), readability-trailing-comma,
# hicpp-avoid-goto / cppcoreguidelines-avoid-goto, hicpp-no-array-decay,
# hicpp-uppercase-literal-suffix, readability-uppercase-literal-suffix, modernize-use-trailing-return-type.
# Constructs the library needs on purpose (the library supports C++11 and legacy compilers):
# cppcoreguidelines-macro-usage, cppcoreguidelines-avoid-do-while (macros),
# cppcoreguidelines-pro-bounds-*, cppcoreguidelines-pro-type-reinterpret-cast,
# cppcoreguidelines-pro-type-union-access (parsers, serializers, basic_json's value union),
# cppcoreguidelines-avoid-const-or-ref-data-members, cppcoreguidelines-rvalue-reference-param-not-moved,
# cppcoreguidelines-avoid-non-const-global-variables, misc-non-private-member-variables-in-classes,
# misc-no-recursion (value walks are recursive, bounded by detail::recursion_depth_limit()),
# modernize-type-traits, modernize-use-constraints, modernize-use-ranges, modernize-use-std-numbers,
# modernize-use-designated-initializers, modernize-use-nodiscard, modernize-concat-nested-namespaces,
# readability-redundant-typename, readability-redundant-parentheses,
# readability-redundant-access-specifiers, readability-simplify-boolean-expr,
# readability-use-concise-preprocessor-directives, modernize-use-string-view,
# modernize-use-integer-sign-comparison (needs std::cmp_less; the flagged
# static_cast<std::size_t>(end - pos) < n comparisons are deliberate)
# (all need a newer standard or compiler than C++11, or would change macro-generated or
# deliberately explicit code).
# Too noisy to be useful (numeric parsing/formatting code, doctest, tests):
# bugprone-easily-swappable-parameters, cppcoreguidelines-avoid-magic-numbers, readability-magic-numbers,
# readability-identifier-length, readability-function-cognitive-complexity, performance-enum-size,
# concurrency-mt-unsafe, misc-confusable-identifiers, misc-include-cleaner (run on its own for
# the consumer headers in cmake/ci.cmake).
# portability-avoid-pragma-once: kept disabled on purpose. #pragma once is accepted
# by every supported compiler, and tools/amalgamate/amalgamate.py strips it from
# single_include, so there is nothing left to fix here.
@@ -40,14 +10,14 @@ Checks: '*,
-android-cloexec-fopen,
-boost-use-ranges,
-bugprone-easily-swappable-parameters,
-bugprone-signed-bitwise,
-cert-err58-cpp,
-clang-analyzer-webkit.NoUncountedMemberChecker,
-concurrency-mt-unsafe,
-cppcoreguidelines-avoid-const-or-ref-data-members,
-cppcoreguidelines-avoid-do-while,
-cppcoreguidelines-avoid-goto,
-cppcoreguidelines-avoid-magic-numbers,
-cppcoreguidelines-avoid-non-const-global-variables,
-cppcoreguidelines-explicit-constructor,
-cppcoreguidelines-macro-usage,
-cppcoreguidelines-pro-bounds-avoid-unchecked-container-access,
-cppcoreguidelines-pro-bounds-array-to-pointer-decay,
@@ -56,15 +26,19 @@ Checks: '*,
-cppcoreguidelines-pro-type-reinterpret-cast,
-cppcoreguidelines-pro-type-union-access,
-cppcoreguidelines-rvalue-reference-param-not-moved,
-cppcoreguidelines-virtual-class-destructor,
-fuchsia-default-arguments-calls,
-fuchsia-default-arguments-declarations,
-fuchsia-overloaded-operator,
-google-explicit-constructor,
-google-readability-function-size,
-google-runtime-float,
-google-runtime-int,
-hicpp-avoid-goto,
-hicpp-explicit-conversions,
-hicpp-function-size,
-hicpp-no-array-decay,
-hicpp-no-assembler,
-hicpp-signed-bitwise,
-hicpp-uppercase-literal-suffix,
-llvm-header-guard,
@@ -74,7 +48,6 @@ Checks: '*,
-llvmlibc-*,
-misc-use-anonymous-namespace,
-misc-confusable-identifiers,
-misc-explicit-constructor,
-misc-include-cleaner,
-misc-no-recursion,
-misc-non-private-member-variables-in-classes,
@@ -82,22 +55,20 @@ Checks: '*,
-modernize-type-traits,
-modernize-use-constraints,
-modernize-use-designated-initializers,
-modernize-use-integer-sign-comparison,
-modernize-use-nodiscard,
-modernize-use-ranges,
-modernize-use-string-view,
-modernize-use-std-numbers,
-modernize-use-trailing-return-type,
-performance-enum-size,
-portability-avoid-pragma-once,
-readability-function-cognitive-complexity,
-readability-function-size,
-readability-identifier-length,
-readability-magic-numbers,
-readability-redundant-access-specifiers,
-readability-redundant-parentheses,
-readability-redundant-typename,
-readability-simplify-boolean-expr,
-readability-trailing-comma,
-readability-uppercase-literal-suffix,
-readability-use-concise-preprocessor-directives'
-2
View File
@@ -111,8 +111,6 @@ context which existing file needs to be extended, and only very few cases requir
When fixing a bug, edit `unit-regression3.cpp` and add a section referencing the fixed issue.
`unit-regression2.cpp` holds the older tests; the two files exist because a single one grew large enough for the
MinGW linker to fail relocating it, so please keep adding to the smaller file rather than growing the larger one.
Tests that call `sax_parse` go into `unit-sax_parse.cpp` rather than into a large test file: every call instantiates
the parser and the binary reader that recover from errors, which grows a test file considerably.
#### Exceptions
+2 -9
View File
@@ -18,8 +18,7 @@ environment:
matrix:
# The Visual Studio 2017 jobs compile everything with /std:c++17, so they
# only build the C++17 variant of each test, split into two jobs each to
# stay below AppVeyor's 60-minute limit per job. The Visual Studio 2019
# job builds the tests for all standards and is split for the same reason.
# stay below AppVeyor's 60-minute limit per job.
- APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
configuration: Debug
platform: x86
@@ -51,13 +50,7 @@ environment:
configuration: Release
platform: x86
CXX_FLAGS: "/W4 /WX"
CMAKE_OPTIONS: "-DJSON_ImplicitConversions=OFF -DJSON_TestShard=0/2"
GENERATOR: Visual Studio 16 2019
- APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
configuration: Release
platform: x86
CXX_FLAGS: "/W4 /WX"
CMAKE_OPTIONS: "-DJSON_ImplicitConversions=OFF -DJSON_TestShard=1/2"
CMAKE_OPTIONS: "-DJSON_ImplicitConversions=OFF"
GENERATOR: Visual Studio 16 2019
- APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+3 -5
View File
@@ -62,14 +62,12 @@ labels:
- "include/nlohmann/detail/view/.*"
- "single_include/nlohmann/json_view\\.hpp"
- "tests/src/unit-json_view.*"
- "tests/src/json_view_test_helpers\\.hpp"
- "tests/src/fuzzer-(parse_json_view|json_view_image)\\.cpp"
- "tests/benchmarks/json_view/.*"
- "tests/src/fuzzer-parse_json_view\\.cpp"
- "tools/amalgamate/config_json_view\\.json"
- "docs/mkdocs/docs/features/json_view\\.md"
- "docs/mkdocs/docs/api/basic_json_(document|view)/.*"
- "docs/mkdocs/docs/api/(ordered_)?json_(editable_)?(document|view)\\.md"
- "docs/mkdocs/docs/examples/(basic_json_(document|view)__|(ordered_)?json_(editable_)?(document|view)).*"
- "docs/mkdocs/docs/api/(ordered_)?json_(document|view)\\.md"
- "docs/mkdocs/docs/examples/(basic_json_(document|view)__|(ordered_)?json_(document|view)).*"
- "tests/benchmarks/src/benchmarks_view\\.cpp"
- label: "aspect: json_view"
+1 -1
View File
@@ -28,7 +28,7 @@ jobs:
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
+20 -41
View File
@@ -22,7 +22,7 @@ jobs:
runs-on: ubuntu-latest
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
@@ -31,13 +31,13 @@ jobs:
mkdir -p ./pr
echo ${{ github.event.number }} > ./pr/number
echo ${{ github.event.pull_request.user.login }} > ./pr/author
- uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
- uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
with:
name: pr
path: pr/
check:
runs-on: ubuntu-26.04
runs-on: ubuntu-latest
env:
MAIN_DIR: ${{ github.workspace }}/main
INCLUDE_DIR: ${{ github.workspace }}/main/single_include/nlohmann
@@ -46,7 +46,7 @@ jobs:
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
@@ -77,12 +77,13 @@ jobs:
cd $MAIN_DIR
# Built from this PR's own tools/macro_builder/main.cpp, not a
# develop checkout: unlike amalgamate.py, this tool has no other
# source of truth to check against (its own README documents that
# it must reproduce macro_scope.hpp byte for byte), so there is
# nothing to gain from checking out a separate copy, and doing so
# would make this step fail on a PR that adds support for a new
# dispatch table until that PR itself merges to develop.
# develop checkout: unlike amalgamate.py and generate_natvis.py,
# this tool has no other source of truth to check against (its
# own README documents that it must reproduce macro_scope.hpp
# byte for byte), so there is nothing to gain from checking out a
# separate copy, and doing so would make this step fail on a PR
# that adds support for a new dispatch table until that PR itself
# merges to develop.
TMPDIR=$(mktemp -d ./macro_builder_check.XXXXXX)
c++ -std=c++11 tools/macro_builder/main.cpp -o "$TMPDIR/macro_builder"
"$TMPDIR/macro_builder" > "$TMPDIR/paste.hpp"
@@ -145,36 +146,14 @@ jobs:
- name: Regenerate nlohmann_json.natvis
run: |
cd $MAIN_DIR
# The generator and its template are what this check verifies the
# committed natvis file against (which namespaces it lists, and
# what each entry looks like), so run this PR's copy rather than
# the develop checkout's: with develop's, a PR that changes either
# could never pass. generate_natvis.py loads the template from its
# own directory. Like the macro_builder step above, this only runs
# PR content in a job without credentials.
python3 tools/generate_natvis/generate_natvis.py $MAIN_DIR
- name: Check the nlohmann_json.natvis generator options
run: |
cd $MAIN_DIR
# The options for configurations outside the checked-in file write
# to a temporary file, so they do not affect the diff below.
GENERATOR=tools/generate_natvis/generate_natvis.py
python3 $GENERATOR --list-tags
TAG_COUNT=$(python3 $GENERATOR --list-tags | wc -l)
python3 $GENERATOR --abi-tags diag,_dp,_vns --abi-tags _diag --output $RUNNER_TEMP/abi_tags.natvis
grep -q '<!-- Namespace nlohmann::json_abi_diag_dp_vns -->' $RUNNER_TEMP/abi_tags.natvis
grep -q '<!-- Namespace nlohmann::json_abi_diag_dp_vns_v[0-9_]* -->' $RUNNER_TEMP/abi_tags.natvis
test $(grep -c '<!-- Namespace ' $RUNNER_TEMP/abi_tags.natvis) -eq $(( $(grep -c '<!-- Namespace ' nlohmann_json.natvis) + 2 ))
python3 $GENERATOR --all --output $RUNNER_TEMP/all.natvis
test $(grep -c '<!-- Namespace ' $RUNNER_TEMP/all.natvis) -eq $(( (1 << TAG_COUNT) * 2 + 1 ))
if python3 $GENERATOR --abi-tags _unknown --output $RUNNER_TEMP/unknown.natvis; then
echo "generate_natvis.py accepted an unknown ABI tag"
exit 1
fi
# The template is what this check verifies the committed natvis
# file against, so take it from this PR rather than from the
# develop checkout: generate_natvis.py loads the template from its
# own directory, and with develop's copy a PR that changes the
# template could never pass. Like the macro_builder step above,
# this only renders PR content in a job without credentials.
cp tools/generate_natvis/nlohmann_json.natvis.j2 $NATVIS_TOOL_DIR/
python3 $NATVIS_TOOL_DIR/generate_natvis.py $MAIN_DIR
- name: Build patch and check for differences
id: diff
@@ -194,7 +173,7 @@ jobs:
# instead of installing the pinned astyle version locally.
- name: Upload patch
if: steps.diff.outputs.has_diff == 'true'
uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
with:
name: amalgamation-patch
path: patch/amalgamation.patch
+1 -1
View File
@@ -20,7 +20,7 @@ jobs:
timeout-minutes: 30
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
+2 -2
View File
@@ -13,7 +13,7 @@ jobs:
runs-on: ubuntu-22.04
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
@@ -35,7 +35,7 @@ jobs:
dry-run: false
language: c++
- name: Upload Crash
uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
if: failure() && steps.build.outcome == 'success'
with:
name: artifacts
+5 -5
View File
@@ -21,13 +21,13 @@ permissions:
jobs:
CodeQL-Build:
runs-on: ubuntu-26.04
runs-on: ubuntu-latest
permissions:
security-events: write
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
@@ -38,14 +38,14 @@ jobs:
# Initializes the CodeQL tools for scanning.
- name: Initialize CodeQL
uses: github/codeql-action/init@6f2ac81f5cd81fe351a197ba0b00d91d03cd2aee # v4.39.0
uses: github/codeql-action/init@2892aa5e19bbd11bc0cff5427e3b750a04d9e3c2 # v4.38.2
with:
languages: c-cpp
# Autobuild attempts to build any compiled languages (C/C++, C#, or Java).
# If this step fails, then you should remove it and run the build manually (see below)
- name: Autobuild
uses: github/codeql-action/autobuild@6f2ac81f5cd81fe351a197ba0b00d91d03cd2aee # v4.39.0
uses: github/codeql-action/autobuild@2892aa5e19bbd11bc0cff5427e3b750a04d9e3c2 # v4.38.2
- name: Perform CodeQL Analysis
uses: github/codeql-action/analyze@6f2ac81f5cd81fe351a197ba0b00d91d03cd2aee # v4.39.0
uses: github/codeql-action/analyze@2892aa5e19bbd11bc0cff5427e3b750a04d9e3c2 # v4.38.2
@@ -20,7 +20,7 @@ jobs:
pull-requests: write
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
@@ -37,14 +37,6 @@ jobs:
var matchArtifact = artifacts.data.artifacts.filter((artifact) => {
return artifact.name == "pr"
})[0];
// a run that failed before its jobs started (e.g. a stale queued
// run cancelled long after its push) has no artifact to report on
if (!matchArtifact) {
core.notice('Run ${{ github.event.workflow_run.id }} has no "pr" artifact; nothing to comment on.');
core.setOutput('found', 'false');
return;
}
core.setOutput('found', 'true');
var download = await github.rest.actions.downloadArtifact({
owner: context.repo.owner,
repo: context.repo.repo,
@@ -59,11 +51,9 @@ jobs:
# Extract the untrusted PR artifact into a dedicated empty directory and
# read only the two expected files by fixed path afterwards. This avoids a
# malicious archive overwriting workspace files or escaping via ../ paths.
- if: steps.download.outputs.found == 'true'
run: unzip -o pr.zip -d ./pr_artifact
- run: unzip -o pr.zip -d ./pr_artifact
- name: 'Comment on PR'
if: steps.download.outputs.found == 'true'
uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
with:
github-token: ${{ secrets.GITHUB_TOKEN }}
+1 -1
View File
@@ -21,7 +21,7 @@ jobs:
runs-on: ubuntu-latest
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
+3 -4
View File
@@ -31,7 +31,7 @@ jobs:
security-events: write
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
@@ -43,11 +43,10 @@ jobs:
- name: flawfinder_scan
uses: david-a-wheeler/flawfinder@c4216b74cf2639ffa98503768bd6e4299b5440c9 # v2.0.20
with:
# single_include/ is omitted: it is generated from include/ and would report every finding twice
arguments: '--sarif ./cmake ./docs ./include ./src ./tests ./tools'
arguments: '--sarif ./'
output: 'flawfinder_results.sarif'
- name: Upload analysis results to GitHub Security tab
uses: github/codeql-action/upload-sarif@6f2ac81f5cd81fe351a197ba0b00d91d03cd2aee # v4.39.0
uses: github/codeql-action/upload-sarif@2892aa5e19bbd11bc0cff5427e3b750a04d9e3c2 # v4.38.2
with:
sarif_file: ${{github.workspace}}/flawfinder_results.sarif
@@ -1,84 +0,0 @@
name: "json_view benchmarks"
# On demand only: runs the comparison of json_view with yyjson, simdjson, and
# Boost.JSON (tests/benchmarks/json_view/compare.py) on GitHub-hosted runners,
# for numbers from x86-64 and AArch64 Linux. It runs when started by hand, or
# when a pull request gets the label "benchmark" (on both architectures, with
# GCC and the default settings). Shared runners are noisy: the results show
# where json_view stands, but published numbers need a quiet machine (see
# tests/benchmarks/json_view/README.md).
on:
pull_request:
types: [labeled]
workflow_dispatch:
inputs:
runner:
description: "Runner image"
type: choice
options:
- ubuntu-24.04
- ubuntu-24.04-arm
default: ubuntu-24.04
compiler:
description: "Compiler"
type: choice
options:
- g++
- clang++
default: g++
native:
description: "Compile for the runner's CPU (-march=native)"
type: boolean
default: false
rounds:
description: "Rounds of bench_view"
type: number
default: 30
permissions:
contents: read
concurrency:
# (the label is part of the group: adding an unrelated label must not cancel a running benchmark)
group: json-view-benchmarks-${{ github.workflow }}-${{ github.ref }}-${{ github.event.label.name }}
cancel-in-progress: true
jobs:
compare:
if: github.event_name == 'workflow_dispatch' || github.event.label.name == 'benchmark'
strategy:
matrix:
runner: ${{ fromJSON(github.event_name == 'workflow_dispatch' && format('["{0}"]', inputs.runner) || '["ubuntu-24.04", "ubuntu-24.04-arm"]') }}
runs-on: ${{ matrix.runner }}
timeout-minutes: 60
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
with:
egress-policy: audit
- uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
with:
persist-credentials: false
- name: Download test data
run: |
cmake -S . -B build -DJSON_BuildTests=On
cmake --build build --target download_test_data
- name: Run the comparison
env:
CXX: ${{ inputs.compiler || 'g++' }}
CC: ${{ inputs.compiler == 'clang++' && 'clang' || 'gcc' }}
ROUNDS: ${{ inputs.rounds || 30 }}
NATIVE: ${{ inputs.native && '--native' || '' }}
run: python3 tests/benchmarks/json_view/compare.py --data build/test_files --download --rounds "$ROUNDS" $NATIVE
- name: Summary
run: cat tests/benchmarks/json_view/results/*.md >> "$GITHUB_STEP_SUMMARY"
- uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
with:
name: json_view-benchmarks-${{ matrix.runner }}-${{ inputs.compiler || 'g++' }}
path: tests/benchmarks/json_view/results/
+1 -1
View File
@@ -23,7 +23,7 @@ jobs:
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
+1 -1
View File
@@ -37,7 +37,7 @@ jobs:
runs-on: ubuntu-latest
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
+4 -4
View File
@@ -40,7 +40,7 @@ jobs:
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
@@ -50,7 +50,7 @@ jobs:
persist-credentials: false
- name: "Run analysis"
uses: ossf/scorecard-action@fa7117db83c52d787ae5a89f350999701505d78e # v2.5.0
uses: ossf/scorecard-action@2d1146689b8cda280b9bc96326124645441f03bc # v2.4.4
with:
results_file: results.sarif
results_format: sarif
@@ -72,7 +72,7 @@ jobs:
# Upload the results as artifacts (optional). Commenting out will disable uploads of run results in SARIF
# format to the repository Actions tab.
- name: "Upload artifact"
uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
with:
name: SARIF file
path: results.sarif
@@ -80,6 +80,6 @@ jobs:
# Upload the results to GitHub's code scanning dashboard.
- name: "Upload to code-scanning"
uses: github/codeql-action/upload-sarif@6f2ac81f5cd81fe351a197ba0b00d91d03cd2aee # v4.39.0
uses: github/codeql-action/upload-sarif@2892aa5e19bbd11bc0cff5427e3b750a04d9e3c2 # v4.38.2
with:
sarif_file: results.sarif
+3 -3
View File
@@ -33,10 +33,10 @@ jobs:
security-events: write # for github/codeql-action/upload-sarif to upload SARIF results
actions: read # only required for a private repository by github/codeql-action/upload-sarif to get the Action run status
name: Scan
runs-on: ubuntu-26.04
runs-on: ubuntu-latest
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
@@ -65,7 +65,7 @@ jobs:
# Upload SARIF file generated in previous step
- name: Upload SARIF file
uses: github/codeql-action/upload-sarif@6f2ac81f5cd81fe351a197ba0b00d91d03cd2aee # v4.39.0
uses: github/codeql-action/upload-sarif@2892aa5e19bbd11bc0cff5427e3b750a04d9e3c2 # v4.38.2
with:
sarif_file: semgrep.sarif
if: always()
+1 -1
View File
@@ -16,7 +16,7 @@ jobs:
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
+32 -32
View File
@@ -25,20 +25,20 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Run CMake
run: cmake -S . -B build -DJSON_CI=On
- name: Build
run: cmake --build build --target ci_test_gcc
ci_meson_install:
runs-on: ubuntu-26.04
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Check that Meson and pkg-config offer the CMake options
run: make check_build_options
- name: Install Meson
@@ -77,10 +77,10 @@ jobs:
cmake --build build-import-split
ci_infer:
runs-on: ubuntu-26.04
runs-on: ubuntu-latest
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
@@ -92,27 +92,27 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Run CMake
run: cmake -S . -B build -DJSON_CI=On
- name: Build
run: cmake --build build --target ci_infer
- name: Archive Infer report
if: always()
uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
with:
name: infer-report
path: ${{ github.workspace }}/build/build_infer/infer-out/report.txt
if-no-files-found: ignore
ci_static_analysis_ubuntu:
runs-on: ubuntu-26.04
runs-on: ubuntu-latest
strategy:
matrix:
target: [ci_test_single_header, ci_cppcheck, ci_cpplint, ci_reproducible_tests, ci_non_git_tests, ci_offline_testdata, ci_reuse_compliance, ci_test_valgrind]
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
@@ -123,7 +123,7 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Run CMake
run: cmake -S . -B build -DJSON_CI=On
- name: Build
@@ -142,7 +142,7 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Run CMake
run: cmake -S . -B build -DJSON_CI=On
- name: Build
@@ -168,17 +168,17 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Run CMake
run: cmake -S . -B build -DJSON_CI=On
- name: Build
run: cmake --build build --target ${{ matrix.target }}
ci_test_coverage:
runs-on: ubuntu-26.04
runs-on: ubuntu-latest
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
@@ -197,7 +197,7 @@ jobs:
- name: Build
run: cmake --build build --target ci_test_coverage
- name: Archive coverage report
uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
with:
name: code-coverage-report
path: ${{ github.workspace }}/build/html
@@ -244,7 +244,7 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Run CMake
run: CXX=g++-${{ matrix.compiler }} cmake -S . -B build -DJSON_CI=On
- name: Build
@@ -262,7 +262,7 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Run CMake
run: cmake -S . -B build -DJSON_CI=On
- name: Build
@@ -279,7 +279,7 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Disable filesystem support (std::filesystem is unusable) for clang 7 / 8 / 9 / 10
run: echo "JSON_FORCED_GLOBAL_COMPILE_OPTIONS=-DJSON_HAS_FILESYSTEM=0;-DJSON_HAS_EXPERIMENTAL_FILESYSTEM=0" >> "$GITHUB_ENV"
if: ${{ matrix.compiler == '7' || matrix.compiler == '8' || matrix.compiler == '9' || matrix.compiler == '10' }}
@@ -299,7 +299,7 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Run CMake
run: cmake -S . -B build -DJSON_CI=On
- name: Build
@@ -319,7 +319,7 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Run CMake
run: cmake -S . -B build -DJSON_CI=On
- name: Build with libc++
@@ -346,7 +346,7 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Run CMake
run: cmake -S . -B build -DJSON_CI=On
- name: Build
@@ -366,7 +366,7 @@ jobs:
# import-std support. Its opt-in token is CMake-version-specific, so pin
# CMake to the version whose token is set in tests/module_cpp20/CMakeLists.txt.
- name: Get pinned CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
with:
cmakeVersion: 4.3.4
# Clang: the std library module is provided by libc++ (the image's libstdc++
@@ -392,7 +392,7 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Run CMake
run: cmake -S . -B build -DJSON_CI=On
- name: Build
@@ -409,7 +409,7 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Run CMake
run: cmake -S . -B build -DJSON_CI=On
- name: Build
@@ -423,17 +423,17 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Run CMake
run: cmake -S . -B build -DJSON_CI=On
- name: Build
run: cmake --build build --target ci_nvhpc
ci_emscripten:
runs-on: ubuntu-26.04
runs-on: ubuntu-latest
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
@@ -443,20 +443,20 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Run CMake
run: cmake -S . -B build -DCMAKE_TOOLCHAIN_FILE=$EMSDK/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake -GNinja
- name: Build
run: cmake --build build
ci_test_documentation:
runs-on: ubuntu-26.04
runs-on: ubuntu-latest
strategy:
matrix:
target: [ci_test_examples, ci_test_build_documentation, ci_test_documentation_mermaid]
steps:
- name: Harden Runner
uses: step-security/harden-runner@ccd8616d44fd3846e67624a50d5aad6d37bf2d25 # v2.22.1
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
@@ -465,7 +465,7 @@ jobs:
persist-credentials: false
# the git-revision-date-localized plugin needs the history; a shallow clone makes the strict build fail
fetch-depth: ${{ matrix.target == 'ci_test_build_documentation' && '0' || '1' }}
- uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7.1.0
- uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
if: matrix.target == 'ci_test_documentation_mermaid'
with:
node-version: 24
@@ -484,7 +484,7 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Check that the job runs natively on arm64
run: uname -m && test "$(uname -m)" = aarch64
- name: Run CMake
+10 -12
View File
@@ -90,7 +90,7 @@ jobs:
with:
persist-credentials: false
- name: Get latest CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
- name: Set extra CXX_FLAGS for latest std_version
# /wd5285 silences C5285 emitted by the bundled third-party doctest.h, which
# specializes std::tuple (newly diagnosed by the VS2026 v145 toolset)
@@ -166,21 +166,19 @@ jobs:
# 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.
# Keep the objects small by splitting the test files instead.
# The tests link with LLD: GNU ld fails on objects with more than 32767
# sections with "relocation truncated to fit: IMAGE_REL_AMD64_REL32
# against `.rdata'", as it stores the section an associative COMDAT
# section belongs to in 16 bits (x_associated in binutils'
# include/coff/internal.h) and so discards the jump tables of inline
# functions together with the wrong function. Each basic_json
# specialization and input type a test file instantiates adds many
# sections, so unit-msgpack.cpp and unit-regression2.cpp kept crossing
# that limit as the library grew.
# Objects with more than 65535 sections fail to link with "relocation
# truncated to fit: IMAGE_REL_AMD64_REL32 against `.rdata'": the MinGW
# linker stores the section an associative COMDAT section belongs to in
# 16 bits (x_associated in binutils' include/coff/internal.h), so it
# discards the jump tables of inline functions together with the wrong
# function. Each basic_json specialization a test file instantiates adds
# many sections, so test a second one in a file of its own.
- name: Run CMake
run: cmake -S . -B build ^
-DCMAKE_CXX_COMPILER="C:/Program Files/LLVM/bin/clang++.exe" ^
-DCMAKE_CXX_FLAGS="--target=x86_64-w64-mingw32 -stdlib=libstdc++ -pthread" ^
-DCMAKE_CXX_FLAGS_DEBUG="-g0" ^
-DCMAKE_EXE_LINKER_FLAGS="-fuse-ld=lld -lwinpthread" ^
-DCMAKE_EXE_LINKER_FLAGS="-lwinpthread" ^
-G"MinGW Makefiles" ^
-DCMAKE_BUILD_TYPE=Debug ^
-DJSON_BuildTests=On
@@ -216,7 +214,7 @@ jobs:
# import-std support. Its opt-in token is CMake-version-specific, so pin
# CMake to the version whose token is set in tests/module_cpp20/CMakeLists.txt.
- name: Get pinned CMake and ninja
uses: lukka/get-cmake@a89e43e22a96abafcd7a62db652a65ecd33052c9 # v4.4.4
uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
with:
cmakeVersion: 4.3.4
# CMAKE_CXX_FLAGS replaces CMake's MSVC defaults (which include /EHsc), and
-3
View File
@@ -60,6 +60,3 @@ MODULE.bazel.lock
/json.tar.xz.asc
/release_files/
/single_include/nlohmann/*.asc
# GCC module cache
/gcm.cache/
-4
View File
@@ -1,7 +1,6 @@
{
"_comment": "Used by the ci_infer CMake target (#5715 item 4b). fail-on-issue makes CI fail on Infer findings; disable-issue-type is a type-level baseline for the ~174 pre-existing findings (all PULSE_UNNECESSARY_COPY*/PULSE_RESOURCE_LEAK/PULSE_CONST_REFABLE, mostly in test code) triaged in run https://github.com/nlohmann/json/actions/runs/35829411620 on commit 1054b2097, so CI fails only on a NEW issue type. Remove an entry here once its findings have been fixed or explicitly accepted.",
"_comment_pulse": "Pulse stops exploring paths after pulse-max-disjuncts (default 20). With the default, basic_json::replace_value() (destroy + assert_invariant) exceeds the limit, Pulse loses the stored type, and reports false NULLPTR_DEREFERENCE findings for get_ptr() results in tests/src/unit-pointer_access.cpp.",
"_comment_view": "Infer's model of std::unique_ptr mixes up values that are returned by value and own one: basic_json_document (parse() results) and the `built` values of the build() helper in tests/src/unit-json_view_builder.cpp. It reports USE_AFTER_DELETE for one of them after the destructor of an unrelated object (e.g. ~built() on line 345 invalidating `shallow` on line 350 of that file, or two documents parsed in one lambda in tests/src/unit-json_view_dump.cpp). AddressSanitizer and Valgrind are clean on the same tests, so reports for the json_view test files are excluded; findings reported in the library headers are still reported.",
"pulse-max-disjuncts": 40,
"fail-on-issue": true,
"disable-issue-type": [
@@ -11,8 +10,5 @@
"PULSE_UNNECESSARY_COPY_OPTIONAL",
"PULSE_RESOURCE_LEAK",
"PULSE_CONST_REFABLE"
],
"report-block-list-path-regex": [
"tests/src/unit-json_view.*\\.cpp"
]
}
-8
View File
@@ -37,7 +37,6 @@ cc_library(
"include/nlohmann/detail/input/parser.hpp",
"include/nlohmann/detail/input/position_t.hpp",
"include/nlohmann/detail/input/pow5_table.hpp",
"include/nlohmann/detail/input/simd_scan.hpp",
"include/nlohmann/detail/input/string_scan.hpp",
"include/nlohmann/detail/iterators/internal_iterator.hpp",
"include/nlohmann/detail/iterators/iter_impl.hpp",
@@ -69,12 +68,8 @@ cc_library(
"include/nlohmann/detail/string_utils.hpp",
"include/nlohmann/detail/value_t.hpp",
"include/nlohmann/detail/view/builder.hpp",
"include/nlohmann/detail/view/compare.hpp",
"include/nlohmann/detail/view/document_data.hpp",
"include/nlohmann/detail/view/edit.hpp",
"include/nlohmann/detail/view/edit_storage.hpp",
"include/nlohmann/detail/view/errors.hpp",
"include/nlohmann/detail/view/image.hpp",
"include/nlohmann/detail/view/input.hpp",
"include/nlohmann/detail/view/iterator.hpp",
"include/nlohmann/detail/view/lookup.hpp",
@@ -83,11 +78,8 @@ cc_library(
"include/nlohmann/detail/view/materialize.hpp",
"include/nlohmann/detail/view/node.hpp",
"include/nlohmann/detail/view/number.hpp",
"include/nlohmann/detail/view/object_index.hpp",
"include/nlohmann/detail/view/pointer.hpp",
"include/nlohmann/detail/view/scan.hpp",
"include/nlohmann/detail/view/serializer.hpp",
"include/nlohmann/detail/view/simd.hpp",
"include/nlohmann/detail/view/string_ref.hpp",
"include/nlohmann/detail/view/value.hpp",
"include/nlohmann/json.hpp",
-27
View File
@@ -6,7 +6,6 @@ This file describes the source for supporting files; that is, files that are not
- [GitHub](#github)
- [REUSE](#reuse)
- [Package Managers](#package-managers)
- [Debugging](#debugging)
## Continuous Integration
@@ -290,29 +289,3 @@ The module definition for [Bazel](https://bazel.build)'s [Bzlmod](https://bazel.
Further documentation:
- [Bazel modules](https://bazel.build/external/module)
## Debugging
### `nlohmann_json.natvis`
The [Natvis](https://learn.microsoft.com/en-us/visualstudio/debugger/create-custom-views-of-native-objects) file that
gives `json` values a friendly view in the Visual Studio debugger. The file is generated by
`tools/generate_natvis/generate_natvis.py` from the template `tools/generate_natvis/nlohmann_json.natvis.j2` and the ABI
tags and version in `include/nlohmann/detail/abi_macros.hpp`; change the script or the template rather than editing
the file by hand. The file can be updated by calling
```shell
make natvis
```
The "Check amalgamation" workflow fails if the file is out of date.
The file covers the namespace variants with up to two ABI tags. A Natvis file for other configurations can be
generated with the `--abi-tags` or `--all` options, for example
`make natvis NATVIS_ARGS="--abi-tags _diag,_dp,_vns --output my_nlohmann_json.natvis"`; see
[`tools/generate_natvis`](tools/generate_natvis/README.md). With MSVC, CMake adds the file to the `nlohmann_json`
target and installs it.
Further documentation:
- [Create custom views of C++ objects in the debugger using the Natvis framework](https://learn.microsoft.com/en-us/visualstudio/debugger/create-custom-views-of-native-objects)
+2 -4
View File
@@ -46,7 +46,7 @@ all:
@echo "clean - remove built files"
@echo "(fuzzers) - see tests/fuzzing.md, or run 'make -C tests fuzzers' to build the AFL fuzzers"
@echo "macro_builder_check - check that macro_scope.hpp matches tools/macro_builder's output"
@echo "natvis - regenerate nlohmann_json.natvis from the current ABI tags and version (pass generator options via NATVIS_ARGS, see tools/generate_natvis/README.md)"
@echo "natvis - regenerate nlohmann_json.natvis from the current ABI tags and version"
@echo "pretty - beautify code with Artistic Style"
@echo "pvs_studio - run the PVS-Studio static analyzer and open the report"
@echo "release - create the release files (include.zip, json.tar.xz, single headers, signatures, hashes)"
@@ -120,15 +120,13 @@ $(AMALGAMATED_VIEW_FILE): $(SRCS)
tools/amalgamate/amalgamate.py -c tools/amalgamate/config_json_view.json -s . --verbose=yes
NATVIS_VENV=tools/generate_natvis/venv
# extra options for generate_natvis.py, e.g. NATVIS_ARGS="--abi-tags _diag,_dp,_vns --output my.natvis"
NATVIS_ARGS=
# regenerate nlohmann_json.natvis from the ABI tags and version in include/nlohmann/detail/abi_macros.hpp
# (the dependencies are installed into a virtual environment first)
natvis:
@test -d $(NATVIS_VENV) || python3 -mvenv $(NATVIS_VENV)
@$(NATVIS_VENV)/bin/python3 -c 'import jinja2' 2>/dev/null || $(NATVIS_VENV)/bin/pip3 install --quiet -r tools/generate_natvis/requirements.txt
$(NATVIS_VENV)/bin/python3 tools/generate_natvis/generate_natvis.py $(NATVIS_ARGS) .
$(NATVIS_VENV)/bin/python3 tools/generate_natvis/generate_natvis.py .
# regenerate the two tools/macro_builder blocks of $(MACRO_SCOPE_HPP) (see its README.md) and diff against the
# checked-in header; phony, because it never writes $(MACRO_SCOPE_HPP) itself
+19 -32
View File
@@ -116,7 +116,7 @@ There is also a [**docset**](https://github.com/Kapeli/Dash-User-Contributions/t
- **Constructors**: [basic_json](https://json.nlohmann.me/api/basic_json/basic_json), [array](https://json.nlohmann.me/api/basic_json/array), [binary](https://json.nlohmann.me/api/basic_json/binary), [object](https://json.nlohmann.me/api/basic_json/object)
- **Object inspection**: [type](https://json.nlohmann.me/api/basic_json/type), [operator value_t](https://json.nlohmann.me/api/basic_json/operator_value_t), [type_name](https://json.nlohmann.me/api/basic_json/type_name), [is_primitive](https://json.nlohmann.me/api/basic_json/is_primitive), [is_structured](https://json.nlohmann.me/api/basic_json/is_structured), [is_null](https://json.nlohmann.me/api/basic_json/is_null), [is_boolean](https://json.nlohmann.me/api/basic_json/is_boolean), [is_number](https://json.nlohmann.me/api/basic_json/is_number), [is_number_integer](https://json.nlohmann.me/api/basic_json/is_number_integer), [is_number_unsigned](https://json.nlohmann.me/api/basic_json/is_number_unsigned), [is_number_float](https://json.nlohmann.me/api/basic_json/is_number_float), [is_object](https://json.nlohmann.me/api/basic_json/is_object), [is_array](https://json.nlohmann.me/api/basic_json/is_array), [is_string](https://json.nlohmann.me/api/basic_json/is_string), [is_binary](https://json.nlohmann.me/api/basic_json/is_binary), [is_discarded](https://json.nlohmann.me/api/basic_json/is_discarded)
- **Value access**: [get](https://json.nlohmann.me/api/basic_json/get), [get_to](https://json.nlohmann.me/api/basic_json/get_to), [get_ptr](https://json.nlohmann.me/api/basic_json/get_ptr), [get_ref](https://json.nlohmann.me/api/basic_json/get_ref), [operator ValueType](https://json.nlohmann.me/api/basic_json/operator_ValueType), [get_binary](https://json.nlohmann.me/api/basic_json/get_binary)
- **Element access**: [at](https://json.nlohmann.me/api/basic_json/at), [operator[]](https://json.nlohmann.me/api/basic_json/operator%5B%5D/), [value](https://json.nlohmann.me/api/basic_json/value), [front](https://json.nlohmann.me/api/basic_json/front), [back](https://json.nlohmann.me/api/basic_json/back)
- **Element access**: [at](https://json.nlohmann.me/api/basic_json/at), [operator[]](https://json.nlohmann.me/api/basic_json/operator[]), [value](https://json.nlohmann.me/api/basic_json/value), [front](https://json.nlohmann.me/api/basic_json/front), [back](https://json.nlohmann.me/api/basic_json/back)
- **Lookup**: [find](https://json.nlohmann.me/api/basic_json/find), [count](https://json.nlohmann.me/api/basic_json/count), [contains](https://json.nlohmann.me/api/basic_json/contains)
- **Iterators**: [begin](https://json.nlohmann.me/api/basic_json/begin), [cbegin](https://json.nlohmann.me/api/basic_json/cbegin), [end](https://json.nlohmann.me/api/basic_json/end), [cend](https://json.nlohmann.me/api/basic_json/cend), [rbegin](https://json.nlohmann.me/api/basic_json/rbegin), [rend](https://json.nlohmann.me/api/basic_json/rend), [crbegin](https://json.nlohmann.me/api/basic_json/crbegin), [crend](https://json.nlohmann.me/api/basic_json/crend), [items](https://json.nlohmann.me/api/basic_json/items)
- **Capacity**: [empty](https://json.nlohmann.me/api/basic_json/empty), [size](https://json.nlohmann.me/api/basic_json/size), [max_size](https://json.nlohmann.me/api/basic_json/max_size)
@@ -125,7 +125,7 @@ There is also a [**docset**](https://github.com/Kapeli/Dash-User-Contributions/t
- **Serialization / Dumping**: [dump](https://json.nlohmann.me/api/basic_json/dump)
- **Deserialization / Parsing**: [parse](https://json.nlohmann.me/api/basic_json/parse), [accept](https://json.nlohmann.me/api/basic_json/accept), [sax_parse](https://json.nlohmann.me/api/basic_json/sax_parse)
- **JSON Pointer functions**: [flatten](https://json.nlohmann.me/api/basic_json/flatten), [unflatten](https://json.nlohmann.me/api/basic_json/unflatten)
- **JSON Patch functions**: [patch](https://json.nlohmann.me/api/basic_json/patch), [patch_inplace](https://json.nlohmann.me/api/basic_json/patch_inplace), [diff](https://json.nlohmann.me/api/basic_json/diff), [merge_patch](https://json.nlohmann.me/api/basic_json/merge_patch), [merge_diff](https://json.nlohmann.me/api/basic_json/merge_diff)
- **JSON Patch functions**: [patch](https://json.nlohmann.me/api/basic_json/patch), [patch_inplace](https://json.nlohmann.me/api/basic_json/patch_inplace), [diff](https://json.nlohmann.me/api/basic_json/diff), [merge_patch](https://json.nlohmann.me/api/basic_json/merge_patch)
- **Static functions**: [meta](https://json.nlohmann.me/api/basic_json/meta), [get_allocator](https://json.nlohmann.me/api/basic_json/get_allocator)
- **Binary formats**: [from_bjdata](https://json.nlohmann.me/api/basic_json/from_bjdata), [from_bon8](https://json.nlohmann.me/api/basic_json/from_bon8), [from_bson](https://json.nlohmann.me/api/basic_json/from_bson), [from_cbor](https://json.nlohmann.me/api/basic_json/from_cbor), [from_msgpack](https://json.nlohmann.me/api/basic_json/from_msgpack), [from_ubjson](https://json.nlohmann.me/api/basic_json/from_ubjson), [to_bjdata](https://json.nlohmann.me/api/basic_json/to_bjdata), [to_bon8](https://json.nlohmann.me/api/basic_json/to_bon8), [to_bson](https://json.nlohmann.me/api/basic_json/to_bson), [to_cbor](https://json.nlohmann.me/api/basic_json/to_cbor), [to_msgpack](https://json.nlohmann.me/api/basic_json/to_msgpack), [to_ubjson](https://json.nlohmann.me/api/basic_json/to_ubjson)
- **Non-member functions**: [operator<<](https://json.nlohmann.me/api/operator_ltlt/), [operator>>](https://json.nlohmann.me/api/operator_gtgt/), [to_string](https://json.nlohmann.me/api/basic_json/to_string)
@@ -151,7 +151,7 @@ The `json` class provides an API for manipulating a JSON value. To create a `jso
```cpp
#include <fstream>
#include <nlohmann/json.hpp>
using nlohmann::json;
using json = nlohmann::json;
// ...
@@ -164,7 +164,7 @@ If using modules (enabled with `NLOHMANN_JSON_BUILD_MODULES`), this example beco
import std;
import nlohmann.json;
using nlohmann::json;
using json = nlohmann::json;
// ...
@@ -360,7 +360,7 @@ std::cout << cpp_string << " == " << cpp_string2 << " == " << j_string.get<std::
std::cout << j_string << " == " << serialized_string << std::endl;
```
[`.dump()`](https://json.nlohmann.me/api/basic_json/dump/) returns the serialized JSON text, so a string value is enclosed in quotes and special characters are escaped. Use [`get<std::string>()`](https://json.nlohmann.me/api/basic_json/get/) to retrieve the originally stored string value.
[`.dump()`](https://json.nlohmann.me/api/basic_json/dump/) returns the originally stored string value.
Note the library only supports UTF-8. When you store strings with different encodings in the library, calling [`dump()`](https://json.nlohmann.me/api/basic_json/dump/) may throw an exception unless `json::error_handler_t::replace`, `json::error_handler_t::ignore`, or `json::error_handler_t::keep` are used as error handlers.
@@ -495,7 +495,7 @@ bool key(string_t& val);
bool parse_error(std::size_t position, const std::string& last_token, const detail::exception& ex);
```
The return value of each function determines whether parsing should proceed. For `parse_error`, returning `true` [recovers from the error](https://json.nlohmann.me/features/parsing/error_recovery/): the parser repairs the input and continues.
The return value of each function determines whether parsing should proceed.
To implement your own SAX handler, proceed as follows:
@@ -503,7 +503,7 @@ To implement your own SAX handler, proceed as follows:
2. Create an object of your SAX interface class, e.g. `my_sax`.
3. Call `bool json::sax_parse(input, &my_sax)`; where the first parameter can be any input like a string or an input stream and the second parameter is a pointer to your SAX interface.
Note the `sax_parse` function only returns a `bool` indicating whether the input was parsed without errors and no SAX event returned `false`. It does not return a `json` value - it is up to you to decide what to do with the SAX events. Furthermore, no exceptions are thrown in case of a parse error -- it is up to you what to do with the exception object passed to your `parse_error` implementation. Internally, the SAX interface is used for the DOM parser (class `json_sax_dom_parser`) as well as the acceptor (`json_sax_acceptor`), see file [`json_sax.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/input/json_sax.hpp).
Note the `sax_parse` function only returns a `bool` indicating the result of the last executed SAX event. It does not return a `json` value - it is up to you to decide what to do with the SAX events. Furthermore, no exceptions are thrown in case of a parse error -- it is up to you what to do with the exception object passed to your `parse_error` implementation. Internally, the SAX interface is used for the DOM parser (class `json_sax_dom_parser`) as well as the acceptor (`json_sax_acceptor`), see file [`json_sax.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/input/json_sax.hpp).
### STL-like access
@@ -687,15 +687,15 @@ json j_result = j_original.patch(j_patch);
// calculate a JSON patch from two JSON values
json::diff(j_result, j_original);
// [
// { "op": "replace", "path": "/baz", "value": ["one", "two", "three"] },
// { "op": "remove", "path": "/hello" },
// { "op":" replace", "path": "/baz", "value": ["one", "two", "three"] },
// { "op": "remove","path": "/hello" },
// { "op": "add", "path": "/foo", "value": "bar" }
// ]
```
### JSON Merge Patch
The library supports **JSON Merge Patch** ([RFC 7396](https://tools.ietf.org/html/rfc7396)) as a patch format. Instead of using JSON Pointer (see above) to specify values to be manipulated, it describes the changes using a syntax that closely mimics the document being modified.
The library supports **JSON Merge Patch** ([RFC 7386](https://tools.ietf.org/html/rfc7386)) as a patch format. Instead of using JSON Pointer (see above) to specify values to be manipulated, it describes the changes using a syntax that closely mimics the document being modified.
```cpp
// a JSON value
@@ -725,20 +725,6 @@ j_document.merge_patch(j_patch);
// }
```
Conversely, [`merge_diff`](https://json.nlohmann.me/api/basic_json/merge_diff/) creates a merge patch from two JSON values:
```cpp
// create a merge patch that turns j_original into j_document
json j_original = R"({"a": "b", "c": {"d": "e", "f": "g"}})"_json;
json::merge_diff(j_original, j_document);
// {
// "a": "z",
// "c": {
// "f": null
// }
// }
```
### Implicit conversions
Supported types can be implicitly converted to JSON values.
@@ -842,7 +828,7 @@ assert(p == p2);
To make this work with one of your types, you only need to provide two functions:
```cpp
using nlohmann::json;
using json = nlohmann::json;
namespace ns {
void to_json(json& j, const person& p) {
@@ -1257,7 +1243,7 @@ See the page [quality assurance](https://json.nlohmann.me/community/quality_assu
#include <nlohmann/json.hpp>
// for convenience
using nlohmann::json;
using json = nlohmann::json;
```
to the files you want to process JSON and set the necessary switches to enable C++11 (e.g., `-std=c++11` for GCC and Clang).
@@ -1288,9 +1274,13 @@ The package configuration file, `nlohmann_jsonConfig.cmake`, can be used either
To embed the library directly into an existing CMake project, place the entire source tree in a subdirectory and call `add_subdirectory()` in your `CMakeLists.txt` file:
```cmake
# Typically you don't care so much for a third party library's tests to be
# run from your own project's code.
set(JSON_BuildTests OFF CACHE INTERNAL "")
# If you only include this third party in PRIVATE source files, you do not
# need to install it when your main project gets installed.
set(JSON_Install OFF CACHE INTERNAL "")
# set(JSON_Install OFF CACHE INTERNAL "")
# Don't use include(nlohmann_json/CMakeLists.txt) since that carries with it
# unintended consequences that will break the build. It's generally
@@ -1305,8 +1295,8 @@ target_link_libraries(foo PRIVATE nlohmann_json::nlohmann_json)
##### Embedded (FetchContent)
Since CMake v3.14,
[FetchContent](https://cmake.org/cmake/help/v3.14/module/FetchContent.html) can
Since CMake v3.11,
[FetchContent](https://cmake.org/cmake/help/v3.11/module/FetchContent.html) can
be used to automatically download a release as a dependency at configure time.
Example:
@@ -1371,9 +1361,7 @@ Use your favorite [**package manager**](https://json.nlohmann.me/integration/pac
- <img src="https://raw.githubusercontent.com/nlohmann/json/refs/heads/develop/docs/mkdocs/docs/images/package_managers/swift.svg" height="20">&nbsp;[**Swift Package Manager**](https://json.nlohmann.me/integration/package_managers/#swift-package-manager) `nlohmann/json`
- <img src="https://raw.githubusercontent.com/nlohmann/json/refs/heads/develop/docs/mkdocs/docs/images/package_managers/nuget.svg" height="20">&nbsp;[**Nuget**](https://json.nlohmann.me/integration/package_managers/#nuget) `nlohmann.json`
- <img src="https://raw.githubusercontent.com/nlohmann/json/refs/heads/develop/docs/mkdocs/docs/images/package_managers/conda.svg" height="20">&nbsp;[**Conda**](https://json.nlohmann.me/integration/package_managers/#conda) `nlohmann_json`
- [**MSYS2**](https://json.nlohmann.me/integration/package_managers/#msys2) `mingw-w64-nlohmann-json`
- <img src="https://raw.githubusercontent.com/nlohmann/json/refs/heads/develop/docs/mkdocs/docs/images/package_managers/macports.svg" height="20">&nbsp;[**MacPorts**](https://json.nlohmann.me/integration/package_managers/#macports) `nlohmann-json`
- [**build2**](https://json.nlohmann.me/integration/package_managers/#build2) `nlohmann-json`
- <img src="https://raw.githubusercontent.com/nlohmann/json/refs/heads/develop/docs/mkdocs/docs/images/package_managers/CPM.png" height="20">&nbsp;[**cpm.cmake**](https://json.nlohmann.me/integration/package_managers/#cpmcmake) `gh:nlohmann/json`
- <img src="https://raw.githubusercontent.com/nlohmann/json/refs/heads/develop/docs/mkdocs/docs/images/package_managers/xmake.svg" height="20">&nbsp;[**xmake**](https://json.nlohmann.me/integration/package_managers/#xmake) `nlohmann_json`
@@ -1410,7 +1398,6 @@ THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR I
- The class contains parts of [Google Abseil](https://github.com/abseil/abseil-cpp) which is licensed under the [Apache 2.0 License](https://opensource.org/licenses/Apache-2.0).
- The class contains an adapted version of the Eisel-Lemire algorithm, its table of powers of five, and its digit comparison for long numbers from [fast_float](https://github.com/fastfloat/fast_float) by Daniel Lemire and contributors, which is available under the [MIT License](https://opensource.org/licenses/MIT) (used here), the Apache 2.0 License, and the Boost Software License. Copyright &copy; 2021 The fast_float authors
- The view's parser (`<nlohmann/json_view.hpp>`) contains techniques and code adapted from [yyjson](https://github.com/ibireme/yyjson) by YaoYuan, which is licensed under the [MIT License](https://opensource.org/licenses/MIT) (see above): table-driven decoding of `\u` escapes and fixed-offset unrolled checks.
- The view's parser (`<nlohmann/json_view.hpp>`) validates non-ASCII strings with the vector UTF-8 check of [simdjson](https://github.com/simdjson/simdjson) by Daniel Lemire, Geoff Langdale, John Keiser, and contributors (its "lookup4" algorithm and tables, after J. Keiser and D. Lemire, "Validating UTF-8 In Less Than One Instruction Per Byte", 2021), which is available under the [MIT License](https://opensource.org/licenses/MIT) (used here) and the Apache 2.0 License. Copyright &copy; 2018-2025 The simdjson authors
<img align="right" src="https://git.fsfe.org/reuse/reuse-ci/raw/branch/master/reuse-horizontal.png" alt="REUSE Software">
+11 -30
View File
@@ -361,10 +361,10 @@ add_custom_target(ci_test_coverage
COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_coverage32
COMMAND cd ${PROJECT_BINARY_DIR}/build_coverage32 && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
COMMAND ${LCOV_TOOL} --directory . --capture --output-file json.info --rc branch_coverage=1 --rc geninfo_unexecuted_blocks=1 --ignore-errors mismatch --ignore-errors unused --ignore-errors inconsistent
COMMAND ${LCOV_TOOL} -e json.info ${SRC_FILES} --output-file json.info.filtered --rc branch_coverage=1 --ignore-errors unused --ignore-errors inconsistent
COMMAND ${LCOV_TOOL} --directory . --capture --output-file json.info --rc branch_coverage=1 --rc geninfo_unexecuted_blocks=1 --ignore-errors mismatch --ignore-errors unused
COMMAND ${LCOV_TOOL} -e json.info ${SRC_FILES} --output-file json.info.filtered --rc branch_coverage=1 --ignore-errors unused
COMMAND ${CMAKE_SOURCE_DIR}/tests/thirdparty/imapdl/filterbr.py json.info.filtered > json.info.filtered.noexcept
COMMAND ${GENHTML_TOOL} --title "JSON for Modern C++" --legend --demangle-cpp --output-directory html --show-details --branch-coverage --ignore-errors inconsistent json.info.filtered.noexcept
COMMAND ${GENHTML_TOOL} --title "JSON for Modern C++" --legend --demangle-cpp --output-directory html --show-details --branch-coverage json.info.filtered.noexcept
COMMENT "Compile and test with coverage"
)
@@ -488,13 +488,6 @@ add_custom_target(ci_clang_analyze
# Check code with Cppcheck.
###############################################################################
# default_defines.hpp expands the Hedley macros to the compiler's feature-test operators, which Cppcheck does not know.
# Since Cppcheck 2.20, it rejects their invocations in #if conditions instead of evaluating them as 0.
file(WRITE ${CMAKE_BINARY_DIR}/cppcheck_feature_tests.hpp "")
foreach(OPERATOR __has_attribute __has_builtin __has_cpp_attribute __has_declspec_attribute __has_extension __has_feature __has_include __has_warning)
file(APPEND ${CMAKE_BINARY_DIR}/cppcheck_feature_tests.hpp "#define ${OPERATOR}(x) 0\n")
endforeach()
add_custom_target(ci_cppcheck
COMMAND mkdir -p cppcheck
COMMAND clang -dM -E -x c++ -std=c++11 ${CMAKE_SOURCE_DIR}/include/nlohmann/thirdparty/hedley/hedley.hpp > default_defines.hpp 2> /dev/null
@@ -503,7 +496,7 @@ add_custom_target(ci_cppcheck
COMMAND venv_cppcheck/bin/cppcheck --enable=warning --check-level=exhaustive --inline-suppr --inconclusive --force
--std=c++11 ${PROJECT_SOURCE_DIR}/include/nlohmann/json.hpp -I ${CMAKE_SOURCE_DIR}/include
--error-exitcode=1 --relative-paths=${PROJECT_SOURCE_DIR} -j ${N} --include=default_defines.hpp
--include=${CMAKE_BINARY_DIR}/cppcheck_feature_tests.hpp --cppcheck-build-dir=cppcheck
--cppcheck-build-dir=cppcheck
-UJSON_CATCH_USER -UJSON_TRY_USER -UJSON_ASSERT -UJSON_INTERNAL_CATCH -UJSON_THROW
-DJSON_HAS_CPP_11 -UJSON_HAS_CPP_14 -UJSON_HAS_CPP_17 -UJSON_HAS_CPP_20 -UJSON_HAS_THREE_WAY_COMPARISON
COMMENT "Check code with Cppcheck"
@@ -620,8 +613,9 @@ foreach(SRC_FILE ${SRC_FILES})
add_executable(single_${RELATIVE_SRC_FILE} EXCLUDE_FROM_ALL ${PROJECT_BINARY_DIR}/src_single/${RELATIVE_SRC_FILE}.cpp)
target_include_directories(single_${RELATIVE_SRC_FILE} PRIVATE ${PROJECT_SOURCE_DIR}/include)
target_compile_features(single_${RELATIVE_SRC_FILE} PRIVATE cxx_std_11)
if(RELATIVE_SRC_FILE STREQUAL "json")
# see below: report the diagnostics of json.hpp without --error, so they do not fail the build
if(RELATIVE_SRC_FILE STREQUAL "json" OR RELATIVE_SRC_FILE STREQUAL "json_literals")
# see below: report the diagnostics of json.hpp and json_literals.hpp without --error, so they
# do not fail the build
set_property(TARGET single_${RELATIVE_SRC_FILE} PROPERTY CXX_INCLUDE_WHAT_YOU_USE ${IWYU_TOOL} -Xiwyu --max_line_length=300)
else()
set_property(TARGET single_${RELATIVE_SRC_FILE} PROPERTY CXX_INCLUDE_WHAT_YOU_USE "${iwyu_path_and_options}")
@@ -635,31 +629,18 @@ foreach(SRC_FILE ${SRC_FILES})
# reporting its diagnostics (informational, via CXX_INCLUDE_WHAT_YOU_USE above) but exclude it
# from the hard gate below so a fresh IWYU/compiler combination does not fail this target on a
# nondeterministic suggestion for a header that already re-exports everything on purpose.
if(NOT RELATIVE_SRC_FILE STREQUAL "json")
# json_literals.hpp and json.hpp include each other on purpose (json.hpp includes it at its end
# unless JSON_NO_AUTOMATIC_UDLS is defined), and IWYU, not following the cycle, suggests replacing
# json.hpp with json_fwd.hpp although the literals need the complete basic_json; exclude it, too.
if(NOT RELATIVE_SRC_FILE STREQUAL "json" AND NOT RELATIVE_SRC_FILE STREQUAL "json_literals")
list(APPEND single_binaries_tus src_single/${RELATIVE_SRC_FILE}.cpp)
endif()
endforeach()
# The checks above look at each header on its own. Client code that includes only <nlohmann/json.hpp>
# must not be told by include analyzers to include another nlohmann header for what it uses
# (issue #5812): json.hpp marks those includes "IWYU pragma: export", and both IWYU and clang-tidy's
# misc-include-cleaner (disabled in .clang-tidy for the library itself) check these clients.
file(GLOB CONSUMER_FILES ${PROJECT_SOURCE_DIR}/tests/iwyu_consumer/*.cpp)
foreach(CONSUMER_FILE ${CONSUMER_FILES})
get_filename_component(CONSUMER_NAME "${CONSUMER_FILE}" NAME_WE)
add_executable(iwyu_consumer_${CONSUMER_NAME} EXCLUDE_FROM_ALL ${CONSUMER_FILE})
target_include_directories(iwyu_consumer_${CONSUMER_NAME} PRIVATE ${PROJECT_SOURCE_DIR}/include)
target_compile_features(iwyu_consumer_${CONSUMER_NAME} PRIVATE cxx_std_11)
list(APPEND single_binaries iwyu_consumer_${CONSUMER_NAME})
list(APPEND single_binaries_tus ${CONSUMER_FILE})
endforeach()
if(IWYU_TOOL_PY)
add_custom_target(ci_single_binaries
DEPENDS ${single_binaries}
COMMAND ${IWYU_TOOL_PY} -p ${PROJECT_BINARY_DIR} ${single_binaries_tus} -- ${iwyu_options}
COMMAND ${CLANG_TIDY_TOOL} -p ${PROJECT_BINARY_DIR} --checks=-*,misc-include-cleaner --warnings-as-errors=* ${CONSUMER_FILES}
VERBATIM
COMMENT "Check if headers are self-contained"
)
else()
+1 -1
View File
@@ -1 +1 @@
cppcheck==1.5.3
cppcheck==1.5.1
+1 -2
View File
@@ -341,14 +341,13 @@ def download(url, docs) -> str:
raise ValueError(f'not an http(s) URL: {url}')
req = urllib.request.Request(u.geturl(), headers={'User-Agent': USER_AGENT})
# (the scheme is checked above)
# nosemgrep: python.lang.security.audit.dynamic-urllib-use-detected.dynamic-urllib-use-detected
with urllib.request.urlopen(req, timeout=20) as r: # nosec B310
data = r.read()
ctype = r.headers.get_content_type()
path = urllib.parse.unquote(u.path).lstrip('/')
ext = os.path.splitext(path)[1]
if u.query or not ext or path.endswith('/'):
digest = hashlib.sha256(url.encode()).hexdigest()[:12]
digest = hashlib.sha1(url.encode(), usedforsecurity=False).hexdigest()[:12]
path = os.path.join(os.path.dirname(path), digest + CONTENT_TYPE_EXT.get(ctype, ext or '.bin'))
rel = os.path.normpath(os.path.join('assets', 'external', u.hostname, path))
out = os.path.join(docs, rel)
@@ -30,14 +30,6 @@ struct adl_serializer {
- [**from_json**](from_json.md) - convert a JSON value to any value type
- [**to_json**](to_json.md) - convert any value type to a JSON value
## See also
- [Arbitrary type conversions](../../features/arbitrary_types.md) - how to make your types convertible
- [**get**](../basic_json/get.md) / [**get_to**](../basic_json/get_to.md) - convert a JSON value to a C++ type
- [**basic_json**](../basic_json/basic_json.md) - construct a JSON value from a C++ value
- [**NLOHMANN_DEFINE_TYPE_INTRUSIVE**](../macros/nlohmann_define_type_intrusive.md) - generate the conversion functions for a type
- [Specializing enum conversion](../../features/enum_conversion.md)
## Version history
- Added in version 2.1.0.
+1 -33
View File
@@ -23,9 +23,6 @@ Checks whether the input is valid JSON.
respectively as UTF-8, UTF-16, and UTF-32. If `SentinelType` differs from `IteratorType`, it must be comparable to
the iterator type with `operator!=`.
Ill-formed UTF-16 and UTF-32 sequences are rejected: a lone surrogate, a high surrogate that is not followed by its
low surrogate, and a code point above `U+10FFFF` all make this function return `false`.
Unlike the [`parse()`](parse.md) function, this function neither throws an exception in case of invalid JSON input
(i.e., a parse error) nor creates diagnostic information.
@@ -38,12 +35,9 @@ Unlike the [`parse()`](parse.md) function, this function neither throws an excep
- a `#!c FILE` pointer (throws if null)
- a C-style array of characters
- a pointer to a null-terminated string of single byte characters (throws if null)
- a `std::string` or a `std::string_view` (C++17)
- a `std::string`
- a container `obj` for which `begin(obj)` and `end(obj)` produce a valid pair of iterators
(as found via ADL or member functions, with semantics compatible to `std::begin` and `std::end`)
- wide characters (`wchar_t`, `char16_t`, `char32_t`), which are converted to UTF-8: a wide string object
(`std::wstring`, `std::u16string`, `std::u32string`) or an array (e.g. a wide string literal); a pointer to a
null-terminated wide string (e.g. `std::u16string::c_str()`) is not supported
`IteratorType`
: a compatible iterator type, for instance.
@@ -131,21 +125,6 @@ outside of a string, invalid) byte; see the [FAQ entry](../../home/faq.md#nul-by
--8<-- "examples/accept__iterator_pair.output"
```
??? example "Example: (3) reading from UTF-16 strings"
The encoding is deduced from the character type of the input. String literals like `u"..."`, `U"..."`, and
`L"..."` work as well.
```cpp
--8<-- "examples/accept__wide_string.cpp"
```
Output:
```json
--8<-- "examples/accept__wide_string.output"
```
## See also
- [parse](parse.md) - deserialize from a compatible input
@@ -153,10 +132,6 @@ outside of a string, invalid) byte; see the [FAQ entry](../../home/faq.md#nul-by
- [operator>>](../operator_gtgt.md) - deserialize from stream
- [`JSON_STRICT_NUL_HANDLING`](../macros/json_strict_nul_handling.md) - opt in to rejecting a NUL byte in the input
instead of treating it as end of input
- [`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md) - read a `std::istream` one character
at a time
- [`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md) - read a `FILE*` with the locking stdio
functions
## Version history
@@ -168,13 +143,6 @@ outside of a string, invalid) byte; see the [FAQ entry](../../home/faq.md#nul-by
- Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
- `JSON_STRICT_NUL_HANDLING` added in version 3.13.0 to optionally reject a NUL byte in the input instead of treating
it as end of input; planned to become the default in version 4.0.0.
- Parsing from an `std::istream` scans the characters in its stream buffer in bulk in version 3.13.0
([`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md)).
- Parsing from a `FILE*` locks the file once instead of once per character in version 3.13.0
([`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md)).
- Ill-formed UTF-16 and UTF-32 input (a lone surrogate, a high surrogate that is not followed by its low surrogate, or
a code point above `U+10FFFF`) is rejected in version 3.13.0; before that, some such sequences were accepted or
ended the input silently.
!!! warning "Deprecation"
+1 -1
View File
@@ -27,7 +27,7 @@ To store objects in C++, a type is defined by the template parameters explained
### Default type
With the default values for `ArrayType` (`std::vector`) and `AllocatorType` (`std::allocator`), the default type for
With the default values for `ArrayType` (`std::vector`) and `AllocatorType` (`std::allocator`), the default value for
`array_t` is:
```cpp
+3 -2
View File
@@ -239,8 +239,9 @@ Strong exception safety: if an exception occurs, the original value stays intact
1. Added in version 1.0.0.
2. Added in version 1.0.0.
3. Added in version 3.11.0. Support for keys convertible to `std::string_view` added in version 3.13.0, consistently
across the lookup functions.
3. Added in version 3.11.0. Fixed in version 3.13.0 to consistently accept `std::string_view`-convertible keys, as
already supported by [`operator[]`](operator[].md), [`value`](value.md), [`find`](find.md), and other lookup
functions.
4. Added in version 2.0.0. Throws [`parse_error.109`](../../home/exceptions.md#jsonexceptionparse_error109) instead of
[`out_of_range.404`](../../home/exceptions.md#jsonexceptionout_of_range404) for a one-character array index that is not
a digit (e.g., `/x`) in version 3.13.0, as it already did for longer ones.
+1 -1
View File
@@ -63,4 +63,4 @@ Constant.
## Version history
- Added in version 1.0.0.
- Binary values are supported since version 3.8.0.
- Adjusted code to return reference to binary values in version 3.8.0.
+10 -20
View File
@@ -68,14 +68,6 @@ basic_json(basic_json&& other) noexcept;
`std::unordered_map`, `std::multimap`, and `std::unordered_multimap` with a `key_type` compatible to `string_t`
and a `value_type` from which a `basic_json` value can be constructed.
- **strings**: `string_t`, string literals, and all compatible string containers can be used.
!!! note "Rvalue containers are moved from"
If `val` is an rvalue of a compatible array-like or object-like container other than `array_t`/`object_t`
(e.g., `json j = std::move(vec);` or `json j(std::vector<std::string>{...});`), the elements are moved into
the JSON value instead of copied. Afterwards, the elements of the source container are in a valid but
unspecified state (**moved-from**). Keys of associative containers are `const` and therefore still copied.
Lvalues and `const` rvalues are copied, and the source is left unchanged.
- **numbers**: [`number_integer_t`](number_integer_t.md), [`number_unsigned_t`](number_unsigned_t.md),
[`number_float_t`](number_float_t.md), and all convertible number types such as `int`, `size_t`, `int64_t`, `float`
or `double` can be used.
@@ -244,9 +236,7 @@ basic_json(basic_json&& other) noexcept;
2. No-throw guarantee: this constructor never throws exceptions.
3. Depends on the called constructor. For types directly supported by the library (i.e., all types for which no
`to_json()` function was provided), a strong guarantee holds: if an exception is thrown, there are no changes to any
JSON value. **Exception:** when `val` is an rvalue array-like or object-like container, its elements are moved one
by one; if an exception is thrown in the middle of the conversion (e.g., an allocation failure), the JSON value is
unchanged, but the source container may be left partially moved-from.
JSON value.
4. Depends on the called constructor. For types directly supported by the library (i.e., all types for which no
`to_json()` function was provided), a strong guarantee holds: if an exception is thrown, there are no changes to any
JSON value.
@@ -482,15 +472,15 @@ basic_json(basic_json&& other) noexcept;
## Version history
1. Added in version 1.0.0.
2. Added in version 1.0.0.
3. Added in version 2.1.0.
4. Added in version 3.1.2. Explicit for different string types if `JSON_USE_IMPLICIT_CONVERSIONS` is `0` since
1. Since version 1.0.0.
2. Since version 1.0.0.
3. Since version 2.1.0.
4. Since version 3.2.0. Explicit for different string types if `JSON_USE_IMPLICIT_CONVERSIONS` is `0` since
version 3.13.0.
5. Added in version 1.0.0.
6. Added in version 1.0.0.
7. Added in version 1.0.0. Fixed in version 3.13.0 to also check the iterator range for binary values; before, a range
5. Since version 1.0.0.
6. Since version 1.0.0.
7. Since version 1.0.0. Fixed in version 3.13.0 to also check the iterator range for binary values; before, a range
that did not cover the whole value (such as `(end(), end())`) was accepted and the whole binary value was copied,
unlike the other primitive types.
8. Added in version 1.0.0.
9. Added in version 1.0.0.
8. Since version 1.0.0.
9. Since version 1.0.0.
+1 -1
View File
@@ -23,7 +23,7 @@ To store boolean values in C++, a type is defined by the template parameter `Bo
### Default type
With the default values for `BooleanType` (`#!cpp bool`), the default type for `boolean_t` is `#!cpp bool`.
With the default values for `BooleanType` (`#!cpp bool`), the default value for `boolean_t` is `#!cpp bool`.
### Storage
+3 -2
View File
@@ -141,8 +141,9 @@ Logarithmic in the size of the JSON object.
## Version history
1. Added in version 3.11.0.
2. Added in version 3.6.0. Extended template `KeyType` to support comparable types in version 3.11.0. Support for keys
convertible to `std::string_view` added in version 3.13.0, consistently across the lookup functions.
2. Added in version 3.6.0. Extended template `KeyType` to support comparable types in version 3.11.0. Fixed in
version 3.13.0 to consistently accept `std::string_view`-convertible keys, as already supported by
[`operator[]`](operator[].md), [`at`](at.md), [`value`](value.md), and other lookup functions.
3. Added in version 3.7.0.
4. Deleted overloads for integral key types added in version 3.13.0 to reject such calls at compile time instead of
causing undefined behavior at runtime.
+3 -2
View File
@@ -92,7 +92,8 @@ Logarithmic in the size of the JSON object.
## Version history
1. Added in version 3.11.0.
2. Added in version 1.0.0. Changed to support comparable key types in version 3.11.0. Support for keys convertible to
`std::string_view` added in version 3.13.0, consistently across the lookup functions.
2. Added in version 1.0.0. Changed parameter `key` type to `KeyType&&` in version 3.11.0. Fixed in version 3.13.0 to
consistently accept `std::string_view`-convertible keys, as already supported by [`operator[]`](operator[].md),
[`at`](at.md), [`value`](value.md), and other lookup functions.
3. Deleted overload for integral key types added in version 3.13.0 to reject such calls at compile time instead of
causing undefined behavior at runtime.
-1
View File
@@ -59,7 +59,6 @@ Currently, only `remove`, `add`, and `replace` operations are generated.
- [patch](patch.md) applies a JSON Patch
- [patch_inplace](patch_inplace.md) applies a JSON Patch in place
- [merge_patch](merge_patch.md) applies a JSON Merge Patch
- [merge_diff](merge_diff.md) creates a diff as a JSON Merge Patch
## Version history
-2
View File
@@ -91,8 +91,6 @@ Binary values are serialized as an object containing two keys:
- [to_string](to_string.md) returns a string representation of a JSON value
- [operator<<](../operator_ltlt.md) serialize to stream
- [`basic_json_view::dump`](../basic_json_view/dump.md) the corresponding function of `basic_json_view`, serializing
directly from a flat index without building a `basic_json` value
- [Serialization](../../features/serialization.md) - the serialization article
## Version history
+1 -1
View File
@@ -69,6 +69,6 @@ Logarithmic in the size of the container, O(log(`size()`)).
## Version history
- Added in version 2.0.8.
- Since version 2.0.8.
- Fixed in version 3.13.0: for [`ordered_json`](../ordered_json.md), the value could previously only be passed as an
rvalue; it can now also be passed as an lvalue or a `#!cpp const` lvalue, matching the behavior of `json`.
@@ -67,5 +67,5 @@ Amortized constant.
## Version history
- Added in version 2.0.8.
- Since version 2.0.8.
- Returns reference since 3.7.0.
+3 -2
View File
@@ -213,6 +213,7 @@ Strong exception safety: if an exception occurs, the original value stays intact
1. Added in version 1.0.0. Added support for binary types in version 3.8.0.
2. Added in version 1.0.0. Added support for binary types in version 3.8.0.
3. Added in version 1.0.0.
4. Added in version 3.11.0. Support for keys convertible to `std::string_view` added in version 3.13.0, consistently
across the lookup functions.
4. Added in version 3.11.0. Fixed in version 3.13.0 to consistently accept `std::string_view`-convertible keys, as
already supported by [`operator[]`](operator[].md), [`at`](at.md), [`value`](value.md), and other lookup
functions.
5. Added in version 1.0.0.
+1 -1
View File
@@ -84,4 +84,4 @@ constructor.
## Version history
- Added in version 3.0.0.
- Since version 3.0.0.
+4 -4
View File
@@ -93,13 +93,13 @@ Logarithmic in the size of the JSON object.
- [count](count.md) returns the number of occurrences of a key
- [contains](contains.md) checks whether a key exists
- [basic_json_view::find](../basic_json_view/find.md) - the same lookup on a zero-copy view (a duplicate key resolves
to the first member, whereas `parse()` keeps the last)
- [basic_json_view::find](../basic_json_view/find.md) - the same lookup on a zero-copy view
## Version history
1. Added in version 3.11.0.
2. Added in version 1.0.0. Changed to support comparable types in version 3.11.0. Support for keys convertible to
`std::string_view` added in version 3.13.0, consistently across the lookup functions.
2. Added in version 1.0.0. Changed to support comparable types in version 3.11.0. Fixed in version 3.13.0 to
consistently accept `std::string_view`-convertible keys, as already supported by [`operator[]`](operator[].md),
[`at`](at.md), [`value`](value.md), and other lookup functions.
3. Deleted overloads for integral key types added in version 3.13.0 to reject such calls at compile time instead of
causing undefined behavior at runtime.
+2 -3
View File
@@ -51,10 +51,9 @@ Constant.
## See also
- [back](back.md) to access the last element
- [basic_json_view::front](../basic_json_view/front.md) - the same access on a zero-copy view (document order, not
sorted; duplicate keys are visited)
- [basic_json_view::front](../basic_json_view/front.md) - the same access on a zero-copy view
## Version history
- Added in version 1.0.0.
- Binary values are supported since version 3.8.0.
- Adjusted code to return reference to binary values in version 3.8.0.
+3 -3
View File
@@ -188,6 +188,6 @@ overload (3).
## Version history
1. Added in version 2.1.0.
2. Added in version 2.1.0. Extended to work with other specializations of `basic_json` in version 3.1.2.
3. Added in version 1.0.0.
1. Since version 2.1.0.
2. Since version 2.1.0. Extended to work with other specializations of `basic_json` in version 3.2.0.
3. Since version 1.0.0.
+1 -1
View File
@@ -45,7 +45,7 @@ Constant.
#include <iostream>
#include <nlohmann/json.hpp>
using nlohmann::json;
using json = nlohmann::json;
int main()
{
+1 -1
View File
@@ -76,5 +76,5 @@ Depends on the `json_serializer<ValueType>::from_json()` implementation.
## Version history
- Added in version 3.3.0.
- Since version 3.3.0.
- Added a `static_assert` with a clear message for `const` arguments in version 3.13.0.
+1 -21
View File
@@ -44,22 +44,6 @@ are collected in [Template Parameter Requirements](../../features/types/template
- [**json**](../json.md) - default specialization
- [**ordered_json**](../ordered_json.md) - a specialization that maintains the insertion order of object keys
## Documents and views
Besides `basic_json`, the library offers a second way to hold a parsed JSON text: a
[`basic_json_document`](../basic_json_document/index.md), which owns or borrows the text and holds a flat index of the
values in it, and a [`basic_json_view`](../basic_json_view/index.md), a read-only handle to one value of such a document.
Both are defined in the header `<nlohmann/json_view.hpp>`; see
[Zero-copy JSON views](../../features/json_view.md) for the concept and the trade-offs.
- [**json_document**](../json_document.md) / [**ordered_json_document**](../ordered_json_document.md) - read-only
documents of the `basic_json` specialization they belong to
- [**json_editable_document**](../json_editable_document.md) /
[**ordered_json_editable_document**](../ordered_json_editable_document.md) - documents that can be modified in place
- [**json_view**](../json_view.md) / [**ordered_json_view**](../ordered_json_view.md) - views of a document
- [**json_editable_view**](../json_editable_view.md) /
[**ordered_json_editable_view**](../ordered_json_editable_view.md) - views of an editable document
## Iterator invalidation
All operations that add values to an **array** ([`push_back`](push_back.md) , [`operator+=`](operator+=.md),
@@ -101,7 +85,7 @@ The class satisfies the following concept requirements:
- [EqualityComparable](https://en.cppreference.com/w/cpp/named_req/EqualityComparable): JSON values can be compared with
`==`, see [`operator==`](operator_eq.md).
- [LessThanComparable](https://en.cppreference.com/w/cpp/named_req/LessThanComparable): JSON values can be compared with
`<`, see [`operator<`](operator_lt.md).
`<`, see [`operator<`](operator_le.md).
- [Swappable](https://en.cppreference.com/w/cpp/named_req/Swappable): Any JSON lvalue or rvalue of can be swapped with
any lvalue or rvalue of other compatible types, using unqualified function `swap`.
- [NullablePointer](https://en.cppreference.com/w/cpp/named_req/NullablePointer): JSON values can be compared against
@@ -301,7 +285,6 @@ Access to the JSON value
### JSON Merge Patch functions
- [**merge_patch**](merge_patch.md) - applies a JSON Merge Patch
- [**merge_diff**](merge_diff.md) (_static_) - creates a diff as a JSON Merge Patch
## Static functions
@@ -359,9 +342,6 @@ Access to the JSON value
## See also
- [RFC 8259: The JavaScript Object Notation (JSON) Data Interchange Format](https://tools.ietf.org/html/rfc8259)
- [basic_json_document](../basic_json_document/index.md) / [basic_json_view](../basic_json_view/index.md) - parse a JSON
text into a flat index and read it through a view
- [Zero-copy JSON views](../../features/json_view.md) - when to use a document and a view instead of a `basic_json`
## Version history
@@ -75,4 +75,4 @@ classDiagram
## Version history
- Added in version 3.0.0.
- Since version 3.0.0.
@@ -6,9 +6,6 @@ constexpr bool is_number_unsigned() const noexcept;
This function returns `#!cpp true` if and only if the JSON value is an unsigned integer number. This excludes
floating-point and signed integer values.
If [`number_unsigned_t`](number_unsigned_t.md) is the same type as [`number_integer_t`](number_integer_t.md), every
integer is stored as `number_integer_t`, and this function always returns `#!cpp false`.
## Return value
+3 -3
View File
@@ -100,12 +100,12 @@ When iterating over an array, `key()` will return the index of the element as st
- [begin](begin.md) returns an iterator to the first element
- [end](end.md) returns an iterator to one past the last element
- [basic_json_view::items](../basic_json_view/items.md) - the same range on a zero-copy view (`#!cpp const auto`,
not `#!cpp const auto&`: items are produced on the fly; document order, not sorted; duplicate keys are visited)
not `#!cpp const auto&`: items are produced on the fly)
## Version history
- Added in version 3.1.0 as the replacement of the static function `iterator_wrapper`, which was available since
version 1.0.0 and is deprecated since version 3.1.0.
- Added `iterator_wrapper` in version 3.0.0.
- Added `items` and deprecated `iterator_wrapper` in version 3.1.0.
- Added structured binding support in version 3.5.0.
!!! warning "Deprecation"
@@ -51,4 +51,4 @@ deserializes. See [Template Parameter Requirements](../../features/types/templat
## Version history
- Added in version 2.1.0.
- Since version 2.0.0.
@@ -1,79 +0,0 @@
# <small>nlohmann::basic_json::</small>merge_diff
```cpp
static basic_json merge_diff(const basic_json& source,
const basic_json& target);
```
Creates a [JSON Merge Patch](https://tools.ietf.org/html/rfc7396) so that value `source` can be changed into the value
`target` by calling the [`merge_patch`](merge_patch.md) function. The patch contains only what differs: changed and
added members with their new values, and removed members with the value `#!json null`. Nested objects are compared
member by member; any other value that differs, including an array, is replaced as a whole.
For two JSON values `source` and `target`, where `target` contains no object member whose value is `#!json null`, the
following code always yields `#!cpp true` (for [`ordered_json`](../ordered_json.md), see the notes below):
```cpp
basic_json patched = source;
patched.merge_patch(merge_diff(source, target));
patched == target;
```
## Parameters
`source` (in)
: JSON value to compare from
`target` (in)
: JSON value to compare against
## Return value
a JSON Merge Patch to convert the `source` to `target`
## Exception safety
Strong guarantee: `source` and `target` are never modified.
## Complexity
Linear in the total number of values (including nested ones) in `source` and `target`, times the cost of a key-based
object operation (looking up a key, or adding one to the patch): logarithmic for [`json`](../json.md), and linear for
[`ordered_json`](../ordered_json.md) (see [`ordered_map` complexity](../ordered_map.md#complexity)). For
`ordered_json`, diffing two objects with `n` and `m` members therefore takes O((n+m)²).
## Notes
- A merge patch uses `#!json null` to remove a member, so it cannot set a member to `#!json null`. As in RFC 7396, a
`#!json null` member of `target` is treated as absent: the patch removes the member from `source` instead of setting
it to `#!json null`. A member that is `#!json null` in both `source` and `target` is unchanged and left out of the
patch, so `source` keeps it.
- A merge patch cannot reorder object members, and [`merge_patch`](merge_patch.md) appends added members at the end.
For [`ordered_json`](../ordered_json.md), the patched value therefore has the same members as `target`, but not
necessarily in the same order, and may compare unequal to it. The patch lists changed and removed members in the
order of `source`, followed by added members in the order of `target`.
## Examples
??? example
The following code shows how a JSON Merge Patch is created as a diff for two JSON values.
```cpp
--8<-- "examples/merge_diff.cpp"
```
Output:
```json
--8<-- "examples/merge_diff.output"
```
## See also
- [RFC 7396 (JSON Merge Patch)](https://tools.ietf.org/html/rfc7396)
- [merge_patch](merge_patch.md) applies a JSON Merge Patch
- [diff](diff.md) creates a diff as a JSON Patch
## Version history
- Added in version 3.13.0.
@@ -67,10 +67,9 @@ returned by `#!cpp (*this)[key]`); it is read as it was when `merge_patch()` was
- [RFC 7396 (JSON Merge Patch)](https://tools.ietf.org/html/rfc7396)
- [patch](patch.md) apply a JSON patch
- [merge_diff](merge_diff.md) creates a diff as a JSON Merge Patch
## Version history
- Added in version 3.1.0.
- Added in version 3.0.0.
- Fixed use of freed or relocated memory when `apply_patch` is `#!cpp *this` or refers to a value contained in
`#!cpp *this`, in version 3.13.0.
@@ -35,7 +35,7 @@ type to use.
### Default type
With the default values for `NumberFloatType` (`double`), the default type for `number_float_t` is `#!cpp double`.
With the default values for `NumberFloatType` (`double`), the default value for `number_float_t` is `#!cpp double`.
### Default behavior
@@ -52,11 +52,9 @@ With the default values for `NumberFloatType` (`double`), the default type for `
> interoperability can be achieved by implementations that expect no more precision or range than these provide, in the
> sense that implementations will approximate JSON numbers within the expected precision.
This implementation does exactly follow this approach, as it uses double precision floating-point numbers by default.
Note that with the default `double`, numbers smaller than `-1.79769313486232e+308` or greater than
`1.79769313486232e+308` are rejected during parsing with
[`out_of_range.406`](../../home/exceptions.md#jsonexceptionout_of_range406). Non-finite values (NaN and infinity) can
only be stored by assigning them directly and are serialized to `null`.
This implementation does exactly follow this approach, as it uses double precision floating-point numbers. Note values
smaller than `-1.79769313486232e+308` and values greater than `1.79769313486232e+308` will be stored as NaN internally
and be serialized to `null`.
During deserialization (from JSON text or any of the binary formats), a finite number that does not fit into
`number_float_t` is rejected with [`out_of_range.406`](../../home/exceptions.md#jsonexceptionout_of_range406), for
@@ -31,7 +31,7 @@ to use.
### Default type
With the default values for `NumberIntegerType` (`std::int64_t`), the default type for `number_integer_t` is
With the default values for `NumberIntegerType` (`std::int64_t`), the default value for `number_integer_t` is
`#!cpp std::int64_t`.
### Default behavior
@@ -25,15 +25,14 @@ the type to use.
`NumberUnsignedType`
: the type to store unsigned integers. It must be an **unsigned integral** type (`#!cpp std::is_integral`) with a
`#!cpp std::numeric_limits` specialization, and it must be able to represent the absolute value of every
[`number_integer_t`](number_integer_t.md) value. Alternatively, it can be the same type as
[`number_integer_t`](number_integer_t.md); then every integer is stored as `number_integer_t`. See
[`number_integer_t`](number_integer_t.md) value. See
[Template Parameter Requirements](../../features/types/template_parameters.md#numberintegertype-and-numberunsignedtype).
## Notes
### Default type
With the default values for `NumberUnsignedType` (`std::uint64_t`), the default type for `number_unsigned_t` is
With the default values for `NumberUnsignedType` (`std::uint64_t`), the default value for `number_unsigned_t` is
`#!cpp std::uint64_t`.
### Default behavior
@@ -90,4 +89,3 @@ Integer number values are stored directly inside a `basic_json` type.
## Version history
- Added in version 2.0.0.
- Can be the same type as `number_integer_t` since version 3.13.0.
+1 -1
View File
@@ -36,7 +36,7 @@ To store objects in C++, a type is defined by the template parameters described
### Default type
With the default values for `ObjectType` (`std::map`), `StringType` (`std::string`), and `AllocatorType`
(`std::allocator`), the default type for `object_t` is:
(`std::allocator`), the default value for `object_t` is:
```cpp
// until C++14
@@ -128,6 +128,6 @@ interpreted as `object_t::value_type` or `std::initializer_list<basic_json>`, se
## Version history
1. Added in version 1.0.0.
2. Added in version 1.0.0.
3. Added in version 2.0.0.
1. Since version 1.0.0.
2. Since version 1.0.0.
3. Since version 2.0.0.
@@ -275,19 +275,18 @@ Strong exception safety: if an exception occurs, the original value stays intact
- documentation on [runtime assertions](../../features/assertions.md)
- see [`at`](at.md) for access by reference with range checking
- see [`value`](value.md) for access with default value
- [basic_json_view::operator[]](../basic_json_view/operator%5B%5D.md) - the same access on a zero-copy view (a duplicate
key resolves to the first member, whereas `parse()` keeps the last; a missing key gives a discarded view instead of
undefined behavior)
- [basic_json_view::operator[]](../basic_json_view/operator%5B%5D.md) - the same access on a zero-copy view (always
returns a discarded view instead of assuming undefined behavior)
## Version history
1. Added in version 1.0.0. Fixed in version 3.13.0 to throw `#!cpp std::length_error` instead of emptying the array and
accessing it out of bounds when `idx` equals the maximum value of `size_type`. A missing index in the const version
is guarded by a runtime assertion since version 3.13.0.
2. Added in version 1.0.0. Added overloads for `T* key` in version 1.1.0. The `T* key` overloads forward to
overload 3 since version 3.11.0.
3. Added in version 3.11.0. Support for keys convertible to `std::string_view` added in version 3.13.0, consistently
across the lookup functions.
2. Added in version 1.0.0. Added overloads for `T* key` in version 1.1.0. Removed overloads for `T* key` (replaced by 3)
in version 3.11.0.
3. Added in version 3.11.0. Fixed in version 3.13.0 to consistently accept `std::string_view`-convertible keys, as
already supported by [`at`](at.md), [`value`](value.md), [`find`](find.md), and other lookup functions.
4. Added in version 2.0.0. A missing array index in the const version is guarded by a runtime assertion since
version 3.13.0. Throws [`parse_error.109`](../../home/exceptions.md#jsonexceptionparse_error109) instead of
[`out_of_range.404`](../../home/exceptions.md#jsonexceptionout_of_range404) for a one-character array index that is not
@@ -89,6 +89,6 @@ Linear in the size of the JSON value.
## Version history
- Added in version 1.0.0.
- Since version 1.0.0.
- Macros `JSON_EXPLICIT`/[`JSON_USE_IMPLICIT_CONVERSIONS`](../macros/json_use_implicit_conversions.md) added
in version 3.9.0.
@@ -11,17 +11,18 @@ template<typename ScalarType>
bool operator==(ScalarType lhs, const const_reference rhs) noexcept(/* see below */); // (2)
// since C++20
bool operator==(const_reference rhs) const noexcept; // (1)
class basic_json {
bool operator==(const_reference rhs) const noexcept; // (1)
template<typename ScalarType>
bool operator==(ScalarType rhs) const noexcept(/* see below */); // (2)
template<typename ScalarType>
bool operator==(ScalarType rhs) const noexcept(/* see below */); // (2)
};
```
1. Compares two JSON values for equality according to the following rules:
- Two JSON values are equal if (1) neither value is discarded, and (2) they are of the same type and their stored
values are the same according to their respective `operator==`.
- Integer and floating-point numbers are compared by their exact values, without converting the integer to
floating-point. For instance, `9007199254740993` and `9007199254740992.0` are not equal.
- Integer and floating-point numbers are automatically converted before comparison.
2. Compares a JSON value and a scalar or a scalar and a JSON value for equality by converting the
scalar to a JSON value and comparing both JSON values according to 1.
@@ -170,8 +171,6 @@ Linear.
- [operator!=](operator_ne.md) compare for inequality
- [operator<=>](operator_spaceship.md) comparison: 3-way (C++20)
- [basic_json_view::operator==](../basic_json_view/operator_eq.md) - the same comparison on a zero-copy view, without
building a `basic_json` value for it
## Version history
@@ -15,8 +15,7 @@ bool operator<(ScalarType lhs, const const_reference rhs) noexcept(/* see below
following rules:
- If either operand is discarded, the comparison yields `#!cpp false`.
- If both operands have the same type, the values are compared using their respective `operator<`.
- Integer and floating-point numbers are compared by their exact values, without converting the integer to
floating-point. For instance, `9007199254740992.0` is less than `9007199254740993`.
- Integer and floating-point numbers are automatically converted before comparison.
- In case `lhs` and `rhs` have different types, the values are ignored and the order of the types
is considered, which is:
1. null
@@ -95,8 +95,6 @@ Linear.
- [operator==](operator_eq.md) comparison: equal
- [operator<=>](operator_spaceship.md) comparison: 3-way (C++20)
- [basic_json_view::operator!=](../basic_json_view/operator_ne.md) - the same comparison on a zero-copy view, without
building a `basic_json` value for it
## Version history
@@ -2,18 +2,22 @@
```cpp
// since C++20
std::partial_ordering operator<=>(const_reference rhs) const noexcept; // (1)
class basic_json {
std::partial_ordering operator<=>(const_reference rhs) const noexcept; // (1)
template<typename ScalarType>
std::partial_ordering operator<=>(const ScalarType rhs) const noexcept(/* see below */); // (2)
template<typename ScalarType>
std::partial_ordering operator<=>(const ScalarType rhs) const noexcept(/* see below */); // (2)
};
```
1. 3-way compares two JSON values producing a result of type `std::partial_ordering` according to the following rules:
- Two JSON values compare with a result of `std::partial_ordering::unordered` if either value is discarded.
- If both JSON values are of the same type, the result is produced by 3-way comparing their stored values using
their respective `operator<=>`.
- Integer and floating-point numbers are 3-way compared by their exact values, without converting the integer to
floating-point. For instance, `9007199254740993` compares greater than `9007199254740992.0`.
- Integer and floating-point numbers are converted to their common type and then 3-way compared using their
respective `operator<=>`.
For instance, comparing an integer and a floating-point value will 3-way compare the first value converted to
floating-point with the second value.
- Otherwise, yields a result by comparing the type (see [`value_t`](value_t.md)).
2. 3-way compares a JSON value and a scalar or a scalar and a JSON value by converting the scalar to a JSON value and
@@ -75,4 +75,4 @@ classDiagram
## Version history
- Added in version 3.0.0.
- Since version 3.0.0.
@@ -76,4 +76,4 @@ classDiagram
## Version history
- Added in version 3.0.0.
- Since version 3.0.0.
+1 -53
View File
@@ -25,10 +25,6 @@ static basic_json parse(IteratorType first, SentinelType last,
respectively as UTF-8, UTF-16, and UTF-32. If `SentinelType` differs from `IteratorType`, it must be comparable to
the iterator type with `operator!=`.
Ill-formed UTF-16 and UTF-32 sequences are rejected: a lone surrogate, a high surrogate that is not followed by its
low surrogate, and a code point above `U+10FFFF` all yield a
[`parse_error.101`](../../home/exceptions.md#jsonexceptionparse_error101).
## Template parameters
`InputType`
@@ -38,12 +34,9 @@ static basic_json parse(IteratorType first, SentinelType last,
- a `FILE` pointer (throws if null)
- a C-style array of characters
- a pointer to a null-terminated string of single byte characters (throws if null)
- a `std::string` or a `std::string_view` (C++17)
- a `std::string`
- a container `obj` for which `begin(obj)` and `end(obj)` produce a valid pair of iterators
(as found via ADL or member functions, with semantics compatible to `std::begin` and `std::end`)
- wide characters (`wchar_t`, `char16_t`, `char32_t`), which are converted to UTF-8: a wide string object
(`std::wstring`, `std::u16string`, `std::u32string`) or an array (e.g. a wide string literal); a pointer to a
null-terminated wide string (e.g. `std::u16string::c_str()`) is not supported
`IteratorType`
: a compatible iterator type, for instance.
@@ -119,23 +112,6 @@ By default, a `'\0'` (NUL) byte anywhere in the input is treated as end of input
outside of a string, invalid) byte; see the [FAQ entry](../../home/faq.md#nul-bytes-in-the-input) for details and the
[`JSON_STRICT_NUL_HANDLING`](../macros/json_strict_nul_handling.md) macro to opt into rejecting it instead.
!!! tip "Parsing into a document instead of a value"
[`basic_json_document::parse`](../basic_json_document/parse.md) accepts the same inputs and the same options, but
keeps the result as a flat index of the parsed values instead of a tree of `basic_json` values. It is faster and uses
less memory when only parts of the document are read, and it also accepts a pointer to a null-terminated wide string,
which `parse()` does not. See [Zero-copy JSON views](../../features/json_view.md).
!!! tip "Performance"
Contiguous inputs (strings, string views, vectors, arrays, pointer ranges) are the fastest to parse. A
`#!cpp std::istream` comes close: the parser scans the characters its stream buffer holds in bulk, without reading
ahead, so the stream is left exactly where it would be after reading one character at a time. A `#!cpp FILE*` is
read one character at a time, but the file is locked only once, so other threads that use the same `FILE` object
wait until parsing is done. See [input sources and performance](../../features/parsing/index.md#input-sources-and-performance),
[`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md), and
[`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md).
## Examples
??? example "Example: (1) parse from a character array"
@@ -264,22 +240,6 @@ outside of a string, invalid) byte; see the [FAQ entry](../../home/faq.md#nul-by
--8<-- "examples/trailing_commas.output"
```
??? example "Example: parse from UTF-16, UTF-32, and wide strings"
The encoding is deduced from the character type of the input; `std::u16string` and `std::u32string` are interpreted
as UTF-16 and UTF-32, and `std::wstring` uses the platform's `wchar_t` width. String literals like `u"..."`,
`U"..."`, and `L"..."` work as well, as do iterators over wide characters.
```cpp
--8<-- "examples/parse__wide_string.cpp"
```
Output:
```json
--8<-- "examples/parse__wide_string.output"
```
## See also
- [accept](accept.md) - check if the input is valid JSON
@@ -287,10 +247,6 @@ outside of a string, invalid) byte; see the [FAQ entry](../../home/faq.md#nul-by
- [operator>>](../operator_gtgt.md) - deserialize from stream
- [`JSON_STRICT_NUL_HANDLING`](../macros/json_strict_nul_handling.md) - opt in to rejecting a NUL byte in the input
instead of treating it as end of input
- [`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md) - read a `std::istream` one character
at a time
- [`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md) - read a `FILE*` with the locking stdio
functions
## Version history
@@ -305,14 +261,6 @@ outside of a string, invalid) byte; see the [FAQ entry](../../home/faq.md#nul-by
it as end of input; planned to become the default in version 4.0.0.
- Extended empty-input detection to also cover an `std::istream` without a stream buffer, and fixed a crash
(`std::terminate`) when parsing from an `std::istream` with `eofbit` in its exception mask, in version 3.13.0.
- Parsing from an `std::istream` scans the characters in its stream buffer in bulk in version 3.13.0
([`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md) restores reading one character at a
time).
- Parsing from a `FILE*` locks the file once instead of once per character in version 3.13.0
([`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md) restores `std::fgetc`).
- Ill-formed UTF-16 and UTF-32 input (a lone surrogate, a high surrogate that is not followed by its low surrogate, or
a code point above `U+10FFFF`) is rejected with `parse_error.101` in version 3.13.0; before that, some such
sequences were accepted or ended the input silently.
!!! warning "Deprecation"
@@ -84,4 +84,4 @@ or the end of file. This also holds true when reading a byte vector for binary f
## Version history
- Added in version 3.0.0.
- Since version 3.0.0.
+1 -1
View File
@@ -45,7 +45,7 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
pointer inside the patch cannot be resolved, e.g., `-` in a "remove" operation or `1a` for an array; example:
`"unresolved reference token '-'"`.
- Throws [`out_of_range.405`](../../home/exceptions.md#jsonexceptionout_of_range405) if JSON pointer has no parent
("remove", "move")
("add", "remove", "move")
- Throws [`out_of_range.411`](../../home/exceptions.md#jsonexceptionout_of_range411) if an "add" operation's target
location has a parent that is neither an object nor an array.
- Throws [`out_of_range.413`](../../home/exceptions.md#jsonexceptionout_of_range413) if a "remove" operation's target
@@ -41,7 +41,7 @@ No guarantees, value may be corrupted by an unsuccessful patch operation.
pointer inside the patch cannot be resolved, e.g., `-` in a "remove" operation or `1a` for an array; example:
`"unresolved reference token '-'"`.
- Throws [`out_of_range.405`](../../home/exceptions.md#jsonexceptionout_of_range405) if JSON pointer has no parent
("remove", "move")
("add", "remove", "move")
- Throws [`out_of_range.411`](../../home/exceptions.md#jsonexceptionout_of_range411) if an "add" operation's target
location has a parent that is neither an object nor an array.
- Throws [`out_of_range.413`](../../home/exceptions.md#jsonexceptionout_of_range413) if a "remove" operation's target
+3 -3
View File
@@ -125,6 +125,6 @@ throws.
## Version history
1. Added in version 1.0.0.
2. Added in version 1.0.0.
3. Added in version 2.0.0.
1. Since version 1.0.0.
2. Since version 1.0.0.
3. Since version 2.0.0.
+1 -27
View File
@@ -31,10 +31,6 @@ Read from input and generate SAX events
respectively as UTF-8, UTF-16, and UTF-32. If `SentinelType` differs from `IteratorType`, it must be comparable to
the iterator type with `operator!=`.
Ill-formed UTF-16 and UTF-32 sequences are rejected: a lone surrogate, a high surrogate that is not followed by its
low surrogate, and a code point above `U+10FFFF` all yield a
[`parse_error.101`](../../home/exceptions.md#jsonexceptionparse_error101).
The SAX event lister must follow the interface of [`json_sax`](../json_sax/index.md).
## Template parameters
@@ -46,12 +42,8 @@ The SAX event lister must follow the interface of [`json_sax`](../json_sax/index
- a `FILE` pointer
- a C-style array of characters
- a pointer to a null-terminated string of single byte characters
- a `std::string` or a `std::string_view` (C++17)
- a container `obj` for which `begin(obj)` and `end(obj)` produce a valid pair of iterators
(as found via ADL or member functions, with semantics compatible to `std::begin` and `std::end`)
- wide characters (`wchar_t`, `char16_t`, `char32_t`), which are converted to UTF-8: a wide string object
(`std::wstring`, `std::u16string`, `std::u32string`) or an array (e.g. a wide string literal); a pointer to a
null-terminated wide string (e.g. `std::u16string::c_str()`) is not supported
`IteratorType`
: a compatible iterator type for overload (2); a pair of character iterators whose `value_type` is an integral type
@@ -104,9 +96,7 @@ The SAX event lister must follow the interface of [`json_sax`](../json_sax/index
## Return value
`#!cpp true` if the input was parsed without errors and no SAX event returned `#!cpp false`; `#!cpp false` otherwise.
In particular, the result is `#!cpp false` for input with errors, even if the SAX parser recovered from all of them
(see [error recovery](../../features/parsing/error_recovery.md)).
return value of the last processed SAX event
## Exception safety
@@ -126,10 +116,6 @@ consumer `sax` has a super-linear complexity.
A UTF-8 byte order mark is silently ignored.
When reading from a `#!c FILE*`, the file is locked while it is parsed. The lock is recursive, so the SAX handler may
use the same file with stdio functions, but it must not wait for another thread that uses the same `FILE` object; see
[`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md).
## Examples
??? example
@@ -151,10 +137,6 @@ use the same file with stdio functions, but it must not wait for another thread
- [parse](parse.md) - deserialize from a compatible input
- [accept](accept.md) - check if the input is valid JSON
- [`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md) - read a `std::istream` one character
at a time
- [`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md) - read a `FILE*` with the locking stdio
functions
## Version history
@@ -163,17 +145,9 @@ use the same file with stdio functions, but it must not wait for another thread
- Added `ignore_trailing_commas` in version 3.13.0.
- Added `tag_handler` in version 3.13.0.
- Extended container support (1) to include types with lvalue-only ADL `begin`/`end` (matching `std::begin`/`std::end` semantics) in version 3.13.0.
- Recovering from parse errors (see [`parse_error`](../json_sax/parse_error.md)) added in version 3.13.0.
- Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
- `JSON_PRECISE_STREAM_POSITION` added in version 3.13.0 to optionally leave a `#!cpp std::istream` positioned right
after the parsed value when `strict` is `#!cpp false`.
- Parsing from an `std::istream` scans the characters in its stream buffer in bulk in version 3.13.0
([`JSON_DISABLE_STREAM_BULK_SCAN`](../macros/json_disable_stream_bulk_scan.md)).
- Parsing from a `FILE*` locks the file once instead of once per character in version 3.13.0
([`JSON_DISABLE_UNLOCKED_FILE_IO`](../macros/json_disable_unlocked_file_io.md)).
- Ill-formed UTF-16 and UTF-32 input (a lone surrogate, a high surrogate that is not followed by its low surrogate, or
a code point above `U+10FFFF`) is rejected with `parse_error.101` in version 3.13.0; before that, some such
sequences were accepted or ended the input silently.
!!! warning "Deprecation"
+1 -1
View File
@@ -32,7 +32,7 @@ JSON class into byte-sized characters during deserialization.
### Default type
With the default values for `StringType` (`std::string`), the default type for `string_t` is `#!cpp std::string`.
With the default values for `StringType` (`std::string`), the default value for `string_t` is `#!cpp std::string`.
### Encoding
+7 -7
View File
@@ -182,10 +182,10 @@ Constant.
## Version history
1. Added in version 1.0.0. Exchanges the `json_base_class_t` subobject along with the value since version 3.13.0.
2. Added in version 1.0.0. Exchanges the `json_base_class_t` subobject along with the value since version 3.13.0.
3. Added in version 1.0.0.
4. Added in version 1.0.0.
5. Added in version 1.0.0.
6. Added in version 3.8.0.
7. Added in version 3.8.0.
1. Since version 1.0.0. Exchanges the `json_base_class_t` subobject along with the value since version 3.13.0.
2. Since version 1.0.0. Exchanges the `json_base_class_t` subobject along with the value since version 3.13.0.
3. Since version 1.0.0.
4. Since version 1.0.0.
5. Since version 1.0.0.
6. Since version 3.8.0.
7. Since version 3.8.0.
+1 -1
View File
@@ -123,4 +123,4 @@ Linear in the size of the JSON value `j`.
that is not valid UTF-8 unchanged, as before; `strict` (the default if
[`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled) throws `type_error.316`.
- Throws `type_error.321` for a discarded value since version 3.13.0; previously, a discarded value nested in an
array or object was silently skipped, producing invalid BJData.
array or object was silently skipped, producing invalid BJData.
+2 -3
View File
@@ -37,9 +37,8 @@ With (2), the bytes written before the exception remain in the output adapter.
## Exceptions
- Throws [out_of_range.407](../../home/exceptions.md#jsonexceptionout_of_range407) if `j` contains an integer outside
the range of int64 (an unsigned integer above 9223372036854775807, or, with a number type wider than 64 bits, any
integer beyond int64), which BON8 cannot represent
- Throws [out_of_range.407](../../home/exceptions.md#jsonexceptionout_of_range407) if `j` contains an unsigned integer
above 9223372036854775807, which BON8 cannot represent
- Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if `j` contains a string that is not
valid UTF-8
- Throws [type_error.321](../../home/exceptions.md#jsonexceptiontype_error321) if `j` or a value nested in it is
@@ -47,10 +47,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
- Throws [`type_error.317`](../../home/exceptions.md#jsonexceptiontype_error317) if the top-level type of the JSON value
is not an object; example: `"to serialize to BSON, top-level type must be object, but is string"`
- Throws [`out_of_range.407`](../../home/exceptions.md#jsonexceptionout_of_range407) if `j` contains a signed integer
outside the range of int64 or an unsigned integer outside the range of uint64, which is only possible with a number
type wider than 64 bits; example:
`"integer number 9223372036854775808 cannot be represented by BSON as it does not fit int64"`
- Throws [`out_of_range.409`](../../home/exceptions.md#jsonexceptionout_of_range409) if a key in the JSON object contains
a null byte (code point U+0000); example: `"BSON key cannot contain code point U+0000 (at byte 2)"`
- Throws [`out_of_range.412`](../../home/exceptions.md#jsonexceptionout_of_range412) if the length of a document, array,
@@ -123,5 +119,3 @@ pass before anything is written.
that is not valid UTF-8 unchanged, as before; `strict` (the default if
[`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled) throws `type_error.316` before anything
is written.
- Throws `out_of_range.407` for integers that do not fit 64 bits since version 3.13.0; previously, integers of a
number type wider than 64 bits were silently truncated.
@@ -46,9 +46,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
## Exceptions
- Throws [`out_of_range.407`](../../home/exceptions.md#jsonexceptionout_of_range407) if `j` contains an integer
outside [-2^64, 2^64-1], which is only possible with a number type wider than 64 bits; example:
`"integer number 18446744073709551616 cannot be represented by CBOR as it does not fit [-2^64, 2^64-1]"`
- Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key in `j` is
not valid UTF-8 and `error_handler` is `strict` (the default only if
[`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled)
@@ -93,5 +90,3 @@ Linear in the size of the JSON value `j`.
[`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled) throws `type_error.316`.
- Throws `type_error.321` for a discarded value since version 3.13.0; previously, a discarded value nested in an
array or object was silently skipped, producing invalid CBOR.
- Throws `out_of_range.407` for integers that do not fit 64 bits since version 3.13.0; previously, integers of a
number type wider than 64 bits were silently truncated.
@@ -46,9 +46,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
## Exceptions
- Throws [`out_of_range.407`](../../home/exceptions.md#jsonexceptionout_of_range407) if `j` contains an integer
outside [-2^63, 2^64-1], which is only possible with a number type wider than 64 bits; example:
`"integer number 18446744073709551616 cannot be represented by MessagePack as it does not fit [-2^63, 2^64-1]"`
- Throws [`out_of_range.412`](../../home/exceptions.md#jsonexceptionout_of_range412) if the length of a string, binary
value, array, or object exceeds 4294967295, the maximum MessagePack can store; example:
`"MessagePack length 4294967296 exceeds maximum of 4294967295"`
@@ -115,5 +112,3 @@ Linear in the size of the JSON value `j`.
`number_unsigned_t`.
- Throws `type_error.321` for a discarded value since version 3.13.0; previously, a discarded value nested in an
array or object was silently skipped, producing invalid MessagePack.
- Throws `out_of_range.407` for integers that do not fit 64 bits since version 3.13.0; previously, integers of a
number type wider than 64 bits were silently truncated.
@@ -76,4 +76,4 @@ classDiagram
## Version history
- Added in version 3.0.0.
- Since version 3.0.0.
+6 -3
View File
@@ -231,8 +231,11 @@ changes to any JSON value.
1. Added in version 1.0.0. Changed parameter `default_value` type from `const ValueType&` to `ValueType&&` in version
3.11.0. Deleted overload for integral key types added in version 3.13.0 to reject such calls at compile time
instead of causing undefined behavior at runtime.
2. Added in version 3.11.0. Made `ValueType` the first template parameter in version 3.11.2. Support for keys
convertible to `std::string_view` added in version 3.13.0, consistently across the lookup functions.
3. Added in version 2.0.2. Extended to work with arrays in version 3.13.0. Throws [`parse_error.109`](../../home/exceptions.md#jsonexceptionparse_error109)
2. Added in version 3.11.0. Made `ValueType` the first template parameter in version 3.11.2. Fixed in version 3.13.0
to consistently accept `std::string_view`-convertible keys, as already supported by
[`operator[]`](operator[].md), [`at`](at.md), [`find`](find.md), and other lookup functions.
3. Added in version 2.0.2. Extended to work with arrays in version 3.13.0, including fixing an issue where resolving
`ptr` through an array unexpectedly threw `out_of_range` instead of returning the resolved element (or
`default_value`, as documented). Throws [`parse_error.109`](../../home/exceptions.md#jsonexceptionparse_error109)
instead of returning `default_value` for a one-character array index that is not a digit (e.g., `/x`) in version
3.13.0, as it already did for longer ones.
@@ -12,11 +12,6 @@ Checks whether the input is valid JSON, accepting and rejecting exactly what
function never throws an exception for invalid input, and the returned `#!cpp bool` is the only result -- no document
is returned.
The result is the same as that of `BasicJsonType::accept()` by design; the difference is how the check is made. This
function runs the document's index builder (and discards the index), while `BasicJsonType::accept()` runs the SAX
parser with a handler that ignores every event. Use this one if you go on to parse the same input with
[`parse()`](parse.md) anyway, so that both use the same code; either is fine for a plain yes/no answer.
## Template parameters
`InputType`
@@ -16,8 +16,8 @@ basic_json_document(const basic_json_document&) = delete;
2. Move constructor. Takes over `other`'s index and, if owned, its text; `other` is left as an empty document. Views
taken from `other` before the move remain valid, because the index is heap-allocated independently of the
`basic_json_document` object.
3. `basic_json_document` is move-only. Copying is disabled because of its cost: a copy would duplicate the whole
index, the decoded-string buffer, and the owned text, while a move is enough in every use we know of.
3. `basic_json_document` is move-only. Copying is disabled because it would either duplicate a potentially large index
and text, or leave two documents claiming to borrow the same buffer.
## Parameters
@@ -30,7 +30,7 @@ No-throw guarantee: the default and move constructors never throw exceptions.
## Complexity
Constant.
Constant, for the default and move constructors.
## Examples
@@ -1,129 +0,0 @@
# <small>nlohmann::basic_json_document::</small>erase
```cpp
// (1)
std::size_t erase(view_type object, string_view_t key);
// (2)
template<typename I>
void erase(view_type array, I idx);
// (3)
std::size_t erase(const json_pointer& ptr);
```
Only an **editable** document (`#!cpp Editable == true`, e.g. [`json_editable_document`](../json_editable_document.md))
has `erase`; calling it on a read-only `basic_json_document` fails to compile (`#!cpp static_assert`).
1. Removes every member of `object` whose key is `key` (see [Notes](#notes) on duplicate keys) and returns how many
were removed; `#!cpp 0` if `object` has no member with this key.
2. Removes the element at index `idx` of `array`, which must already exist (`#!cpp idx < array.size()`).
3. Removes the value the JSON pointer `ptr` refers to, relative to [`root()`](root.md). `ptr` must not be empty
([`root()`](root.md) itself cannot be erased), and the *parent* of the target must already exist. The target is
removed as in 1. if the parent is an object (returns the number of removed members, `#!cpp 0` or more) and as in 2.
if it is an array (always returns `#!cpp 1`).
## Template parameters
`I`
: an integral type other than `#!cpp bool`, deduced (overloads taking a `#!cpp bool` or a non-integral type for
`idx` do not participate in overload resolution).
## Parameters
`object` (in)
: the object to remove a member of
`array` (in)
: the array to remove an element of
`key` (in)
: the key of the member(s) to remove
`idx` (in)
: the index of the element to remove; a negative value throws (see [Exceptions](#exceptions))
`ptr` (in)
: a JSON pointer to the value to remove, relative to `root()`
## Return value
1. the number of removed members (`#!cpp 0` if `object` had none with this `key`)
2. (nothing)
3. the number of removed values (`#!cpp 0` or more for an object member, always `#!cpp 1` for an array element)
## Exceptions
1. Throws [`type_error.307`](../../home/exceptions.md#jsonexceptiontype_error307) if `object` is not an object -- the
same message [`BasicJsonType::erase`](../basic_json/erase.md) throws for the same type.
2. Throws `type_error.307` if `array` is not an array. Throws
[`out_of_range.401`](../../home/exceptions.md#jsonexceptionout_of_range401) if `idx` is negative, or if
`#!cpp idx >= array.size()`.
3. Throws [`out_of_range.405`](../../home/exceptions.md#jsonexceptionout_of_range405) ("JSON pointer has no parent")
if `ptr` is empty. Throws what [`at`](../basic_json_view/at.md) throws (overload 3) for resolving `ptr`'s parent.
For the last reference token itself: if the parent is an array, throws what 2. throws for an index that is out of
range, or, for a token that is not a valid array index,
[`parse_error.106`](../../home/exceptions.md#jsonexceptionparse_error106) (a leading `#!cpp '0'`),
[`parse_error.109`](../../home/exceptions.md#jsonexceptionparse_error109) (not a number),
[`out_of_range.410`](../../home/exceptions.md#jsonexceptionout_of_range410) (too large for `size_type`), or
[`out_of_range.404`](../../home/exceptions.md#jsonexceptionout_of_range404) (an empty token); otherwise (an
object, or a primitive value the pointer's parent resolves to) throws what 1. throws.
Overloads 1. and 2. also throw [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202)
("view does not belong to this document") if `object`/`array` is a [discarded](../basic_json_view/is_discarded.md)
view or a view of a *different* document. Overload 3. never throws `invalid_iterator.202`: it takes no view, and it
always starts from this document's own [`root()`](root.md).
## Complexity
1. Linear in the number of members of `object`.
2. Linear in the number of elements of `array` at or after `idx` (they move one slot over).
3. Linear in the number of reference tokens of `ptr` and, for each token, in the number of members of the object at
that level or the index into the array (as [`at`](../basic_json_view/at.md)), plus the complexity of 1. or 2. for
the last token.
## Notes
!!! info "Duplicate keys"
Overload 1. removes *every* member with `key`, not just the first -- unlike [`set`](set.md), which assigns the
first occurrence and drops the rest. This is why it returns a count rather than a single view: there may be
more than one member removed, or none.
Like [`set`](set.md) and [`push_back`](push_back.md), `erase` never moves an element's *value*: a view still
referring to a removed member or element keeps showing what it last held (see [Edits](index.md#edits)) -- it just no
longer appears when `array`/`object` is read, dumped, or iterated. What does change is the container's sequence of
*links* to its elements: removing an element of `array` (2.) shifts the links to the elements after it by one, as
[`insert`](insert.md) does in the other direction. *Every* iterator already taken over `array`/`object` is invalidated
by an erase, not only those at or after the removed element, since the container may now use a different sequence.
## Examples
??? example
The example below drops a deprecated field and a decommissioned entry from a configuration document -- using all
three overloads -- and shows what stays intact that would not with a plain `json`/`ordered_json` value: the order
of the fields around the ones removed, and the exact spelling of a number that was never touched.
```cpp
--8<-- "examples/basic_json_document__erase.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__erase.output"
```
## See also
- [insert](insert.md) - insert an element into an array
- [set](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers to
- [push_back](push_back.md) - append to an array
- [root](root.md) - the view of the root value, the starting point of overload 3
- [`BasicJsonType::erase`](../basic_json/erase.md) - the corresponding function of `basic_json`
- [Edits](index.md#edits) - what an edit guarantees, for every overload
## Version history
- Added in version 3.13.0.
@@ -3,27 +3,21 @@
<small>Defined in header `<nlohmann/json_view.hpp>`</small>
```cpp
template<typename BasicJsonType, bool Editable = false>
template<typename BasicJsonType>
class basic_json_document;
```
A parsed JSON text, held as a flat index of its values
([16 bytes per value](../../home/architecture.md#node-index-of-json-views)) instead of a tree of `BasicJsonType` values.
Strings and floating-point numbers stay in the source text; integers are converted while parsing, and strings that
contain escapes are decoded into one buffer owned by the document. [`basic_json_view`](../basic_json_view/index.md) is a read-only handle to one value of a
`basic_json_document`; [`materialize()`](../basic_json_view/materialize.md) turns a subtree into the
Strings and numbers stay in the source text; only strings that contain escapes are decoded, into one buffer owned by
the document. [`basic_json_view`](../basic_json_view/index.md) is a read-only handle to one value of a
`basic_json_document`; [`materialize()`](../basic_json_view/materialize.md) turns a subtree back into the
`BasicJsonType` value that [`BasicJsonType::parse()`](../basic_json/parse.md) would have produced for it.
A document may **borrow** the text it was parsed from (the caller's buffer must then outlive the document) or **own**
it (a copy, or an rvalue `#!cpp std::string` that was moved in); see [`owns_source`](owns_source.md). `basic_json_document`
is move-only: a copy would duplicate the whole index, the decoded-string buffer, and the owned text, and a move is
enough in every use we know of. The index, the decoded strings, and the owned text live in one heap block that the
document holds through a `#!cpp std::unique_ptr`; this is also why views survive a move of the document.
With `#!cpp Editable == true`, the document also offers [`set`](set.md), [`push_back`](push_back.md),
[`insert`](insert.md), and [`erase`](erase.md) to change values in place, see [Edits](#edits) below. The source text
itself is never written; a read-only document (`#!cpp Editable == false`, the default) does not carry any of the
bookkeeping edits need, and calling any of them on one fails to compile (`#!cpp static_assert`).
is move-only: copying a document would either duplicate a potentially large index and text, or leave two documents
claiming to borrow the same buffer, so it is disabled.
## Template parameters
@@ -32,38 +26,23 @@ bookkeeping edits need, and calling any of them on one fails to compile (`#!cpp
[`ordered_json`](../ordered_json.md). Only 64-bit `number_integer_t`/`number_unsigned_t` types are supported; this
is checked with a `static_assert`.
`Editable`
: whether the document supports [`set`](set.md), [`push_back`](push_back.md), [`insert`](insert.md), and
[`erase`](erase.md) (optional, `#!cpp false` by default). See [Edits](#edits) below.
## Specializations
- [**json_document**](../json_document.md) - read-only documents of the default specialization [`json`](../json.md)
- [**ordered_json_document**](../ordered_json_document.md) - read-only documents of
[`ordered_json`](../ordered_json.md)
- [**json_editable_document**](../json_editable_document.md) - editable documents of [`json`](../json.md)
- [**ordered_json_editable_document**](../ordered_json_editable_document.md) - editable documents of
[`ordered_json`](../ordered_json.md)
- [**json_document**](../json_document.md) - documents of the default specialization [`json`](../json.md)
- [**ordered_json_document**](../ordered_json_document.md) - documents of [`ordered_json`](../ordered_json.md)
## Member types
- **view_type** - the type of view returned by [`root()`](root.md) (`#!cpp basic_json_view<BasicJsonType, Editable>`)
- **view_type** - the type of view returned by [`root()`](root.md) (`#!cpp basic_json_view<BasicJsonType>`)
- **value_t** - the JSON type enumeration, see [`basic_json::value_t`](../basic_json/value_t.md)
- **image_check** - how [`load()`](load.md) validates an image (`full`, `bounds`, `none`), see [`image_check`](load.md#image_check)
## Member functions
- [(constructor)](basic_json_document.md)
### Parsing
- [**parse**](parse.md) (_static_) - deserialize from a compatible input, borrowing or owning it as appropriate
- [**parse_copy**](parse_copy.md) (_static_) - deserialize a copy of a compatible input
- [**accept**](accept.md) (_static_) - check whether the input is valid JSON
- [**read**](read.md) - (re-)parse into this document, reusing its memory
### Access
- [**root**](root.md) - the view of the root value
- [**is_discarded**](is_discarded.md) - return whether the last parse failed
- [**source**](source.md) - the parsed text
@@ -72,56 +51,6 @@ bookkeeping edits need, and calling any of them on one fails to compile (`#!cpp
- [**memory_usage**](memory_usage.md) - the number of bytes held by the document
- [**shrink_to_fit**](shrink_to_fit.md) - release unused index capacity
### Images
- [**save**](save.md) - the document as an image that `load()` reads without parsing
- [**load**](load.md) (_static_) - read an image written by `save()`
### Edits
- [**set**](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers
to (`#!cpp Editable` documents only)
- [**push_back**](push_back.md) - append to an array (`#!cpp Editable` documents only)
- [**insert**](insert.md) - insert an element into an array before a given position (`#!cpp Editable` documents only)
- [**erase**](erase.md) - remove an object member, an array element, or the value a JSON pointer refers to
(`#!cpp Editable` documents only)
## Edits
An editable document (`#!cpp Editable == true`) can be changed after parsing, with [`set`](set.md),
[`push_back`](push_back.md), [`insert`](insert.md), and [`erase`](erase.md);
[`json_editable_document`](../json_editable_document.md) and
[`ordered_json_editable_document`](../ordered_json_editable_document.md) are the corresponding specializations. A few
points apply to every edit:
- **The source text is never written**, and the parsed index never moves: every value keeps the node it was parsed
into, so [views](../basic_json_view/index.md) taken before an edit stay valid, including
[`root()`](root.md). New values (and the element sequences of an edited array/object) go to storage owned by the
document, allocated on demand.
- **A view keeps referring to the same value.** After [`set`](set.md) replaces the value a view refers to, that view
sees the new value; a view of a value that a later edit replaces or drops keeps showing what it last held. An edit
of an array or object, however, **invalidates the iterators taken over it** (its members may now live in a
different sequence), and a string obtained with [`get_string()`](../basic_json_view/get_string.md) stays valid even
as further edits happen (earlier buffers of edited text are kept alive, not overwritten).
- **Values are accepted three ways:** a [`basic_json_view`](../basic_json_view/index.md) of *any* document
(read-only or editable; it is copied, nothing is shared with the source document), a `BasicJsonType` value, or
anything `BasicJsonType` can be constructed from (numbers, strings, `#!cpp bool`, `#!cpp nullptr`, containers, ...).
- [`dump()`](../basic_json_view/dump.md) writes an edited document with members in document order, new members at
the end, and, with [`number_format::source`](../basic_json_view/number_format.md), keeps the spelling of every
number that was not itself edited -- see [Editing a document](../../features/json_view.md#editing-a-document) for
why this matters.
- [`read()`](read.md) discards all edits, [`shrink_to_fit()`](shrink_to_fit.md) does not move the node index once
there are edits, and [`memory_usage()`](memory_usage.md) includes the memory edits use.
[`source_offset()`](../basic_json_view/source_offset.md) of a value introduced by an edit is
`#!cpp static_cast<std::size_t>(-1)`, the same value it reports for a decoded string.
## See also
- [Zero-copy JSON views](../../features/json_view.md) - guide to documents and views
- [**basic_json_view**](../basic_json_view/index.md) - the non-owning handle to a value in a document
- [**json_document**](../json_document.md) and [**json_editable_document**](../json_editable_document.md) - the default specializations
- [**materialize**](../basic_json_view/materialize.md) - build a `basic_json` value from a view
## Version history
- Added in version 3.13.0.
@@ -1,114 +0,0 @@
# <small>nlohmann::basic_json_document::</small>insert
```cpp
template<typename I, typename V>
view_type insert(view_type array, I idx, V&& value);
```
Only an **editable** document (`#!cpp Editable == true`, e.g. [`json_editable_document`](../json_editable_document.md))
has `insert`; calling it on a read-only `basic_json_document` fails to compile (`#!cpp static_assert`).
Inserts `value` into `array` as a new element before position `idx`, which must not be past the end
(`#!cpp idx <= array.size()`; `#!cpp idx == array.size()` appends, like [`push_back`](push_back.md)). Unlike
[`push_back`](push_back.md), a [null](../basic_json_view/is_null.md) `array` does *not* first become an empty array:
`array` must already be an array.
`value` is accepted three ways: a [`basic_json_view`](../basic_json_view/index.md) of *any* document -- read-only or
editable, and it does not have to be `array`'s own document -- which is copied so that nothing is shared with the
source document afterward; a `BasicJsonType` value; or anything `BasicJsonType` can be constructed from (numbers,
strings, `#!cpp bool`, `#!cpp nullptr`, containers, ...).
## Template parameters
`I`
: an integral type other than `#!cpp bool`, deduced (overloads taking a `#!cpp bool` or a non-integral type for
`idx` do not participate in overload resolution).
`V`
: the type of `value`, deduced; see above for what is accepted.
## Parameters
`array` (in)
: the array to insert into
`idx` (in)
: the position to insert `value` before; a negative value throws (see [Exceptions](#exceptions))
`value` (in)
: the value to insert
## Return value
a view of the new element, now holding `value`
## Exception safety
Basic exception safety: `value` is fully encoded -- including the checks below -- into storage owned by the document
before anything already reachable from [`root()`](root.md) is touched, so a failure while encoding `value` (an
invalid argument, or `#!cpp std::bad_alloc`) leaves the document completely unchanged, other than memory allocated
for the encoding that is not reclaimed. A failure of a later allocation -- while `array` switches from its parsed
layout to a growable block, or while that block grows, see [Notes](#notes) -- can still leave `array` already
switched to that layout even though `value` itself was not inserted.
## Exceptions
Throws [`type_error.309`](../../home/exceptions.md#jsonexceptiontype_error309) if `array` is not an array -- the same
message [`BasicJsonType::insert`](../basic_json/insert.md) throws for the same type; a null `array` throws this too
(see above). Throws [`out_of_range.401`](../../home/exceptions.md#jsonexceptionout_of_range401) if `idx` is negative,
or if `#!cpp idx > array.size()`. Throws
[`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) ("view does not belong to this
document") if `array` is a [discarded](../basic_json_view/is_discarded.md) view or a view of a *different* document.
Throws [`type_error.302`](../../home/exceptions.md#jsonexceptiontype_error302) if `value` is a
[discarded](../basic_json_view/is_discarded.md) view or a [discarded](../basic_json/is_discarded.md) `BasicJsonType`
value, and [`type_error.319`](../../home/exceptions.md#jsonexceptiontype_error319) if `value` is (or contains) a
binary value -- `BasicJsonType` can hold one, but a `json_document` cannot. Throws
[`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) if `value` is (or contains) a string that is
not valid UTF-8, with the same message [`BasicJsonType::dump()`](../basic_json/dump.md) gives for that string.
## Complexity
Linear in the number of elements of `array` at or after `idx` (they move one slot over), plus time linear in the
size of `value` to encode it into the document's storage (constant for a scalar, linear in the number of nested
values for an array or object): like [`push_back`](push_back.md), the elements of `array` move to a growable block
of links the first time it is inserted into (or [`set`](set.md)/[`push_back`](push_back.md) on), and that block
grows in amortized constant time; inserting before the end within that block still shifts every later element.
## Notes
Like [`set`](set.md) on a member or an element, `insert` never moves an existing *element's value* -- only where
`array`'s *links* to its elements live -- so a view of an existing element of `array` stays valid across an
`insert`, and keeps referring to the same element even though its index shifts. Any iterator already taken over
`array` is invalidated, since it was walking the old layout. See [Edits](index.md#edits) for what stays valid across
an edit in general.
## Examples
??? example
The example below inserts a step into the middle of a deployment plan, without touching the steps that come
after it, and shows that a view taken before the insert keeps referring to the same element even though its
index shifts -- something a plain `json`/`ordered_json` array, or its `std::vector`-based storage, has no
equivalent for.
```cpp
--8<-- "examples/basic_json_document__insert.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__insert.output"
```
## See also
- [push_back](push_back.md) - append to an array
- [erase](erase.md) - remove an object member, an array element, or the value a JSON pointer refers to
- [set](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers to
- [`BasicJsonType::insert`](../basic_json/insert.md) - the corresponding function of `basic_json`
- [Edits](index.md#edits) - what an edit guarantees, for every overload
## Version history
- Added in version 3.13.0.
@@ -1,179 +0,0 @@
# <small>nlohmann::basic_json_document::</small>load
```cpp
// (1)
static basic_json_document load(const std::uint8_t* image, std::size_t size,
const image_check check = image_check::full);
// (2)
static basic_json_document load(const std::vector<std::uint8_t>& image,
const image_check check = image_check::full);
// (3)
static basic_json_document load(std::vector<std::uint8_t>&& image,
const image_check check = image_check::full);
```
1. Reads an image [`save()`](save.md) wrote, from a pointer and a byte count. The image is **borrowed**: `image`
must stay alive and unchanged for as long as the returned document, and any view taken from it, is used.
2. Reads an image from a `#!cpp std::vector`. Also **borrowed** -- equivalent to overload 1 called with
`#!cpp image.data()` and `#!cpp image.size()`.
3. Reads an image, keeping the vector instead of copying it: `image` is moved into the document (no copy), which
then owns it for as long as it needs the text and the decoded strings. [`owns_source()`](owns_source.md) is
`#!cpp true` afterward.
In every overload, the node index is copied into storage the document itself owns -- so that it is properly aligned,
and, for an [editable](index.md#edits) document, can be edited -- while the text and the decoded strings stay in
`image`. The hash indexes [large objects](../../features/json_view.md) use for lookup are rebuilt, exactly as after
parsing.
## Parameters
`image` (in)
: the image [`save()`](save.md) wrote (overloads 1 and 2), or one to take ownership of (overload 3)
`size` (in)
: the number of bytes at `image` (overload 1)
`check` (in)
: how thoroughly to validate `image` before trusting it; see [`image_check`](#image_check) below (optional,
`#!cpp image_check::full` by default)
## Return value
The document read from the image.
## Exception safety
Overloads 1 and 2 give the strong guarantee: `image` is only read, never written, so a thrown exception leaves the
caller's buffer untouched.
Overload 3 moves `image` into the document *before* validating it, so that a good image is kept without a copy. If
loading then fails, the partially built document -- and the vector now inside it -- is discarded along with the
exception, and `image` itself is left **empty**, not restored to what was passed in. Move a copy in instead, or
validate with overload 2 first, if the original vector must survive a failed load.
## Exceptions
On a big-endian target, throws [`type_error.320`](../../home/exceptions.md#jsonexceptiontype_error320) -- the same
exception [`save()`](save.md#exceptions) throws there, since the image format is little-endian only.
Otherwise throws [`parse_error.116`](../../home/exceptions.md#jsonexceptionparse_error116) if `image` is not one
`save()` could have written, or fails the requested `check`:
| message | when |
|------------------------|------------------------------------------------------------------------------------------------------|
| `too short` | `image` is `#!cpp nullptr`, or `size` is smaller than the 64-byte header |
| `unknown format` | the header's magic bytes or version do not match, or a reserved header field is not zero |
| `sizes out of range` | the node count, text size, or decoded-string size the header describes does not fit `size`, or the `#!cpp '\0'` after the text or after the decoded strings is missing |
| `the check failed` | `check` is not `#!cpp image_check::none`, and the image fails it -- see [`image_check`](#image_check) |
!!! failure "Example messages"
```
[json.exception.parse_error.116] parse error: invalid json_document image: too short
```
```
[json.exception.parse_error.116] parse error: invalid json_document image: unknown format
```
```
[json.exception.parse_error.116] parse error: invalid json_document image: sizes out of range
```
```
[json.exception.parse_error.116] parse error: invalid json_document image: the check failed
```
## Complexity
Linear in the number of nodes, which are always copied into the document. `#!cpp image_check::none` does not read
the text or the decoded strings. `#!cpp image_check::bounds` reads one byte of the text for each float token (its sign,
to check the recorded digits against the token's length), and nothing else of the text or the decoded strings.
With `#!cpp image_check::full`, linear in the size of the image (the nodes, the text, and the decoded strings), plus
sorting the ranges of the strings and of the float tokens (at most one per node): the contents of each distinct range
are checked once, however many nodes refer to it.
## Notes
### `image_check` { #image_check }
```cpp
using image_check = detail::view::image_check;
enum class image_check
{
full,
bounds,
none
};
```
How thoroughly `load()` validates `image` before trusting it.
`full` (the default)
: Checks everything the parser itself guarantees: structure and bounds; that every string is valid UTF-8 (and, for a
string still in the source text, that it contains no quote, backslash, or control character); and that every number
token is well-formed and matches the value stored for it. Strings and float tokens may share a range only if the
ranges are identical (as nodes that share a value do), and never overlap otherwise. Reading and serializing a
checked image is safe and always produces valid JSON, exactly as for a parsed document. This is the right choice for
an image from anything you do not fully control -- a file, a cache shared with other processes, a peer on the
network.
`bounds`
: Checks structure and bounds only: that every offset and count in the node index stays inside the image. So
`load()`, [`root()`](root.md), element access, and [`materialize()`](../basic_json_view/materialize.md) can never
read outside the image, even on a damaged one. It does *not* guarantee that the image describes valid JSON: a
string that a `full` check would have rejected can make [`dump()`](../basic_json_view/dump.md) write invalid UTF-8
or invalid JSON, or throw [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316), and a number can
read back with a value that does not match how it is spelled. An [editable document](../json_editable_document.md)
does not take such a string over: [`set`](set.md), [`push_back`](push_back.md) and [`insert`](insert.md) throw
`type_error.316` when they copy it from a view of the loaded document, and leave the editable document unchanged.
`bounds` skips scanning the text and the decoded strings, so it fits a cache your own process just wrote and reads
straight back, where damage would mean a bug or a hardware fault rather than adversarial input.
`none`
: Checks nothing. Reading a damaged image is undefined behavior, so use it only for an image you trust as much as
your own memory.
**Lifetime.** Overloads 1 and 2 borrow `image`: it must stay alive and byte-for-byte unchanged for as long as the
returned document, and any [view](../basic_json_view/index.md) taken from it, is used -- exactly like a document
[`parse()`](parse.md) borrowed its input for. Overload 3 avoids this by keeping the vector itself; see
[`owns_source`](owns_source.md).
!!! warning "Experimental"
The image format is versioned but not yet stable, and may change in an incompatible way before it is declared
stable; `load()` already rejects an image written by a different format version with `parse_error.116`
("unknown format"). Use images to cache a document within one build of the library, or to hand one to another
process running the *same* build on the *same* (little-endian) machine -- not as a long-term storage format.
## Examples
??? example "Caching a document, ownership, and a rejected image"
The example below saves a parsed document as an image, checks that `load()` reproduces the original
[`dump()`](../basic_json_view/dump.md) without parsing, and shows the difference between
`load(std::move(image))` (owned) and `load(image)` (borrowed). It then damages one byte of the image and shows
`image_check::full` rejecting it with `parse_error.116`, while `image_check::bounds` -- meant for a cache the
process already trusts -- still reads it without going out of bounds.
```cpp
--8<-- "examples/basic_json_document__load.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__load.output"
```
## See also
- [save](save.md) - write the document as an image
- [owns_source](owns_source.md) - return whether the document holds its own copy of the text
- [parse](parse.md) - deserialize from JSON text instead of an image
- [Images](../../features/json_view.md#images) - why and when to use images
## Version history
- Added in version 3.13.0.
@@ -4,7 +4,7 @@
bool owns_source() const noexcept;
```
Returns whether the document holds its own copy of the parsed text or is borrowing the caller's buffer.
Returns whether the document holds its own copy of the parsed text, as opposed to borrowing the caller's buffer.
## Return value
@@ -21,38 +21,32 @@ static basic_json_document parse(IteratorType first, IteratorType last,
Both overloads accept the same JSON text as [`BasicJsonType::parse()`](../basic_json/parse.md), with the same
`ignore_comments`/`ignore_trailing_commas` options, but build a [`basic_json_document`](index.md) (a flat index into
the input) instead of a tree of `BasicJsonType` values. They accept every input `BasicJsonType::parse()` takes, and in
addition a pointer to a null-terminated wide string (which `BasicJsonType::parse()` rejects). Contiguous inputs of
single-byte characters that stay alive can be borrowed; all others (streams, `#!cpp FILE*`, wide characters, which
must be converted to UTF-8, and non-contiguous iterators) are read into a copy that the document owns -- see the
Notes. Use [`parse_copy()`](parse_copy.md) to get an owned copy of a borrowable input
as well.
the input) instead of a tree of `BasicJsonType` values. The input must be byte-oriented (see the template parameters
below): not every input type of `BasicJsonType::parse()` is supported.
## Template parameters
`InputType`
: A compatible input, for instance:
: A byte-oriented input, one of:
- a `#!cpp std::string`, a `#!cpp std::string_view` (C++17), or a C-style array of single-byte characters
- a `#!cpp std::string`, `#!cpp std::string_view`, or a C-style array of single-byte characters
- a pointer to a null-terminated string of single-byte characters (`#!cpp char`, `#!cpp signed char`,
`#!cpp unsigned char`, `#!cpp std::uint8_t`)
- a container for which `#!cpp obj.data()` and `#!cpp obj.size()` give contiguous single-byte access, e.g.
`#!cpp std::vector<char>` or `#!cpp std::vector<std::uint8_t>`
- an `#!cpp std::istream` object
- a `#!cpp FILE*` pointer
- wide characters (`#!cpp wchar_t`, `#!cpp char16_t`, `#!cpp char32_t`), which are converted to UTF-8: a wide
string object (`#!cpp std::wstring`, `#!cpp std::u16string`, `#!cpp std::u32string`), an array (e.g. a wide
string literal), or a pointer to a null-terminated wide string
- a wide string object (`#!cpp std::wstring`, `#!cpp std::u16string`, `#!cpp std::u32string`), which is converted
to UTF-8
Other inputs are not supported: a `#!cpp FILE*`, and pointers to or arrays of wide characters (`#!cpp wchar_t`,
`#!cpp char16_t`, `#!cpp char32_t`) are rejected at compile time by a `#!cpp static_assert`. (Use
[`BasicJsonType::parse()`](../basic_json/parse.md) for these.)
`IteratorType`
: an input iterator type, for instance a pair of pointers such as `ptr` and `ptr + len`, or a pair of
`#!cpp std::string::iterator`; the iterators of single-byte characters are borrowed or read like the byte inputs
above, those of wide characters are converted to UTF-8
Ill-formed UTF-16 and UTF-32 sequences are rejected: a lone surrogate, a high surrogate that is not followed by its low
surrogate, and a code point above `U+10FFFF` all yield a
[`parse_error.101`](../../home/exceptions.md#jsonexceptionparse_error101).
## Parameters
`input` (in)
@@ -84,9 +78,7 @@ discarded; see [`is_discarded`](is_discarded.md).
Throws the same exception [`BasicJsonType::parse()`](../basic_json/parse.md) throws for the same input and options --
the same exception id, message, and position -- because on a failing input the library's own parser is run on the
same bytes to produce the diagnostic. This replay runs only for a failing input, and costs about a lexing pass up to
the error (its SAX handler builds no values); with `allow_exceptions` set to `#!cpp false`, it is skipped and a
discarded document is returned instead. Additionally throws
same bytes to produce the diagnostic. Additionally throws
[`out_of_range.416`](../../home/exceptions.md#jsonexceptionout_of_range416) if the input is 4294967280 bytes (4 GiB
minus 16 bytes) or larger, a size [`BasicJsonType::parse()`](../basic_json/parse.md) does not reject.
@@ -103,7 +95,7 @@ Linear in the length of the input.
| lvalue byte container (`std::string`, `std::vector<char>`, ...), `std::string_view`, C string, character array | **borrowed** -- `input` must outlive the document |
| non-const rvalue `#!cpp std::string` | **owned**, moved in without a copy |
| other rvalue byte container (including a `#!cpp const` rvalue `#!cpp std::string`) | **owned**, copied |
| stream, `#!cpp FILE*`, wide characters, or anything else read through the general input adapter | **owned**, read into a buffer (a stream is read to its end) |
| stream, wide string, or anything else read through the general input adapter | **owned**, read into a buffer (a stream is read to its end) |
For overload (2), a pair of pointers to single-byte integers (e.g. `#!cpp const char*`, `#!cpp std::uint8_t*`) is
borrowed. From C++20 on, so is any other contiguous iterator over single bytes, such as
@@ -155,11 +147,8 @@ buffer of a given length, pass a pair of pointers: `#!cpp parse(ptr, ptr + len)`
- [accept](accept.md) - check whether the input is valid JSON
- [read](read.md) - (re-)parse into this document, reusing its memory
- [owns_source](owns_source.md) - return whether the document holds its own copy of the text
- [load](load.md) - read a document from an image instead of parsing JSON text
- [`BasicJsonType::parse`](../basic_json/parse.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
- Ill-formed UTF-16 and UTF-32 input (a lone surrogate, a high surrogate that is not followed by its low surrogate, or
a code point above `U+10FFFF`) is rejected with `parse_error.101`.
@@ -1,102 +0,0 @@
# <small>nlohmann::basic_json_document::</small>push_back
```cpp
template<typename V>
view_type push_back(view_type array, V&& value);
```
Appends `value` as a new last element of `array`. A [null](../basic_json_view/is_null.md) `array` first becomes an
empty array, the same way [`set`](set.md) turns a null `object` into an empty object.
`value` is accepted three ways: a [`basic_json_view`](../basic_json_view/index.md) of *any* document -- read-only or
editable, and it does not have to be `array`'s own document -- which is copied so that nothing is shared with the
source document afterward; a `BasicJsonType` value; or anything `BasicJsonType` can be constructed from (numbers,
strings, `#!cpp bool`, `#!cpp nullptr`, containers, ...).
Only an **editable** document (`#!cpp Editable == true`, e.g. [`json_editable_document`](../json_editable_document.md))
has `push_back`; calling it on a read-only `basic_json_document` fails to compile (`#!cpp static_assert`).
## Template parameters
`V`
: the type of `value`, deduced; see above for what is accepted.
## Parameters
`array` (in)
: the array (or null value) to append to
`value` (in)
: the value to append
## Return value
a view of the new last element of `array`, now holding `value`
## Exception safety
Basic exception safety: `value` is fully encoded -- including the checks below -- into storage owned by the document
before anything already reachable from [`root()`](root.md) is touched, so a failure while encoding `value` (an
invalid argument, or `#!cpp std::bad_alloc`) leaves the document completely unchanged, other than memory allocated
for the encoding that is not reclaimed. A failure of a later allocation -- while `array` switches from its parsed
layout to a growable block, or while that block grows, see [Notes](#notes) -- can still leave a partial effect, such
as a null `array` argument already turned into an empty array even though `value` itself was not appended.
## Exceptions
Throws [`type_error.308`](../../home/exceptions.md#jsonexceptiontype_error308) if `array` is neither an array nor
null -- the same message [`BasicJsonType::push_back`](../basic_json/push_back.md) throws for the same type. Throws
[`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) ("view does not belong to this
document") if `array` is a [discarded](../basic_json_view/is_discarded.md) view or a view of a *different* document.
Throws [`type_error.302`](../../home/exceptions.md#jsonexceptiontype_error302) if `value` is a
[discarded](../basic_json_view/is_discarded.md) view or a [discarded](../basic_json/is_discarded.md) `BasicJsonType`
value, and [`type_error.319`](../../home/exceptions.md#jsonexceptiontype_error319) if `value` is (or contains) a
binary value -- `BasicJsonType` can hold one, but a `json_document` cannot. Throws
[`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) if `value` is (or contains) a string that is
not valid UTF-8, with the same message [`BasicJsonType::dump()`](../basic_json/dump.md) gives for that string.
## Complexity
Amortized constant, plus time linear in the size of `value` to encode it into the document's storage (constant for
a scalar, linear in the number of nested values for an array or object): the elements of `array` move to a growable
block of links the first time it is appended to (or [`set`](set.md) on), and that block itself grows -- doubling its
capacity, so the cost of growing it amortizes to constant per element -- only once it runs out of room. See
[Notes](#notes).
## Notes
Like [`set`](set.md) on a member or an element, `push_back` never moves an existing element itself -- only where
`array`'s *links* to its elements live -- so a view of an existing element of `array` stays valid across a
`push_back`, but any iterator already taken over `array` is invalidated, since it was walking the old layout. See
[Edits](index.md#edits) for what stays valid across an edit in general.
## Examples
??? example
The example below appends records to an array one at a time, as they might arrive from a stream of events,
without ever building a `BasicJsonType` value for the array or for the records already in it, and shows that a
view taken from an earlier `push_back` still refers to the same element once later ones have run.
```cpp
--8<-- "examples/basic_json_document__push_back.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__push_back.output"
```
## See also
- [set](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers to
- [insert](insert.md) - insert an element into an array before a given position
- [erase](erase.md) - remove an object member, an array element, or the value a JSON pointer refers to
- [root](root.md) - the view of the root value
- [`BasicJsonType::push_back`](../basic_json/push_back.md) - the corresponding function of `basic_json`
- [Edits](index.md#edits) - what an edit guarantees, for every overload
## Version history
- Added in version 3.13.0.
@@ -47,14 +47,7 @@ Every view taken from `#!cpp *this` before the call -- including the previous [`
whether or not the new parse succeeds; take fresh views from [`root()`](root.md) afterward.
`input` is borrowed or owned by the same rules as [`parse()`](parse.md#notes); a document can borrow on one call and
own on the next, since ownership is decided freshly each time. An input that is copied (see the table in
[`parse()`](parse.md#notes)) is written into the document's previous owned copy, reusing its memory; a moved-in
`#!cpp std::string` replaces it.
Reusing a document matters most for large inputs: the operating system provides the memory of a fresh node index one
page at a time, and every page costs a page fault the first time it is written. On x86-64 Linux (4 KiB pages), parsing
a 55 MB document into a reused document took about 40 % less time than parsing it into a fresh one. Programs that parse
many documents of similar size should therefore keep one document and call `read()`.
own on the next, since ownership is decided freshly each time.
An integer argument that is not a `#!cpp bool` where the flags are expected, such as `#!cpp read(ptr, len)`, does not
compile; see [`parse`](parse.md#notes).
@@ -80,7 +73,6 @@ compile; see [`parse`](parse.md#notes).
- [parse](parse.md) - deserialize from a compatible input
- [root](root.md) - the view of the root value
- [load](load.md) - read a document from an image instead of parsing JSON text
## Version history
@@ -39,8 +39,7 @@ auto v = doc.root();
`root()` is a cheap handle into the document's index, not a copy of anything; call it as often as needed. The
returned view is valid under the same conditions as any other view of the document -- see
[Object inspection](../basic_json_view/index.md) -- in particular, it is invalidated by the next
[`read()`](read.md) or [`shrink_to_fit()`](shrink_to_fit.md) on this document. A view can dangle, like a
`#!cpp std::string_view`; see [Ownership and lifetime](../../features/json_view.md#ownership-and-lifetime).
[`read()`](read.md) or [`shrink_to_fit()`](shrink_to_fit.md) on this document.
## Examples
@@ -1,104 +0,0 @@
# <small>nlohmann::basic_json_document::</small>save
```cpp
std::vector<std::uint8_t> save() const;
```
Writes the document as an *image*: a byte buffer that [`load`](load.md) reads back without parsing. The image holds
the node index, the source text (plus, for an edited document, the number tokens edits wrote), and the decoded
strings (plus the strings edits wrote) -- everything [`root()`](root.md) needs, with nothing left to parse.
An edited document is written in its *current* state, with its values in document order, the way the library's own
parser would have produced them for that JSON text: a member [`set`](set.md) added goes at the end, an
[`erase`](erase.md)d member leaves no trace, and a float that is not finite (NaN or positive/negative infinity)
becomes null, the same substitution [`dump()`](../basic_json_view/dump.md) makes. The same document always saves to
the same bytes -- also across `BasicJsonType` and `#!cpp Editable`, since the image reflects document order and
values only, not which specialization produced them.
## Return value
The image, as a `#!cpp std::vector<std::uint8_t>`. Pass it, or a pointer to its data together with its size, to
[`load`](load.md) to read the document back.
## Exception safety
Strong guarantee: `save()` does not modify `#!cpp *this` (it is `#!cpp const`), so if it throws, the document is left
exactly as it was, and the partially built image is discarded with the exception.
## Exceptions
Throws [`type_error.320`](../../home/exceptions.md#jsonexceptiontype_error320) if the document is
[discarded](is_discarded.md) -- a default-constructed document, or one a failed [`parse()`](parse.md)/
[`read()`](read.md) with `allow_exceptions == false` left discarded.
On a big-endian target, throws `type_error.320` with a different message instead: the image format is little-endian
only (see [Notes](#notes)).
Throws [`out_of_range.416`](../../home/exceptions.md#jsonexceptionout_of_range416) if the node count, the text, or
the decoded strings of the image would individually reach 4 GiB -- the same 32-bit offsets
[`parse()`](parse.md#exceptions) and, for edits, [`set`](set.md)/[`push_back`](push_back.md) are already limited to.
!!! failure "Example messages"
```
[json.exception.type_error.320] cannot save a discarded json_document
```
```
[json.exception.type_error.320] json_document images need a little-endian target
```
```
[json.exception.out_of_range.416] images of 4 GiB or more are not supported by json_document
```
## Complexity
Linear in the size of the document: the number of nodes, plus the length of the text and the decoded strings that end
up in the image.
## Notes
**Format.** The image begins with a 64-byte header (the magic bytes `#!cpp "NJVI"`, a version number, the node count,
and the sizes of the text and the decoded strings, all little-endian), followed by the nodes
([16 bytes each](../../home/architecture.md#node-index-of-json-views)), the text and a `#!cpp '\0'`, and the decoded
strings and a `#!cpp '\0'`. [`load`](load.md) checks the header, and the sizes it describes, before reading anything
else -- see [`load`'s Exceptions](load.md#exceptions).
!!! warning "Experimental"
The image format is versioned but not yet stable: it may change in an incompatible way before it is declared
stable. Use images to cache a document within one build of the library, or to hand one to another process running
the *same* build on the *same* (little-endian) machine -- not as a long-term storage format. Keep the original
JSON text if you need to read a saved document back with a future library version.
**Little-endian only.** The image is written as raw little-endian bytes, with no byte-swapping. `save()` (and
[`load`](load.md)) throw `type_error.320` on a big-endian target rather than silently produce bytes a big-endian
reader could not interpret correctly.
## Examples
??? example "Caching a parsed document as an image"
The example below saves a parsed configuration as an image -- the way a service might cache one to answer later
requests without parsing the text again -- and confirms that loading it back gives exactly the same result as
parsing did, and that saving is deterministic.
```cpp
--8<-- "examples/basic_json_document__save.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__save.output"
```
## See also
- [load](load.md) - read an image written by `save()`
- [owns_source](owns_source.md) - return whether the document holds its own copy of the text
- [`basic_json_view::dump`](../basic_json_view/dump.md) - serialize the document to JSON text instead of an image
- [Images](../../features/json_view.md#images) - why and when to use images
## Version history
- Added in version 3.13.0.
@@ -1,203 +0,0 @@
# <small>nlohmann::basic_json_document::</small>set
```cpp
// (1)
template<typename V>
view_type set(view_type target, V&& value);
// (2)
template<typename V>
view_type set(view_type object, string_view_t key, V&& value);
// (3)
template<typename I, typename V>
view_type set(view_type array, I idx, V&& value);
// (4)
template<typename V>
view_type set(const json_pointer& ptr, V&& value);
```
Only an **editable** document (`#!cpp Editable == true`, e.g. [`json_editable_document`](../json_editable_document.md))
has `set`; calling it on a read-only `basic_json_document` fails to compile (`#!cpp static_assert`).
1. Replaces the value `target` refers to with `value`.
2. Sets the member `key` of the object `object` to `value`: assigns it if `object` already has a member with this
key -- the first one, should the key occur more than once, and the later duplicates are then dropped (see the
[Notes](#notes) below) -- or appends a new member at the end otherwise. A [null](../basic_json_view/is_null.md)
`object` first becomes an empty object.
3. Assigns `value` to the element at index `idx` of the array `array`, which must already exist (`#!cpp idx <
array.size()`).
4. Sets the value the JSON pointer `ptr` refers to, relative to [`root()`](root.md), to `value`. The *parent* of the
target must already exist: an object member is set as in 2. (added if it does not exist yet), an array element is
assigned as in 3., and a last reference token of `#!cpp "-"`, or equal to the size of the array, appends `value`
instead, exactly as [`push_back`](push_back.md) would. A [null](../basic_json_view/is_null.md) parent becomes what
[`basic_json::operator[]`](../basic_json/operator%5B%5D.md) with a JSON pointer makes of it: an array if the last
reference token is `#!cpp "-"` or consists of digits only (for an index beyond 0, the array is first filled with
null values up to that index), an object otherwise. An empty `ptr` sets [`root()`](root.md) itself, as in 1.
In every overload, `value` is accepted three ways: a [`basic_json_view`](../basic_json_view/index.md) of *any*
document -- read-only or editable, and it does not have to be `target`'s/`object`'s/`array`'s own document -- which
is copied so that nothing is shared with the source document afterward; a `BasicJsonType` value; or anything
`BasicJsonType` can be constructed from (numbers, strings, `#!cpp bool`, `#!cpp nullptr`, containers, ...).
## Template parameters
`V`
: the type of `value`, deduced; see above for what is accepted.
`I`
: an integral type other than `#!cpp bool`, deduced (overloads taking a `#!cpp bool` or a non-integral type for
`idx` do not participate in overload resolution).
## Parameters
`target` (in)
: the value to replace
`object` (in)
: the object (or null value) whose member to set
`array` (in)
: the array whose element to assign
`key` (in)
: the key of the member to set
`idx` (in)
: the index of the element to assign; a negative value throws (see [Exceptions](#exceptions))
`ptr` (in)
: a JSON pointer to the value to set, relative to `root()`
`value` (in)
: the new value
## Return value
1. a view of `target`, now holding `value`
2. a view of the member `key` of `object`, now holding `value`
3. a view of the element `idx` of `array`, now holding `value`
4. a view of the value `ptr` refers to, now holding `value`
## Exception safety
Basic exception safety: `value` is fully encoded -- including the checks below -- into storage owned by the document
before anything already reachable from [`root()`](root.md) is touched, so a failure while encoding `value` (an
invalid argument, or `#!cpp std::bad_alloc`) leaves the document completely unchanged, other than memory allocated
for the encoding that is not reclaimed. A failure of a later allocation -- while an edited array or object switches
from its parsed layout to a growable block, see [Notes](#notes) -- can still leave a partial effect, such as a
[null](../basic_json_view/is_null.md) `object`/`array` argument already turned into an empty object/array even
though `value` itself was not linked in. Likewise, a failure of `value` in 4. leaves a null parent that is set with an
index beyond 0 already filled with the null values before the index.
## Exceptions
1. Throws [`type_error.302`](../../home/exceptions.md#jsonexceptiontype_error302) if `value` is a
[discarded](../basic_json_view/is_discarded.md) view, or a [discarded](../basic_json/is_discarded.md)
`BasicJsonType` value (e.g. `#!cpp BasicJsonType(value_t::discarded)`) -- an object or array `value`, of either
kind, is fine and is encoded as a whole subtree.
2. Throws [`type_error.305`](../../home/exceptions.md#jsonexceptiontype_error305) if `object` is neither an object
nor null -- the same message [`operator[]`](../basic_json_view/operator%5B%5D.md) throws for a string argument on
such a value. Throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) if `key` is not
valid UTF-8, with the same message [`BasicJsonType::dump()`](../basic_json/dump.md) gives for that string.
Also throws what 1. throws for `value`.
3. Throws `type_error.305` if `array` is not an array -- the same message `operator[]` throws for a numeric argument
on such a value. Throws [`out_of_range.401`](../../home/exceptions.md#jsonexceptionout_of_range401) if `idx` is
negative, or if `#!cpp idx >= array.size()`. Also throws what 1. throws for `value`.
4. Throws what [`at`](../basic_json_view/at.md) throws (overload 3) for resolving `ptr`'s parent, except that a
missing object member or an array index equal to the array's size at the very last reference token is not an
error there (it becomes a new member or an appended element) instead of
[`out_of_range.403`](../../home/exceptions.md#jsonexceptionout_of_range403)/[`out_of_range.402`](../../home/exceptions.md#jsonexceptionout_of_range402).
For the last reference token itself: if the parent is an object (or a primitive value, where it throws
`type_error.305`), throws what 2. throws; if the parent is an array, throws what 3. throws for an index that is
out of range, or, for a token that is not a valid array index,
[`parse_error.106`](../../home/exceptions.md#jsonexceptionparse_error106) (a leading `#!cpp '0'`),
[`parse_error.109`](../../home/exceptions.md#jsonexceptionparse_error109) (not a number),
[`out_of_range.410`](../../home/exceptions.md#jsonexceptionout_of_range410) (too large for `size_type`), or
[`out_of_range.404`](../../home/exceptions.md#jsonexceptionout_of_range404) (an empty token); the same errors are
thrown for a null parent and a token of digits (the parent is not changed then), and
[`out_of_range.401`](../../home/exceptions.md#jsonexceptionout_of_range401) if the index is 4294967295 or more.
Also throws what 1. throws for `value`.
Every overload also throws [`type_error.319`](../../home/exceptions.md#jsonexceptiontype_error319) if `value` is (or
contains) a binary value -- `BasicJsonType` can hold one, but a `json_document` cannot -- and
[`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) ("view does not belong to this
document") if `target`/`object`/`array` is a [discarded](../basic_json_view/is_discarded.md) view or a view of a
*different* document (overloads 1-3 only; overload 4 always starts from this document's own [`root()`](root.md)).
## Complexity
1. Linear in the size of `value` (encoding it into the document's storage): constant for a scalar, linear in the
number of nested values for an array or object. If `target` is itself an array or object that spans more than one
node in its parent's original, unedited layout, and `value` is a scalar, replacing it additionally costs time
linear in the size of the document, the *first* time (the parent of `target` is looked up from
[`root()`](root.md), and then switches to links) -- see [Notes](#notes). Once the parent has links, `target` is
replaced in constant time: setting every element of a large array one after the other is linear overall. To avoid
the lookup altogether, use 3. (or 2. for an object), which know the parent.
2. Linear in the number of members of `object`, to find an existing member with `key`, plus the complexity of 1. for
`value`.
3. Constant, plus the complexity of 1. for `value`.
4. Linear in the number of reference tokens of `ptr` and, for each token, in the number of members of the object at
that level or the index into the array (as [`at`](../basic_json_view/at.md)), plus the complexity of 2. or 3. for
the last token; for a null parent and an index, linear in the index.
## Notes
!!! info "Duplicate keys"
If `object` already has more than one member with `key` (2.), the *first* one is assigned `value` and every
later member with the same key is removed -- so that a lookup, an iteration, and
[`materialize()`](../basic_json_view/materialize.md) of `object` afterward all agree on a single value for
`key`, the same way [`operator[]`](../basic_json_view/operator%5B%5D.md) already picks the first occurrence of a
duplicate key for reading. See the [Notes on duplicate keys](../basic_json_view/operator%5B%5D.md#notes) of
`operator[]`.
Setting a member (2.) or an element (3., through 4.) of an array or object whose elements have not been edited
before switches it from its parsed layout to a growable block holding links to its elements; a later
[`push_back`](push_back.md) or `set` on the same container reuses that block, growing it (amortized constant time)
only once it runs out of room. This never moves an element itself -- only where the container's *links* to its
elements live -- so a view of an element stays valid, but any iterator already taken over the container is
invalidated, since it was walking the old layout. See [Edits](index.md#edits) for what stays valid across an edit in
general.
The same switch happens, for the same reason, when overload 1. replaces a multi-node array/object value with a
scalar: the *parent's* element sequence is what has to switch to links, not `target` itself, because the parent
originally stepped over `target`'s whole subtree by its node count, which no longer applies once `target` is a
one-node scalar.
## Examples
??? example "Example: (1)/(2)/(3)/(4) replace a value, set a member, assign an element, set via a JSON pointer"
The example below edits a small configuration document -- replacing a value, adding an object member, assigning
an array element, and reaching a field through a JSON pointer -- and shows what
[`dump()`](../basic_json_view/dump.md) preserves that is lost once the same edits are made on a `BasicJsonType`
value instead: the order object members were written in, and the exact spelling of a number that was never
touched.
```cpp
--8<-- "examples/basic_json_document__set.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__set.output"
```
## See also
- [push_back](push_back.md) - append to an array
- [insert](insert.md) - insert an element into an array
- [erase](erase.md) - remove an object member, an array element, or the value a JSON pointer refers to
- [root](root.md) - the view of the root value, the starting point of overload 4
- [`basic_json_view::dump`](../basic_json_view/dump.md) - serialize the document, keeping an untouched number's
spelling with `#!cpp number_format::source`
- [Edits](index.md#edits) - what an edit guarantees, for every overload
- [Editing a document](../../features/json_view.md#editing-a-document) - why editable documents keep the source
text's order and number spelling
## Version history
- Added in version 3.13.0.
+2 -5
View File
@@ -41,7 +41,7 @@ basic_json_view at(const json_pointer& ptr) const;
## Exception safety
Strong guarantee: there are no changes to the view or the document it refers to.
Strong exception safety: if an exception is thrown, there are no changes to the view or the document it refers to.
## Exceptions
@@ -77,11 +77,8 @@ None of these exceptions carry a [`JSON_DIAGNOSTICS`](../macros/json_diagnostics
1. Linear in the number of members: as for [`ordered_json`](../ordered_json.md), members are compared one after
another, in document order, stopping at the first match. Each comparison first checks the
key's length -- already known from the index, without reading the key bytes -- before comparing its content.
Objects with 128 or more members get a hash index of their keys while parsing, so that a lookup in them takes
constant time on average.
2. Linear in `idx`: elements are skipped one at a time from the first one, since they are not a fixed size in the
index (unlike `BasicJsonType`'s array, which is random-access). Constant if no element of the array is an array
or object, since the elements are then adjacent in the index.
index (unlike `BasicJsonType`'s array, which is random-access).
3. Linear in the number of reference tokens of `ptr` and, for each token, in the number of members of the object at
that level (as 1.) or the index into the array (as 2.).
+4 -4
View File
@@ -13,7 +13,7 @@ The last element or member value. For a primitive value (number, string, boolean
## Exception safety
Strong guarantee: there are no changes to the view or the document it refers to.
Strong exception safety: if an exception is thrown, there are no changes to the view or the document it refers to.
## Exceptions
@@ -28,13 +28,13 @@ This exception does not carry a [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.
Linear in the size of the array or object: unlike [`front()`](front.md), which only ever looks at the first
element, `back()` has to walk every element to find where they end, since elements are not a fixed size in the
index. Constant if no element of the array is an array or object, since the elements are then adjacent
in the index.
index.
## Notes
Unlike [`BasicJsonType::back()`](../basic_json/back.md), which has undefined behavior for an empty array or object,
`back()` throws `invalid_iterator.214` for an empty array, an empty object, a null value, or a discarded view.
`back()` throws `invalid_iterator.214` in that case -- the same way it already does for `#!json null` and for a
discarded view, where `BasicJsonType::back()` also throws.
## Examples
@@ -6,7 +6,7 @@ iterator begin() const noexcept;
Returns an iterator to the first element of an array, or the first member value of an object, in **document order**
-- the order the values appear in the source text, not sorted by key. A primitive value iterates as a range of one
element (itself), and a `#!json null` value or a [discarded](is_discarded.md) view iterates as an empty range.
element (itself); `#!json null` and a [discarded](is_discarded.md) view iterate as an empty range.
## Return value
@@ -23,7 +23,7 @@ Constant.
## Notes
For an object, iteration visits **every** member, including all occurrences of a duplicate key -- unlike
[`operator[]`](operator[].md), [`at`](at.md), [`find`](find.md), and [`contains`](contains.md),
[`operator[]`](operator[].md), [`at`](at.md), [`find`](find.md), [`contains`](contains.md), and [`count`](count.md),
which all resolve to the *first* member with a given key. See the
[Notes on duplicate keys](operator[].md#notes) of `operator[]`.
@@ -31,10 +31,6 @@ Because objects are iterated in document order rather than sorted by key, the or
iterating the [`materialize()`](materialize.md)d `BasicJsonType` value would produce: a `#!cpp basic_json` object
(`std::map`-backed by default) sorts its keys, while a view does not.
An `ordered_json` value also keeps document order, but it keeps only one entry per key: as `parse()` does, it keeps the
*last* value, at the position of the key's *first* occurrence. The view, in contrast, visits every member, including
the duplicates.
## Examples
??? example
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