Commit Graph
104 Commits
Author SHA1 Message Date
Niels Lohmann b482bd0afa Merge branch 'develop' into techdebt/5708-meta-cleanup
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 17:20:40 +02:00
Niels Lohmann c261578431 Deduplicate binary reader/writer helpers and fix stale comments (#5730)
* Fix stale and missing comments in binary_writer

The doc block of write_number() ended up above the byte_swap() helpers
added in #5286, about 80 lines from the function. It was also a plain
comment that Doxygen skips, said "write a number to output input", and
left BON8 out of the big-endian formats. Move it back onto
write_number() as a /*! block and fix the text.

write_bson() documented "@pre j.type() == value_t::object", but it
throws type_error.317 for every other type, and to_bson() relies on
that. Document the exception instead.

Explain why the CBOR binary subtype is always written with a 0xD8..0xDB
head and never in the one-byte tag form: binary_reader with
cbor_tag_handler_t::store only keeps those heads as a subtype, so
switching to write_cbor_head() would break round trips for subtypes
0..23.

Also fix the grammar of the to_char_type comment. Comments only; no
change in behavior, API or ABI.

Part of #5710

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

* Merge the duplicated UBJSON/BJData integer marker ladders

write_number_with_ubjson_prefix() (unsigned and signed overloads) and
ubjson_prefix() (number_integer and number_unsigned cases) each picked
the UBJSON/BJData integer marker (i, U, I, u, l, m, L, M, H) with their
own independent if/else ladder, and the values beyond 64 bits were
handled by a second, tag-dispatched pair of ladders. An optimized
container announces the marker of its first element via ubjson_prefix()
and then writes every element through write_number_with_ubjson_prefix(),
so the two had to be kept in lockstep by hand across four call sites.

Replace all of that with one ubjson_integer_prefix() built on
value_in_range_of<T>, and one write_ubjson_integer_payload() that
writes the value (or, for 'H', the decimal digits) for a given marker.
write_number_with_ubjson_prefix() and ubjson_prefix() keep their
signatures and now just call these two helpers.

Behavior, the public API and the ABI are unchanged. Verified with a
new regression test covering scalars and $-optimized arrays/objects at
every int8/uint8/int16/uint16/int32/uint32/int64/uint64 boundary for
to_ubjson/to_bjdata (both use_size/use_type settings), and by diffing
to_ubjson/to_bjdata output before and after over the json_test_data
corpus (bit-identical).

Part of #5710

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

* Remove dead get_char parameters in binary_reader

The non-recursive rewrite of the binary readers (#5505, #5506, #5507)
left parse_cbor_internal()'s and parse_ubjson_internal()'s get_char
parameters dead: parse_cbor_internal() has one caller and it always
passes true, and parse_ubjson_internal() has one caller and it always
uses the true default. Both parameters, and the @param docs describing
the "reuse the last character" mode they used to select, no longer
correspond to anything.

Drop both parameters, initialise fetch/prefix unconditionally, and
update the two call sites in sax_parse(). parse_cbor_value()'s and
get_ubjson_string()'s own get_char parameters are unrelated and are
left alone; both still have a false caller.

Also delete a stray `@return whether a valid MessagePack value was
passed to the SAX parser` doxygen block that sits directly above
parse_msgpack_value()'s real doc comment, a leftover of the same
rewrite.

Behavior, the public API and the ABI are unchanged; these are private
members of detail::binary_reader. Verified by compiling with
-Wunused-parameter and running unit-cbor, unit-ubjson, unit-bjdata and
unit-msgpack (offline, against the stubbed test_data.hpp).

Part of #5711

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

* Share the IEEE half-precision decoder between CBOR and BJData

binary_reader had two ~45-line copies of the IEEE 754 half-precision
decoder: CBOR's case 0xF9 and BJData's case 'h'. Once formatting is
normalised, the two blocks were identical except for the byte order
used to assemble the 16-bit half (CBOR is big endian, BJData is little
endian). Any future change to half-float decoding had to be made and
kept in sync in both places.

Add one get_half_float(format, little_endian) helper that does the two
get()/unexpect_eof() reads, assembles the half in the requested byte
order, decodes it per RFC 8949 Appendix D, and calls sax->number_float.
Both cases now just call it with their byte order; the BJData case
keeps its bjdata-only guard.

Behavior, the public API and the ABI are unchanged. Verified with a
scratch probe comparing the old and new decoders bit-for-bit (NaN by
isnan()) over all 65536 wire byte pairs, in both formats, and by
running unit-cbor and unit-bjdata (offline, against the stubbed
test_data.hpp).

Part of #5711

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

* Deduplicate the MessagePack unsigned-integer writer ladder

The number_integer (non-negative branch) and number_unsigned cases in
write_msgpack() each held their own copy of the fixint/uint8/16/32/64
ladder, kept in lockstep only by a comment ("we used the code from the
value_t::number_unsigned case here"). Both copies mixed union members:
the signed copy compared number_unsigned but wrote number_integer, and
vice versa.

Extract write_msgpack_unsigned(std::uint64_t), mirroring how
write_cbor_head() already avoids the same duplication for CBOR, and
call it from both cases. Each case now reads only its own active
union member. Output bytes are unchanged for the default 64-bit
number types.

#5710 item 3

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

* Unify float marker selection and fix the long double compile error

Four formats picked between a float32 and float64 marker through four
different helper styles: dummy-argument overloads for CBOR and
MessagePack, an std::is_same template for BON8, and a runtime if-chain
on input_format_t for write_compact_float(). With number_float_t set
to long double, to_cbor, to_msgpack and to_ubjson failed inside the
library with "call to 'get_cbor_float_prefix' is ambiguous", while
to_bson kept working because write_bson_double() takes a plain double.

Change write_compact_float() to take the two marker bytes directly
(each of its three callers already knows them at compile time) instead
of an input_format_t it only forwarded, and delete the now-unused
get_cbor_float_prefix(), get_msgpack_float_prefix(),
get_bon8_float_prefix() and get_compact_float_prefix() helpers. Turn
the two get_ubjson_float_prefix() overloads into one template. Both
write_compact_float() and get_ubjson_float_prefix() now report an
unsupported number_float_t with a static_assert naming the requirement,
rather than an ambiguous-overload error; the assert lives in the
function body, not the class scope, so to_bson with long double is
unaffected.

Verified with a probe basic_json<..., long double>: to_bson still
compiles and round-trips, while to_cbor/to_msgpack/to_ubjson now fail
to compile with the new static_assert message.

This changes the text of an existing compile error for users with an
unsupported number_float_t (documented as a public-API-visible change
in #5710).

#5710 item 1

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

* Deduplicate the BJData ndarray writer's dtype dispatch and drop <map>

write_bjdata_ndarray() built a 12-entry std::map<string_t, CharType> on
every call just to translate the _ArrayType_ name to a dtype marker
(the only reason binary_writer.hpp included <map>), then mapped dtype
to C++ type twice more: once as a switch for the range-check pass and
once as a separate if/else chain for the write pass, with nothing
checking that the two agreed. The caller also ran three at() lookups,
and the callee called value.at(key) about ten more times for the same
three members.

Replace the map with bjdata_ndarray_type_marker(), a plain string
comparison chain (a C++11 constexpr function cannot contain a switch,
so this mirrors binary_reader's own static table style). Replace the
switch/if-chain pair with one write_bjdata_ndarray_elements() that
switches on dtype once and calls a per-type helper -
write_bjdata_ndarray_element<T>() for the eight integer dtypes and
write_bjdata_ndarray_float_element() for 'd' - with a dry_run flag
selecting the range check or the actual write, so the two passes can
no longer disagree on the type. _ArrayType_, _ArraySize_ and
_ArrayData_ are now looked up once into references, and the four
header marker bytes ('[', '$', '#') are written through to_char_type()
like the rest of the UBJSON/BJData writer.

The 'd' (single-precision) rule is left exactly as before, since #5707
is expected to change it separately.

Verified byte-for-byte identical output before/after for every dtype
(including the Draft 2/Draft 3 'byte' fallback and the use_count/
use_type combinations) via a standalone probe, plus round-tripping
through from_bjdata().

Overlaps #5707, which is expected to touch the 'd' dtype case, and
#5518, which is expected to move the write_bjdata_ndarray() call site.

#5710 item 4

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

* Assert that write_bson_document() consumes every calc_bson_sizes() entry

calc_bson_sizes() and write_bson_document() are a hand-synchronized
pair of passes over the same object/array tree, introduced by #5553:
the size pass appends to nested_sizes in visiting order, and the write
pass consumes the table by position with nested_sizes[next_size++].
Nothing checked that the write pass consumed the whole table. If a
future change touched only one of the two passes - for example to skip
or reject an entry - every later size prefix in the document would be
silently wrong.

Add JSON_ASSERT(next_size == nested_sizes.size()) where
write_bson_document() returns, so such a future drift between the two
passes is caught immediately (JSON_ASSERT expands to nothing in
release builds using assert(), and the fuzzers/tests already build
with it enabled). The two passes agree today, so this changes nothing
observable; it only guards against the risk described in #5710 item 5.

Extracting a shared stepper for the two passes (the second half of the
proposed change) is left for a follow-up: it only saves ~30 lines and
the issue asks for it only if the result reads clearly, which needs
more room to get right than a mechanical cleanup pass allows.

#5710 item 5

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

* Make the BJData lookup tables static functions instead of members

binary_reader held bjd_optimized_type_markers and bjd_types_map as
non-static const members (12 string_t objects for the type-name table),
built and destroyed on every from_cbor/from_msgpack/from_bson/
from_ubjson/from_bon8/from_bjdata call even though only from_bjdata
ever reads them. They also needed the #define/decltype/#undef
workaround from #3637 and two NOLINTNEXTLINE suppressions, and
binary_writer already carries the same two lists in another form
(is_bjdata_excluded_type_marker() and a local std::map in
write_bjdata_ndarray(), the latter removed by the item-4 commit), so
the excluded-marker lists could drift apart.

Replace bjd_optimized_type_markers with static constexpr
is_bjd_excluded_optimized_type(char_int_type), using the same ||-chain
as binary_writer's is_bjdata_excluded_type_marker(). Replace
bjd_types_map with a non-constexpr static bjd_type_name(char_int_type)
switch returning nullptr for an unknown marker (a C++11 constexpr
function cannot contain a switch). Delete both
JSON_BINARY_READER_MAKE_* macros, the bjd_type pair alias, the
NOLINTNEXTLINE suppressions, detail::make_array() (no longer used
anywhere), and the now-unused <algorithm> and <array> includes.

Update the two call sites (the ND-array excluded-type check and the
_ArrayType_ lookup) accordingly, and replace unit-bjdata.cpp's
"LUT arrays are sorted" section, which only checked the two tables'
internal ordering, with a check of all 12 type names and all 8
excluded markers against both new functions.

#5711 item 1

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

* Read CBOR's 1/2/4/8-byte argument through one helper

parse_cbor_internal() hand-wrote the same "read a 1/2/4/8-byte
big-endian unsigned integer" ladder four times over:
- twice for tag numbers 0xD8-0xDB, once in the tag_handler::ignore
  branch and once, nearly identically, in the ::store branch (~90
  lines to read one integer);
- twice more for container lengths, once for array heads 0x98-0x9B and
  once for map heads 0xB8-0xBB, where the 1/2-byte forms called
  enter_array()/enter_object() directly and the 4/8-byte forms
  additionally went through get_cbor_container_size().

Add get_cbor_argument(std::uint64_t&), reading the width selected by
current & 0x1F via the same get_number() calls as before (so EOF is
reported exactly as before), and route all four sites through it:
- 0xD8-0xDB now read the argument once per branch instead of switching
  on `current` a second time; behavior split cleanly from embedded tags
  0xC0-0xD7 (tag value in the head, no argument to read), which is now
  its own case block that no longer has to fall into the ::store
  switch's "default" case to reach the same tag_pending = true; return
  true; outcome.
- 0x98-0x9B and 0xB8-0xBB collapse into one case block each, always
  going through get_cbor_container_size() (harmless for 1/2-byte
  lengths, which already always fit).

Verified byte-for-byte identical behavior before/after with a
standalone probe covering embedded and multi-byte tags under all three
tag_handler_t settings, a tag over a byte string (subtype path),
truncated tag/length arguments of every width, and array/map lengths
of every width, including the out_of_range.408 "excessive size" case:
same exceptions, same messages, same chars_read, same successful
results.

Left the string/byte-string length ladders in get_cbor_string()/
get_cbor_binary() untouched, as noted in #5711 item 2, since #5325 is
expected to touch them separately.

Overlaps #5601 (adds a branch right above the embedded-tag case) and
#5607 (touches the integer cases 0x18-0x1B, which share this ladder's
shape in separate hunks).

#5711 item 2

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

* Add leave_container() to match enter_container()

Every container is opened through enter_container(), whose docs
promise that a check placed there runs before every start event. The
close side had no equivalent: the same
"container_stack.pop_back(); dispatch to end_object() or end_array()"
sequence was written out separately in BSON, CBOR, MessagePack,
UBJSON/BJData and BON8, each copying the pattern of keeping an
is_object flag around the pop_back() that would otherwise invalidate
a reference to it. A check needed on close would have had to be added
in five places, and a sixth copy could go unnoticed.

Add leave_container() next to enter_container(), doing the same
pop-then-dispatch, and replace the five sites with it. Each site keeps
its own surrounding logic (BSON's check_bson_document_size() call
before popping, MessagePack's is_object copy used again below,
UBJSON/BJData's remaining-container handling after popping, BON8's
top used again below); only the repeated pop/dispatch line pair is
now shared.

Verified all six binary-format unit suites and unit-regression2's
deep-nesting tests (dependent count/reuse count and the bjdata ndarray
depth cases) still pass, compiled with -Wall -Wextra and ASan/UBSan.

Overlaps #5601, which is expected to add a sixth close site in its own
skip loop; that site can route through leave_container() too once it
lands.

#5711 item 4

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

* Stop passing the input format to sax_parse() when the reader already has it

binary_reader's constructor stores the format in the input_format
member, and sax_parse(format, sax_, strict, tag_handler) took the same
value again purely to dispatch on it. Every in-tree caller passed the
same value both times (all 16 from_cbor/from_msgpack/from_ubjson/
from_bjdata/from_bon8/from_bson call sites in json.hpp, and the three
public basic_json::sax_parse() overloads), so nothing was broken
today, but a caller of the detail class directly (only reachable via
JSON_PRIVATE_UNLESS_TESTED, as unit-bjdata.cpp already does) could
pass a mismatched pair - say bjdata to the constructor and ubjson to
sax_parse - and dispatch on one format while applying the other
format's rules; the default-constructed input_format_t::json reader
would additionally hit JSON_ASSERT(false) in exception_message() on
its first error.

Add sax_parse(json_sax_t*, bool, cbor_tag_handler_t) forwarding to the
existing overload with the stored input_format, and switch every
caller to it: the 16 from_*() sites (keeping their
`// cppcheck-suppress[accessMoved]` comments) and the three
basic_json::sax_parse() overloads, all of which already had the format
available from their own `format` parameter. The four-argument overload
is kept for anyone still calling it, now with
JSON_ASSERT(format == input_format) so a mismatch fails immediately
in a debug build (assert-enabled binaries, including the fuzzers and
test suite) instead of misbehaving; verified with a probe that
constructs a reader for one format and calls the explicit overload
with another, which aborts on that assertion as expected.

Removing or asserting against the constructor's input_format_t::json
default, which would affect direct detail users, is left as a separate
decision per #5711 item 5.

Overlaps #5601, which is expected to add an AllowRecovery template
parameter to sax_parse() and touch these same call sites in json.hpp.

#5711 item 5

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

* Deduplicate UBJSON/BJData signed-count handling, drop dead ndarray checks

get_ubjson_size_value()'s 'i'/'I'/'l'/'L' cases each read a differently
sized signed integer and then repeated the same "reject negative with
error 113" check; only 'L' additionally checked value_in_range_of for
the out_of_range.408 case. Any change to that error path had to be
made four times.

Add get_ubjson_signed_count<SignedType>(std::size_t&), doing the read,
the negative check and the range check once, and route all four
markers through it. The range check is a no-op for 'i'/'I'/'l' (their
values always fit std::size_t) and only live for 'L' on a 32-bit
std::size_t target, matching today's behavior exactly.

In the ndarray dimension-product loop, the preceding loop already
returns early on any zero dimension and result starts at 1, so `i > 0`
in the pre-multiplication overflow check was always true, and
`result == 0` in the post-multiplication check could not be reached
either: two positive factors whose product does not overflow (as the
pre-check already guarantees) cannot be zero. Drop the dead `i > 0 &&`
and narrow the post-check to `result == npos`, the one case the
pre-check cannot rule out (an exact, non-overflowing match with the
sentinel reserved for unknown-size containers), with a comment
explaining why.

Verified byte-for-byte identical behavior before/after with a
standalone probe covering negative counts for every marker, a matching
positive count, and ndarray inputs, plus the full unit-ubjson and
unit-bjdata suites (same assertion counts as before this change).

Overlaps #5601 (rewrites the four parse_error calls and the overflow
checks touched here) and #5607/#5707 (touch neighboring lines in the
same functions).

#5711 item 6

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

* Drop redundant format parameter and dummy float argument (review)

binary_reader::sax_parse(format, ...) only ever had to equal the format
given to the constructor, which it asserted. With every caller already
on the format-less overload, remove the four-argument overload and
dispatch on the stored input_format directly. binary_reader is a
detail class, so this is not a public API change.

get_ubjson_float_prefix() took a value only to deduce its type; make
the type an explicit template argument instead.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 22:48:32 +02:00
Niels Lohmann 3b6ae43c53 Add JSON_DISABLE_TUPLE_REFERENCE_CONVERSION to fix std::tuple conversions (#5598)
* Add JSON_DISABLE_TUPLE_REFERENCE_CONVERSION to fix std::tuple conversions

basic_json can be constructed from std::tuple<json&>, which it turns into
a one-element array. Because of this, std::tuple picks its converting
constructor that converts the whole source tuple instead of the
element-wise one. As a result, std::tuple<const json&> built from
std::forward_as_tuple(j) binds to a temporary (a compile error with libc++,
a dangling reference with other standard libraries), and std::tuple<json>
built the same way holds [j] instead of a copy of j.

The new opt-in macro JSON_DISABLE_TUPLE_REFERENCE_CONVERSION (CMake option
JSON_DisableTupleReferenceConversion) removes the conversion from a
one-element tuple holding a reference to the same basic_json type, so
std::tuple converts element-wise. It is off by default, so existing
behavior is unchanged. It does not change any function body and therefore
is not part of the ABI tag.

Fixes #2226

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

* Convert one-element tuples to arrays on every compiler

to_json for std::tuple assigns a braced list, j = { std::get<Idx>(t)... }.
With a single element that is itself a basic_json, Apple clang 15 and 16
treat j = {x} as a copy of x, so std::tuple<json>{true} became true
instead of [true]. The macOS jobs (Xcode 15.1, 16.1) failed the new
checks in unit-disable-tuple-reference-conversion and unit-regression2.

The one-element overload that already handles
JSON_BRACE_INIT_COPY_SEMANTICS builds the array (or object, for a
[string, value] element) explicitly, the same way the initializer-list
constructor does. Use it unconditionally. The output is unchanged on
compilers that already wrapped the element.

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

* Skip json reference tuple tests on clang < 4 and GCC < 5

ci_test_compilers_gcc_old (4.8) and ci_test_compilers_clang (3.4) could
not compile the new tuple tests. Creating a std::tuple of basic_json
references, e.g. std::forward_as_tuple(j), makes these compilers
instantiate basic_json's conversion operator for libstdc++'s internal
tuple bases, which fails hard. This happens with and without
JSON_DISABLE_TUPLE_REFERENCE_CONVERSION, so it is a limitation of these
compilers, not of the new option.

Tested with the CI images: clang 3.4 to 3.9 and GCC 4.8 and 4.9 fail,
clang 4, 5, and 6 and GCC 5 and 6 compile all cases. Skip only the
checks that create such tuples; the is_constructible checks still run.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 20:53:56 +02:00
Niels Lohmann 5fc53e3e0a Merge branch 'develop' into techdebt/5708-meta-cleanup
Conflicts:
- include/nlohmann/detail/conversions/from_json.hpp: kept the shared from_json_pair_array_to_map() body; develop's #5681 element-path fix (&p instead of &j) is already applied there
- include/nlohmann/detail/json_pointer.hpp: kept the parse_array_index()-based contains(); it already returns false for an empty token (#5614) and only uses documented StringType members (#5692)
- include/nlohmann/detail/macro_scope.hpp: combined develop's #5698 NLOHMANN_JSON_SERIALIZE_ENUM_STRICT message with the ::nlohmann::detail::templated_json_throw qualification
- single_include/nlohmann/json.hpp: regenerated with make amalgamate

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 20:30:46 +02:00
Niels Lohmann 6d7845d207 Fix deprecated json_pointer/string operator== warning in value() (#5683)
value(KeyType&&, default) is constrained on is_comparable_with_object_key,
which passes KeyType as a reference. is_comparable's dispatch on
is_json_pointer_of<A, B> only matches a json_pointer as a plain type or a
plain reference, so a const-qualified reference (as produced when KeyType
is deduced from a json_pointer argument) fell through to
is_comparable_no_json_pointer, which instantiates the deprecated
json_pointer/string comparison operators. This made ordered_json's
transparent comparator (and any transparent comparator on a custom string
type) warn under -Wdeprecated-declarations when calling
value(json_pointer, default), even though no such comparison is ever
performed. at() was already fixed for this in #5289, which does not use
is_comparable_with_object_key.

Strip references and cv-qualifiers with uncvref_t before the
is_json_pointer_of dispatch, so any reference-to-json_pointer is
recognized regardless of qualifiers.

Fixes #5664.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 20:06:59 +02:00
Niels Lohmann 93231c6c2f Factor the repeated JSON_HAS_RANGES/MinGW guard into one macro
The std::ranges view conversion (excluded on MinGW because of its
incomplete C++20 ranges support, #4916) was gated by the same
#if JSON_HAS_RANGES && !defined(__MINGW32__) condition at seven
independent sites in to_json.hpp and type_traits.hpp, with the MinGW
rationale duplicated in two of them and missing from the rest. Since the
sites come in matching pairs (one enables is_compatible_range_view and a
view-based overload, the other adds the exclusion to the
plain-array-type overload), a drift between any pair would produce an
ambiguous or missing overload on exactly one platform.

Add JSON_HAS_RANGE_VIEW_CONVERSION next to JSON_HAS_RANGES in
macro_scope.hpp, combining both conditions with the #4916 reasoning in
one place, #undef it in macro_unscope.hpp, and use it at all seven
sites. This does not fold the MinGW check into JSON_HAS_RANGES itself:
JSON_HAS_RANGES is user-overridable and also gates the
enable_borrowed_range specialization in iteration_proxy.hpp, which is
not excluded on MinGW.

No behavior or public API change: JSON_HAS_RANGE_VIEW_CONVERSION expands
to exactly the condition that was previously written out at each site.

Overlaps #5585, #5600 and #3575, which touch the same to_json.hpp and
type_traits.hpp lines; the change here is a mechanical
search-and-replace of the guard condition and should rebase cleanly.

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

#5708 item 11
2026-09-30 18:12:58 +02:00
Niels Lohmann b5fad30499 Fix misplaced and stale comments in JSON_HAS_RANGES and conversions
The JSON_HAS_RANGES feature-detection block had its libc++ comment
sitting above the clang+libstdc++ branch it does not describe,
leaving the libc++ branch uncommented and the clang+libstdc++ branch
without its own rationale. Move each comment to sit under its own
branch, and give the clang+libstdc++ branch (added in issue 5161) its
own one-line reason referencing that issue instead of reusing the
libc++ branch's comment. Also fix a duplicated-word typo ("in large
in large cpp files") in from_json.hpp, drop two unanswered 2017
design questions left as comments in type_traits.hpp and
from_json.hpp that no longer reflect open questions, and correct
NLOHMANN_JSON_SERIALIZE_ENUM_STRICT's @since tag from 3.12.0 to
3.13.0, the release it was actually introduced in.

Part of #5708

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 10:11:36 +02:00
Niels Lohmann ae9ef9dde1 Simplify is_ordered_map to reuse has_capacity
is_ordered_map re-detected capacity() with a C++03 sizeof/vararg
trick right after has_capacity did the same detection through
is_detected. For ordered_map, the old trick took the address of
std::vector::capacity, which [namespace.std]/6 makes unspecified.
Reuse has_capacity instead, which removes the unspecified-behavior
pointer-to-std-member and two NOLINT suppressions.

Part of #5708

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 09:50:52 +02:00
Niels Lohmann f9d4b51455 Remove unused would_call_std_* from NLOHMANN_CAN_CALL_STD_FUNC_IMPL
Besides detail::result_of_begin/end, which is_range and iterator_t use,
the macro defined a namespace detail2 with a tag type, a catch-all
overload and would_call_std_begin/end, plus would_call_std_begin/end
structs directly in namespace nlohmann. Nothing has used them since
they were added in #3020.

Reduce the macro to its detail part. Without the trailing struct the
';' after the two invocations would be an empty declaration that
-Wextra-semi flags, so drop it. macro_scope.hpp included
meta/detected.hpp only for this macro; all users of detected.hpp
include it (or type_traits.hpp) themselves, so remove the include.

Behavior and ABI are unchanged. The undocumented, untested and unused
names nlohmann::would_call_std_begin, nlohmann::would_call_std_end and
namespace nlohmann::detail2 are no longer declared.

Part of #5708

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 09:46:04 +02:00
Niels Lohmann 31883d06a8 Replace meta/logic.hpp with a disjunction trait
meta/logic.hpp added a second set of type-level boolean helpers
(cxpr_and, cxpr_or, cxpr_not, ...) next to the existing conjunction
and negation in type_traits.hpp. It was used only by one static_assert
in from_json_tuple_impl, two of its templates were never used, and it
was the only header without the license banner and relied on
transitive includes for <type_traits>.

Add the missing disjunction next to conjunction and negation, use the
three in the static_assert, and delete logic.hpp together with its
BUILD.bazel entry. same_sign now uses disjunction as well, which
resolves the 2022 TODO waiting for such a trait.

The static_assert accepts and rejects the same types as before. Only
names in nlohmann::detail change; behavior, public API and ABI are
unchanged.

Part of #5708

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 09:42:12 +02:00
Niels Lohmann 4c208728e7 Remove unused is_sax and is_detected_convertible
detail::is_sax had no user: the parser and the binary reader only use
is_sax_static_asserts, so is_sax was a second, unchecked copy of the
SAX event list. is_sax_static_asserts asserted boolean(bool) twice in
a row, and detail::is_detected_convertible was never used anywhere.

Remove all three and include <cstddef> for size_t instead of <cstdint>.
Only names in nlohmann::detail are removed; behavior, public API and ABI
are unchanged. The diagnostics for an incomplete SAX handler are the
same, apart from the duplicated boolean() message.

Part of #5708

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 09:38:54 +02:00
Niels LohmannandClaude Opus 5 c72f37a40d Support custom object/array types and improve template parameter handling (#5443)
* docs: document the implicit requirements on basic_json's template parameters

The requirements that basic_json places on its eleven template parameters
were only implied by how the library uses the resulting object_t, array_t,
string_t, etc. Consumers had to discover them by trial and error.

Add "Template Parameter Requirements" collecting them, split into what is
always required and what is only required when a particular part of the API
is instantiated. Notable findings that were previously undocumented:

- ObjectType must provide a key_compare member type (actual_object_comparator
  names object_t::key_compare in both arms of a std::conditional), and its
  third template parameter is used as a comparator, so std::unordered_map
  cannot be used without a wrapper.
- ArrayType must provide capacity() -- push_back(), emplace_back(),
  operator+=(), and operator[](size_type) call it unconditionally -- and
  needs random-access iterators, so std::deque and std::list do not work.
- StringType needs contiguous, null-terminated data(), a one-byte value_type,
  and either assignability from std::to_string or an ADL int_to_string().
- NumberFloatType must be float, double, or long double for parsing and
  serialization; the integer types must satisfy std::is_integral.
- AllocatorType must be stateless, support incomplete types, and use plain
  pointers.
- BooleanType and the number types are union members and must be trivial.

Link the new page from the basic_json overview, the types feature page, and
the individual type alias pages, and correct the container examples given for
ObjectType (std::unordered_map) and ArrayType (std::list), which do not work.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Fix object_comparator_t for object types without key_compare

detail::actual_object_comparator selected between object_t::key_compare and
default_object_comparator_t with std::conditional. Both type arguments of
std::conditional are named eagerly, so object_t::key_compare had to exist
regardless of the condition, and the has_key_compare guard added in 3.11.0
never took effect: any ObjectType without a key_compare member type failed to
compile while instantiating basic_json itself.

Use detected_or_t instead, which resolves through a SFINAE partial
specialization and only names object_t::key_compare when it exists. The
selected type is unchanged for every object type that compiled before, so
object_comparator_t -- a public member type -- keeps its meaning and ABI.

has_key_compare had no other users and is removed.

Add a regression test using an adapter around std::unordered_map, which has no
key_compare; it fails to compile without this change.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* docs: list the types that are known to work for each template parameter

Follow up on the template parameter requirements page: state, for every
template parameter, which concrete types work and where they stop working.
Each entry was verified by compiling and running a common workload (DOM
access, dump, parse, CBOR/MessagePack round-trip, flatten, hash) against that
instantiation.

Findings worth calling out:

- ObjectType no longer needs a key_compare member type, so the std::unordered_map
  adapter only has to restore the template argument order. A hash-ordered
  ObjectType works everywhere except unflatten(), which reconstructs an array
  only when it meets the reference token 0 before the other indices.
- ArrayType: std::deque works when wrapped to add capacity(); std::list does not.
- StringType: std::pmr::string and std::basic_string with a custom allocator
  compile for the DOM, dump, and parse, but not for the binary readers, flatten,
  or diff, because the library assigns std::string values to string_t and
  int_to_string cannot be overloaded for a type in namespace std.
- NumberFloatType: long double works for dump and parse but not for the binary
  formats, which have no encoding for it.
- BinaryType: std::vector<std::byte> supports assignment, get, and the binary
  formats, but neither dump nor std::hash<basic_json>.

Also record the object_comparator_t fix in its version history.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Fix unflatten and binary dumping for non-default configurations

unflatten() decided between array and object by looking at the first reference
token it happened to see for a node: it started an array only when that token
was 0. With a sorted object type the token 0 always arrives first, so the
result was correct by accident; with an object type whose iteration order is
unspecified, {"/c/2":3,"/c/1":2,"/c/0":1} unflattened to an object with the
keys "0", "1", and "2" instead of an array.

Collect the pointer prefixes that have a reference token 0 among their children
before building the result, and let get_and_create() consult that set. The
outcome is now independent of the iteration order and matches, for every input,
what a sorted object type produced before: a value is restored as an array if
and only if one of its keys is 0. Iterating the flattened object in a different
order would have been simpler, but it would have changed the key order of the
result for insertion-ordered object types.

The serializer, std::hash, and the UBJSON writer converted the elements of a
binary value to an integer implicitly, which does not compile for a BinaryType
whose value type is std::byte, and which made dump() write the bytes of a
signed value type as negative numbers. Convert to std::uint8_t explicitly in
all three places, so every byte type dumps as 0..255. The default
std::vector<std::uint8_t> configuration is unaffected.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* docs: note which Abseil containers can be used as template arguments

Checked against Abseil release 20250127.0 with the same workload as the other
entries on the page (DOM access, dump, parse, CBOR/MessagePack/UBJSON
round-trip, flatten, hash), with and without JSON_DIAGNOSTICS.

absl::flat_hash_map and absl::node_hash_map work as ObjectType through an
adapter that restores the template argument order and makes erase(iterator)
return the following iterator, which Abseil's returns as void. The page now
carries that adapter, and notes that absl::flat_hash_map does not keep
references to the mapped values valid across insertions while
absl::node_hash_map does. Both have a capacity() member, so JSON_DIAGNOSTICS
already refreshes the parent pointers conservatively for them.

absl::btree_map and absl::InlinedVector cannot be used at all: object_t and
array_t are formed while basic_json is still incomplete, and both inspect
their value type at class scope. std::map and std::vector are required by the
standard to tolerate this, third-party containers generally are not, so the
page states the constraint on its own rather than only per container.

absl::InlinedVector does work as BinaryType, where it is instantiated with a
complete type. absl::FixedArray and absl::Cord are not usable.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Relax the ArrayType and ObjectType requirements

Two requirements forced users of otherwise suitable containers to write a
wrapper, and neither was load-bearing.

array_t::capacity() was read in push_back(), emplace_back(), operator+=(), and
operator[](size_type), but set_parent() only looks at the value under
JSON_DIAGNOSTICS; without diagnostics it was computed and discarded. Read it
through array_capacity(), which reports unknown_size() when diagnostics are off
or when the array type has no capacity() at all, and treat an unknown capacity
as "the elements may have moved" so the parent pointers are refreshed
conservatively. std::deque now works as ArrayType, in both builds, and
capacity() is no longer named at all in a default build. Since the capacity is
now only meaningful for array insertions, it moves out of set_parent() into
set_parent_after_array_insert().

basic_json::erase(iterator) assigned the object's erase() return value, which
requires the container to return the following iterator. Abseil's hash maps
return void to avoid computing a successor the caller may not need. Detect that
and compute the successor before erasing; containers that return an iterator,
including the vector-backed ordered_map where a precomputed successor would be
wrong, keep the existing path.

Together these leave an Abseil hash map needing only an alias that restores the
template argument order, and no adapter at all for std::deque.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Do not require string_t to be convertible from std::string

Three places built a std::string and handed it to something expecting a
string_t: the UBJSON high-precision number reader, which every binary reader
instantiates, and the BSON writer's array element size calculation and write.
That silently required string_t to be implicitly convertible from std::string,
which std::string itself and types with a string_view conversion satisfy, but
many string types do not.

Construct the string_t explicitly from the data and size, which the
requirements already cover. This makes boost::container::string, eastl::string,
std::pmr::string, and std::basic_string with a custom allocator work as
StringType, none of which could previously be used with any binary format.

Add binary format coverage to the alt_string test, which had none, including a
UBJSON high-precision number -- the case that goes through the reader path.
BSON stays uncovered there: it additionally needs string_t::find(value_type),
which alt_string does not provide.

Also record which containers from Boost, Abseil, and EASTL work for each
template parameter, and correct two claims: std::pmr::string is usable after
this change, and tsl::ordered_map is not usable at all, because its iterators
expose the mapped value as const while basic_json modifies it in place.

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

* docs: record compatibility for the common header-only hash maps

ankerl::unordered_dense (map and segmented_map), phmap (flat_hash_map and
node_hash_map), and robin_hood::unordered_flat_map all work as ObjectType
through the same adapter as Abseil's and Boost's hash maps, which only has to
restore the template argument order.

phmap::btree_map and robin_hood::unordered_node_map do not: like the other
btree containers they require a complete value type.

Note that none of these hash maps defines key_compare, so every one of them
depends on object_comparator_t falling back to default_object_comparator_t.

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

* docs: record Folly and the remaining vector replacements

Folly works, with the caveat that its headers need C++20: folly::fbstring as
StringType, folly::fbvector and folly::small_vector as ArrayType,
folly::fbvector<std::uint8_t> as BinaryType, and folly::F14NodeMap as
ObjectType through the usual argument-order adapter. folly::F14FastMap is the
exception and requires a complete value type.

For ArrayType, boost::container::devector, boost::container::static_vector
(within its fixed capacity), and std::pmr::vector work as well.

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

* docs: cover fifo_map, gtl, folly::sorted_vector_map, and Qt

nlohmann::fifo_map works through the adapter that has always been documented
for it, and preserves the insertion order. Restore its mention in the object
order page, which was dropped together with the tsl::ordered_map one: unlike
ordered_map it keeps a lookup index, so it is the insertion-ordered option
without the quadratic cost.

gtl::flat_hash_map and folly::sorted_vector_map work as well, the latter
through an alias that drops the allocator, whose value type it disagrees on.
gtl::btree_map does not, for the same reason as the other btree containers.

None of the Qt containers can be used, each for its own reason: QMap has no
value_type, QHash iterators yield the mapped value rather than a pair, QList
has no max_size(), QByteArray spells empty() as isEmpty(), and QString is
UTF-16.

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

* docs: qualify the std::pmr::string support claim

Listing std::pmr::string as fully supported was an overclaim: it was only ever
checked with the default memory resource, which is not what PMR is for.

basic_json cannot be given an allocator or a memory resource, so a pmr string
inside a value always allocates from std::pmr::get_default_resource(), and
assigning an arena-backed string into a value silently drops its resource,
because polymorphic_allocator does not propagate on copy construction. Passing
polymorphic_allocator as AllocatorType does not compile either. Only the
process-global set_default_resource() redirects these allocations.

Say so, and separate the row from std::basic_string with a custom stateless
allocator, which is unaffected.

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

* docs: remove a duplicated StringType compatibility section

The StringType section carried two 'Compatible types' tables and two copies of
the reference-implementation tip. The second table was a stale copy from before
the binary format string fixes and still listed std::pmr::string and
std::basic_string with a custom allocator as unusable, contradicting the
corrected table a few lines above it, and it dragged along the old explanation
that blamed int_to_string.

Drop the stale copy and put the surviving table before the notes, so the
'see below' in the std::pmr::string row points forwards.

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

* docs: correct the template parameter requirements after independent verification

Every claim on the page was re-checked by compiling and running it, including
the rows that say a type cannot be used, which were checked to fail for the
documented reason and not merely to fail. Twenty-four claims were wrong.

The most consequential: the incomplete-type constraint applies to ObjectType
only. object_t is instantiated inside the class definition, because it is
probed for key_compare; array_t is only named there and is not instantiated
until basic_json is complete. So eastl::vector, QList and QVector are not
excluded by incomplete types at all -- they simply have no max_size() -- and
absl::InlinedVector is excluded for a subtler reason of its own.

Further corrections: ObjectType does not need erase(key), which has a fallback,
but does need at(key) for UBJSON output; only == and < are used, or == and <=>
under C++20, not all six; the documented adapter does not fit ankerl or
robin_hood. ArrayType needs no initializer-list insert, and value_type, the
(count, value) constructor and swappability are per-function, not always.
BinaryType needs a range insert for CBOR indefinite-length byte strings and
does not need push_back. StringType needs append(const StringType&)
unconditionally, and does not need operator!= or operator== against const
char*; empty(), resize(n) and reserve(n) are per-subsystem; int_to_string is
needed by diff, items and std::hash rather than by JSON Pointer or flatten.
BooleanType must be implicitly convertible from bool, and JSONSerializer's
second parameter need not carry a default.

std::pmr::string was wrong in the other direction this time: a moved-in string
does keep its memory resource, and later growth allocates from it. Only copies
land on the default resource.

Five requirement violations are not caught at compile time rather than the two
the page claimed; they are now listed together up front. Split every
compatibility table into what works and what does not, as the reasons in the
second half are the useful part.

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

* Reduce the string_t and array_t members the library requires

Several members were required only because of how the library happened to
be written, not because the functionality needs them. Dropping them widens
the set of usable string and array types, and one of them was also a
performance problem.

string_t:

- c_str() is gone. Every call site already knew the length and passed it
  along, so data() is enough. The one place that did not, the diagnostics
  path in exceptions.hpp, now builds the token from data() and size(),
  which also stops it from truncating keys that contain a null byte.
- back() is gone; the serializer indexes the last character instead.
- find(str, pos), replace(), and substr() are gone. escape() and
  unescape() rebuilt the string with one replace() per escaped character,
  which moves the tail every time: escaping a string of n characters that
  all need escaping cost O(n^2). Both now scan with find_first_of() -- a
  member the pointer parser already required -- and append whole runs, so
  the common case is one search and one copy. Escaping 64000 tildes drops
  from 717 ms to 20 ms; a string with nothing to escape gets faster too
  (8.4 ms to 5.8 ms), because the scan is still a single memchr per pass.
  json_pointer::split() takes its reference tokens with the
  (const char*, size_type) constructor rather than substr().
- json_pointer::to_string() accumulates with concat<string_t> instead of
  letting concat default to std::string and converting afterwards, so
  streaming a json_pointer no longer requires string_t to be assignable
  from a std::string.

array_t:

- at(size_type) is gone. basic_json::at(size_type) checked the index by
  calling array_t::at() and translating std::out_of_range, which also
  required the array type to throw that exact exception. It now compares
  against size() and uses operator[]. The thrown exception, its message,
  and the behaviour under JSON_NOEXCEPTION are unchanged.

The BSON writer wrote the terminating null byte out of the string's own
buffer (size() + 1). It now writes the byte itself, so string_t::data()
need not be null-terminated for to_bson().

The tests pin the reduced API: alt_string loses the five dropped members
and gains coverage of the escaping paths, and a std::vector whose at() is
hidden is used as an ArrayType.

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

* docs: record the reduced string_t and array_t requirements

Drop c_str(), back(), find(str, pos), replace(), and substr() from the
StringType requirements and at(size_type) from the ArrayType ones, and
note the string assignment the JSON pointer code performs. Streaming a
json_pointer no longer needs assignability from a std::string.

Add the non-null-terminated data() to the list of violations that are not
diagnosed at compile time -- it was described in the StringType section
but missing from the summary at the top -- and correct the QString row,
which no longer fails for the c_str() it lacks.

JSON_CATCH_USER no longer wraps a catch of std::out_of_range: the last one
went away with array_t::at(). Describe what the library actually catches.

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

* Use character literals for the signed BinaryType test

MSVC rejects char(0xFF) with C4310 (cast truncates constant value),
which the Windows workflow treats as an error. The character literals
carry the same byte values without a narrowing cast.

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

* Do not instantiate a hash map with an incomplete basic_json in the tests

object_t is probed for key_compare inside the definition of basic_json, so
it is instantiated while basic_json is still incomplete. Whether a hash map
survives that depends on the standard library: libstdc++ 9 needs the size of
the mapped type to instantiate std::unordered_map's node type and rejects
the adapter, which broke the GCC 9 builds.

The test now derives its no-key_compare object type from std::map -- which
does cope -- and shadows the inherited key_compare member type with an
entity that is not a type, so the library's probe finds none, exactly as for
a hash map. The unflatten() order-independence checks in unit-json_pointer
already cover the behaviour that the unordered object type was there for.
The limitation is documented for std::unordered_map.

Also address two Clang-Tidy findings the earlier commits introduced:
erase_from_object() declares its iterator with auto, and at(size_type) checks
the type first and then falls through to the return instead of throwing from
an else branch.

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

* Keep diagnostic key paths null-terminated

Building the token from data() and size() kept an embedded null byte in the
key, and since what() hands out a C string, that truncated the whole message
rather than just the key: to_bson() on a key containing U+0000 reported
"[json.exception.out_of_range.409] (/en" instead of the full explanation.
This broke test-bson under JSON_DIAGNOSTICS.

Constructing from data() alone stops at the first null byte, which is what
c_str() did before, so the message is unchanged -- without requiring
string_t to provide c_str().

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

* Do not parse the value in the array-at() test

JSON_DIAGNOSTIC_POSITIONS adds the byte range of the value to the exception
message, which a parsed value has and an in-memory one does not, so the two
message checks failed in that configuration. Build the array in memory
instead of parsing it; the test is about at(size_type) not needing
array_t::at(), and the byte range is beside the point.

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

* Move the custom BinaryType tests into their own translation unit

The two sections added to unit-regression2.cpp brought a third full
basic_json instantiation into a translation unit that was already large.
With Clang on MinGW that pushed the object over the reach of a 32-bit
relocation and test-regression2_cpp20.exe failed to link:

    relocation truncated to fit: IMAGE_REL_AMD64_REL32 against `.rdata'

unit-regression2.cpp is restored to exactly what it was before, and the
coverage moves to unit-custom-binary-type.cpp, next to the object and array
type tests it belongs with. The signed value type is now also covered in
C++11, where std::byte is not available.

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

* Do not require the container iterators to be nothrow move constructible

iter_impl declared its defaulted move operations noexcept. The exception
specification a defaulted function gets implicitly follows from its members,
here internal_iterator, which holds the object and array iterators. libstdc++
gives std::deque's iterator a user-provided copy constructor without noexcept
before version 11, so the implicit specification is noexcept(false) and does
not match the declared one. That deletes the function -- and with g++ 4.8,
which predates CWG 1778, it is an error outright:

    error: function 'iter_impl<basic_json<std::map, std::deque> >::iter_impl(
    iter_impl&&)' defaulted on its first declaration with an
    exception-specification that differs from the implicit declaration

So std::deque, which this branch documents as a usable array type, could not
be used with an older standard library. Leaving the specification to be
computed cannot mismatch; iteration_proxy_value already spells out the same
condition next door.

The default configuration is unaffected: json::iterator, json::const_iterator
and ordered_json::iterator stay nothrow move constructible and move
assignable, which the test now checks so it cannot regress unnoticed.

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

* Address two Clang-Tidy findings the custom container tests exposed

Both come from instantiating basic_json with containers other than the
default ones, and neither shows up with the Clang-Tidy version available
outside CI:

- insert(const_iterator, basic_json&&) forwards its by-value iterator to
  the const-reference overload. performance-unnecessary-value-param asks
  for the copy to be a move; it only fires for an iterator that is not
  trivially copyable, as std::deque's is not. The NOLINT on the function
  does not cover it, because the finding is reported where the parameter
  is used rather than where it is declared. Move it, which is what the
  check asks for and is a (very small) improvement in its own right.

- cppcoreguidelines-use-enum-class rejects the unnamed enum that shadowed
  the inherited key_compare member type. An enum class would not do, since
  it declares a type of that name and the probe would find it again; a
  member function declaration hides the name just as well.

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

* Assert the iterators' exception specification relative to the container

The test pinned that nlohmann::json's iterators stay nothrow movable after
iter_impl's defaulted move operations lost their declared noexcept. That is
not a property of the library, though: the exception specification is now
computed from the container iterators, so it holds only for standard library
implementations whose iterators are themselves nothrow movable.

MSVC's checked iterators before VS2017 are not -- _Iterator_base12 registers
the iterator with the container's debug proxy in a copy constructor that
carries no noexcept -- so the assertions fail on a Visual Studio 2015 debug
build, which is the one debug configuration in the AppVeyor matrix and has no
counterpart in the GitHub Actions matrix.

Assert what the change actually guarantees instead: the iterators are nothrow
movable exactly when the object and array iterators they are built from are.
That still pins the default configuration against a silent regression, and it
is true whatever the standard library provides.

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

* Detect a void-returning erase() through a named trait

erase_from_object() distinguished its two overloads with a decltype of a
member call written inline in a default template argument. Every other
detection in the library goes through the detector machinery in detected.hpp
instead -- has_erase_with_key_type is the same question about the same member
function -- and the inline form is the one shape older compilers are least
reliable about.

Express it the same way: detect_erase_with_iterator plus is_detected_exact,
both of which the library already relies on elsewhere. No behaviour changes.

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

* Give the custom container types only the constructors the library uses

The three container types in the new tests inherited every constructor of
their base with using Base::Base. That asks for more than the test needs: the
library builds an object or an array by default construction, by copy or move,
and -- when converting between two basic_json types or from an initializer
list -- from an iterator range. Declaring those directly makes the requirement
visible in the test, and keeps object types out of a corner where a compiler
has to declare std::map's whole constructor set for a derived class while
basic_json is still incomplete.

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

* Temporarily disable the new custom container tests

AppVeyor is the only CI that builds MSVC 2015 and 2017, and it has now
rejected three heads of this branch. Its build log is not reachable from
where this is being worked on, so the verdict is a single bit and the cause
has to be narrowed down by bisection.

Everything else stays: the library changes, the reduced alt_string, and the
unflatten() tests. If AppVeyor passes with these three translation units
disabled, the cause is one of the six basic_json instantiations they add; if
it fails, it is in the library. Either way this commit is reverted.

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

* Guard the disabled tests with a macro rather than #if 0

Clang-Tidy's readability-avoid-unconditional-preprocessor-if rejects a literal
#if 0. Use a macro that is never defined instead, which the check does not
look at. Still temporary, and reverted together with the previous commit.

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

* Re-enable the array and binary container tests

AppVeyor passed with all three new translation units disabled, so the library
changes, the reduced alt_string, and the unflatten() tests are fine on MSVC
2015 and 2017; the cause is one of the six basic_json instantiations the new
tests add.

Bring back two of the three. If AppVeyor passes again, the cause is in
unit-custom-object-type.cpp, which is the one still disabled; if it fails, it
is in one of these two and needs one more split. Still temporary.

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

* Diagnose two silently violated template parameter requirements

Both were on the list of requirements that are not caught at compile time and
corrupt values rather than failing, and both are a plain size comparison:

- A BinaryType whose value_type is wider than one byte, which the readers and
  writers reinterpret as raw bytes anyway.
- A NumberUnsignedType too narrow to hold the absolute value of every
  NumberIntegerType value, which makes basic_json(INT64_MIN).dump() yield -0
  for std::int64_t with std::uint32_t.

Neither static_assert rejects a configuration that worked before: both only
fire where the result was already wrong. Also add the two comments the review
asked for, in write_bson_string() and calc_bson_array_size(), matching the
ones their counterparts already carry.

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

* Align the template parameter tables and record what is now diagnosed

Every table in the page is reformatted so each column is exactly as wide as
its widest cell, which is what the review asked for in a dozen places: the
separator rows that ran two dashes long, the stray spaces, and the columns
padded well past their content.

The row listing six containers that require a complete mapped type is split
in two so that one cell no longer sets the width of the whole table.

Content changes: NumberUnsignedType is described as any unsigned integer type
at least as wide as NumberIntegerType rather than any unsigned integer type;
the two requirements that are now static_asserts move out of the list of
violations that are not caught at compile time; and the two places that
require a non-const operator[] say why data() will not do (std::string has no
non-const data() before C++17).

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

* Bisect the other way: only the object container tests

The previous head touched only docs/, which AppVeyor's only_commits filter
skips, so it produced no build and no status at all -- the pull request looked
green without ever having been built on MSVC 2015 or 2017.

Swap the guards instead of repeating that step: unit-custom-object-type.cpp is
enabled and the array and binary translation units are disabled. AppVeyor
already passed with all three disabled, so a failure here pins the cause on
no_key_compare_json or void_erase_json, and a pass pins it on the array or
binary file. Still temporary.

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

* Split the two object types apart

AppVeyor failed with only unit-custom-object-type.cpp enabled and passed with
all three new translation units disabled, so the cause is one of the two
object types in this file and not the array or binary ones.

Guard out void_erase_map and leave no_key_compare_map, which separates the two
constructs under suspicion: shadowing the inherited key_compare member type
with an entity that is not a type, and hiding the inherited erase with a
void-returning overload. A failure here points at the first, a pass at the
second. Still temporary.

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

* Build the no-key_compare object type by composition, not inheritance

The "object type without key_compare" test failed on AppVeyor's MSVC
2017 jobs (/std:c++17): its no_key_compare_map derived publicly from
std::map and shadowed the inherited key_compare type with a same-named
member function, relying on ordinary member hiding to make key_compare
unreachable as a type for the library's detection trait. MSVC 2017
does not honor that hiding for a typename-qualified lookup performed
from outside the class and still resolves key_compare to the base's
comparator type, so object_comparator_t incorrectly picked it up
instead of falling back to default_object_comparator_t.

Wrapping a std::map by composition instead removes the base class
entirely, so there is no key_compare to find under any lookup rule,
on any compiler. Also drops the now-unneeded JSON_BISECT_CUSTOM_CONTAINER_TESTS
guard left over from narrowing this down: the void_erase_map test in
the same file was never the cause and is re-enabled unconditionally.

Verified locally with clang++ and g++ under C++17 and C++20.

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

* Re-enable the array and binary custom-container tests

unit-custom-array-type.cpp and unit-custom-binary-type.cpp were still
guarded behind JSON_BISECT_CUSTOM_CONTAINER_TESTS from bisecting the
AppVeyor failure fixed in 7c39f3227, which was unrelated to either
file. The macro was never defined, so none of these tests actually ran
in CI. Verified locally with clang++ and g++ under C++17 and C++20
before removing the guards.

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

* Fix indentation of custom_object_type per astyle

The one-line function bodies in the composition-based no_key_compare_map
(7c39f3227) do not match the project's Allman brace style, which the
ci_test_amalgamation job enforces with astyle. Reformatted with the
pinned astyle 3.4.13; no functional change.

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

* docs: add compiled reference implementations for the container template parameters

Each of ObjectType, ArrayType, StringType, and BinaryType now links to a
minimal, self-contained header (docs/mkdocs/docs/examples/custom_*_type.hpp)
that wraps the corresponding standard container by composition and satisfies
every "Always required" member listed on that page. Unlike the prose
requirement lists, these are real code: each header has a companion .cpp that
instantiates a basic_json specialization with it and is compiled and run by
the existing ci_test_examples check (docs/Makefile's check_output_portable),
so the reference implementations cannot silently drift from what the library
actually requires. The .output files were generated with that same target.

StringType's existing pointer to tests/src/unit-alt-string.cpp's alt_string
is kept alongside the new header as a more thorough, battle-tested example.

Verified locally: astyle (pinned 3.4.13, project .astylerc) on the new files;
clang++/g++ under C++11/17/20 for each example against the amalgamated
header; `make check_output_portable` in docs/; `mkdocs build --strict` and
scripts/check_structure.py for the page itself.

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

* Declare no_key_compare_map's accessors noexcept

The GCC C++20 job builds with -Wnoexcept and -Werror, and the standard
library takes noexcept(c.begin()) and noexcept(c.end()) in ranges_base.h and
range_access.h. Forwarding to std::map without repeating its noexcept made
those expressions false, which the warning reports as an error:

  error: noexcept-expression evaluates to 'false' because of a call to
         no_key_compare_map<...>::begin()          [-Werror=noexcept]
  note:  but ... does not throw; perhaps it should be declared 'noexcept'

Give the accessors the exception specification of what they forward to.
std::map declares begin, end, cbegin, cend, empty, size, max_size, and clear
noexcept, so the wrapper does too. swap is left alone: std::map's is only
conditionally noexcept, and nothing asks for it.

void_erase_map is unaffected because it still derives from std::map and
inherits accessors that already carry the specification.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Write out what the defaulted constructor of no_key_compare_map implied

ci_test_gcc builds with -Weffc++, which asks for data to be initialized in a
member initialization list; a defaulted default constructor does not do that:

  error: 'no_key_compare_map<...>::data' should be initialized in the member
         initialization list                              [-Werror=effc++]

Writing the constructor out satisfies that but drops the exception
specification the defaulted one carried, which -Wnoexcept then objects to
where the standard library takes noexcept(construct(...)). Declare it the way
the defaulted constructor was: noexcept when the wrapped map's default
constructor is.

This is the cost of composition -- inheritance carried std::map's exception
specifications and initialization for free, and forwarding by hand has to
restate them.

Checked with the repository's own GCC warning set from cmake/gcc_flags.cmake,
all 346 flags, at C++11, C++17 and C++20: no diagnostics for this file, nor
for the two custom container translation units that were disabled while the
MSVC failure was narrowed down and are built again now.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Mark no_key_compare_map::swap noexcept

Clang-Tidy rejects a swap that is not:

  error: swap functions should be marked noexcept
         [cppcoreguidelines-noexcept-swap,performance-noexcept-swap]

It was left unmarked on the grounds that std::map::swap is only
conditionally noexcept, so an unconditional promise would be wrong for a
comparator or allocator that can throw while swapping. Both concerns are met
by taking the specification from the wrapped map rather than asserting one:
noexcept(noexcept(data.swap(other.data))). Clang-Tidy accepts that, and no
NOLINT is needed.

Last in the series of specifications that inheritance used to supply and
composition has to write out by hand.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018hxZxz8svM54c6ATEvXp5E
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
2026-09-15 20:46:37 +02:00
Angadi56 5f121d8c50 avoid sign extension in char_traits<signed char>::to_int_type (#5336)
* avoid sign extension in char_traits<signed char>::to_int_type

Signed-off-by: Angadi Yashaswini <angadi@digiscrypt.com>

* spell out-of-range signed char constants as negative values (MSVC C4309)

Signed-off-by: Angadi Yashaswini <angadi@digiscrypt.com>

---------

Signed-off-by: Angadi Yashaswini <angadi@digiscrypt.com>
2026-08-03 08:35:53 +02:00
Niels Lohmann 585929bff9 Fix Clang deprecation warning for json_pointer operator== with ordered_json (#5289)
is_comparable used a flat && chain to both exclude json_pointer/string
comparisons (added for #4621) and check whether Compare(A, B) is well-formed.
Naming std::is_constructible<decltype(...)> as a later operand of that chain
still causes the decltype to be substituted regardless of the first
operand's value, since the operands aren't lazily deferred like
std::conjunction would defer them. That instantiates the transparent
std::equal_to<>::operator() used by ordered_json, whose noexcept-specifier
evaluates the deprecated json_pointer/string operator==, which Clang (unlike
GCC in this case) warns about even though the result is discarded.

Split is_comparable so the Compare(A, B) checks live in a separate helper
that is only referenced from the specialization selected when
is_json_pointer_of is false, so the decltype is never written when A/B are
a json_pointer/string pair, regardless of compiler.

Signed-off-by: Niels Lohmann <niels.lohmann@gmail.com>
2026-08-03 08:20:41 +02:00
Niels Lohmann fe2bcc080f Custom BinaryType direct assignment (#5266)
* Fix discussion #4209: custom BinaryType direct assignment and extraction

When a custom BinaryType is configured (other than the default std::vector<uint8_t>),
users can now:
1. Assign values of that type directly to create binary values (not arrays)
2. Extract binary values back to that type with get<>()
3. Extract arrays to that type (for backward compatibility)

Implementation:
- Add is_compatible_binary_type trait to centralize SFINAE condition
- Update to_json to accept custom BinaryType values directly
- Update from_json to handle both binary and array inputs for custom BinaryType
- Add #include <vector> with IWYU comment to from_json.hpp
- Add comprehensive tests for assignment and array extraction
- Update binary_t documentation with example

This is purely additive and invisible to the default nlohmann::json alias, which
continues to treat std::vector<uint8_t> as arrays.

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

* Fix CI: missing include and const-correctness

- Add #include <vector> to type_traits.hpp for the new
  is_compatible_binary_type trait's std::vector<std::uint8_t> reference
  (caught by cpplint's include-what-you-use check)
- Mark test-local json variables const where never reassigned
  (caught by clang-tidy's misc-const-correctness check)

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-07-11 15:09:05 +02:00
Federico Sfriso c60217e801 fix: support constructing json from C++20 range views (#4916) (#5205) 2026-07-11 09:13:04 +02:00
Daniel Falk c05c5e229b Add missing copyright notices to SBOM (#5241) 2026-07-07 20:00:49 +02:00
EALePain 25f48639c7 Reference tuple from json (#5016)
* Add reference handling to tuples

Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>

* Remove template template type because pair isn't working

Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>

* amalgamate std::tie changes

Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>

* allow the elation of a move by removing the ref requirement

Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>

* force all number_xxx_t to be interchangeable

Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>

* Finally got amalgamate to work correctly

Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>

* remove const version, add a test case for scrambled number representations.

Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>

* Use the logical set of requirements instead of decltype because VS 2015 doesn't like it

Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>

---------

Signed-off-by: Evelyn LePain <ava.lepain@gmail.com>
2026-01-23 08:14:55 +01:00
KhloodElhossinyandkhloodelhossiny 8f75700141 support types convertible to string_view as JSON keys (#4958)
Signed-off-by: khloodelhossiny <khloood.elhossiny@gmail.com>
Co-authored-by: khloodelhossiny <khloood.elhossiny@gmail.com>
2026-01-11 21:45:22 +01:00
Niels Lohmann 515d994acb 📄 adjust year (#5044)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-01-01 20:00:39 +01:00
Niels Lohmann 54be9b04f0 📄 update REUSE (#4960) 2025-10-23 06:56:36 +02:00
Niels Lohmann a63795caf1 🚨 avoid deprecation warning (#4791)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2025-10-22 21:27:35 +02:00
Niels Lohmann 30d27df61c Fix CI (#4871)
* 👷 fix CI

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

* 👷 fix CI

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

* 👷 fix CI

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

* 👷 fix CI

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

* 👷 fix CI

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

* 👷 fix CI

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

* 👷 fix CI

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

* 👷 fix CI

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

* 👷 fix CI

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

* 👷 fix CI

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

* 👷 fix CI

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

* 👷 fix CI

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

* 👷 fix CI

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

* 👷 fix CI

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

* 👷 fix CI

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2025-07-31 20:10:57 +02:00
Niels Lohmann 9110918cf8 Fix typos (#4748)
* ✏️ fix typos

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

* ✏️ address review comments

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

* ✏️ address review comments

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2025-05-04 10:28:24 +02:00
Xiaochuan Ye 3b02afb9d9 Specialize char_traits for std::byte to fix from_msgpack (fixes #4756) (#4760)
* Specialize char_traits for std::byte to fix from_msgpack (fixes #4756)

Provide a char_traits<std::byte> specialization under __cpp_lib_byte
to allow parsing MessagePack data from containers of std::byte.

Signed-off-by: xuesongtap <tap91624@gmail.com>
Signed-off-by: yexiaochuan <tap91624@gmail.com>

* Fix comments for cstddef include and MessagePack tests

Signed-off-by: xuesongtap <tap91624@gmail.com>
Signed-off-by: yexiaochuan <tap91624@gmail.com>

* Fix include <cstddef> only when __cpp_lib_byte is defined and sufficient

Signed-off-by: yexiaochuan <tap91624@gmail.com>

* Fix clang-tidy warnings in MessagePack std::byte tests

Signed-off-by: yexiaochuan <tap91624@gmail.com>

* Fix handle return value in MessagePack tests

Signed-off-by: yexiaochuan <tap91624@gmail.com>

---------

Signed-off-by: xuesongtap <tap91624@gmail.com>
Signed-off-by: yexiaochuan <tap91624@gmail.com>
2025-04-28 16:19:47 +02:00
Niels Lohmann 1705bfe914 🔖 set version to 3.12.0 (#4727)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2025-04-11 10:41:14 +02:00
Niels Lohmann f06604fce0 Bump the copyright years (#4606)
* 📄 bump the copyright years

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

* 📄 bump the copyright years

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

* 📄 bump the copyright years

Signed-off-by: Niels Lohmann <niels.lohmann@gmail.com>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Signed-off-by: Niels Lohmann <niels.lohmann@gmail.com>
2025-01-19 17:04:17 +01:00
Niels Lohmann 6057b31df7 Overwork astyle call (#4573)
* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* Use ubuntu-latest image to run Valgrind (#4575)

* 🔧 use Clang image to run valgrind

* 🔧 use Clang image to run valgrind

* 🔧 use Clang image to run valgrind

* 🔧 use Ubuntu image to run valgrind

* Use Clang image to run iwyu (#4574)

* 🔧 use Clang image to run iwyu

* 🔧 use Clang image to run iwyu

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🔧 overwork astyle call

* 🎨 format code

* 🔨 clean up
2024-12-29 17:06:03 +01:00
Niels Lohmann 20ae363a71 Replace EOF with char_traits (#4532)
* 📝 update customers

* ♻️ replace EOF with char_traits #2755
2024-12-10 20:51:47 +01:00
Niels Lohmann 1b9a9d1f21 Update licenses (#4521)
* 📄 update licenses

* 📄 update licenses
2024-11-29 17:38:42 +01:00
Niels Lohmann 1825117e63 Another desperate try to fix the CI (#4489)
* 🚨 fix warning

* 💚 update actions

* 🚨 fix warning

* 🚨 fix warning

* 🚨 fix warning

* 💚 update actions

* 💚 update actions

* 🚨 fix warning

* 🚨 fix warning

* 💚 update actions

* 🚨 fix warning

* 💚 update actions

* 💚 update actions

* 💚 update actions

* 🚨 fix warning

* 🚨 fix warning

* 🚨 fix warning

* 🚨 fix warning

* 💚 update actions

* 💚 update actions

* 🚨 fix warning

* 💚 update actions

* 💚 update actions

* 💚 update actions

* 💚 update actions

* 💚 update actions
2024-11-13 10:21:26 +01:00
Niels Lohmann 9cca280a4d JSON for Modern C++ 3.11.3 (#4222) 2023-11-28 22:36:31 +01:00
Colby Haskell 1d597743d8 Fix char_traits deprecation warning (#4179) 2023-11-27 06:51:25 +01:00
Niels Lohmann f56c6e2e30 Update documentation for the next release (#4216) 2023-11-26 15:51:19 +01:00
Niels Lohmann 836b7beca4 Fix CI, again (#4083) 2023-09-07 20:41:12 +02:00
Niels Lohmann 9d69186291 🔖 set version to 3.11.2 2022-08-12 15:04:06 +02:00
Florian Albrechtskirchinger 0c7a18374c Reimplement value() access functions (#3663)
* Reimplement value() access functions

* Merges the 'const char *' with the 'ValueType &&' overloads.
* Fixes ambiguities when default value is 0.
* Fixes 'no matching function' error when specifying ValueType template
  parameter.
* Fixes incorrect template parameter order in previous overloads.

* Add additional value() tests

* Make JSON_MultipleHeaders visible to unit tests

Define the macro JSON_TEST_USING_MULTIPLE_HEADERS to 0/1 depending on
JSON_MultipleHeaders.

* Add type_traits unit test

* Update documentation
2022-08-07 13:54:55 +02:00
Florian Albrechtskirchinger 32242022f7 Minor BJData fixes (#3637)
* Replace vector/map LUTs in binary_reader with arrays

* Replace string_t::npos in binary_reader
2022-08-03 09:15:37 +02:00
Niels Lohmann f2020da0dd 🔖 set version to 3.11.1 2022-08-01 23:27:58 +02:00
Niels Lohmann ce0e13ccea 🔖 set version to 3.11.0 2022-07-31 23:19:06 +02:00
Niels Lohmann 9472ab4f84 Add license header to new files (#3633) 2022-07-31 07:22:22 +02:00
KsaNLandFlorian Albrechtskirchinger fc3e64cbf9 Fixed latest build error in msvc platform (#3630)
* Fixed latest build error in msvc platform

warnings in msvc about mix/max macro while windows.h is used in the project #762

* Update for CI

None

* Update single_include/nlohmann/json.hpp

Co-authored-by: Florian Albrechtskirchinger <falbrechtskirchinger@gmail.com>

Co-authored-by: Florian Albrechtskirchinger <falbrechtskirchinger@gmail.com>
2022-07-30 23:03:09 +02:00
Florian Albrechtskirchinger d909f80960 Add versioned, ABI-tagged inline namespace and namespace macros (#3590)
* Add versioned inline namespace

Add a versioned inline namespace to prevent ABI issues when linking code
using multiple library versions.

* Add namespace macros

* Encode ABI information in inline namespace

Add _diag suffix to inline namespace if JSON_DIAGNOSTICS is enabled, and
_ldvcmp suffix if JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON is enabled.

* Move ABI-affecting macros into abi_macros.hpp

* Move std_fs namespace definition into std_fs.hpp

* Remove std_fs namespace from unit test

* Format more files in tests directory

* Add unit tests

* Update documentation

* Fix GDB pretty printer

* fixup! Add namespace macros

* Derive ABI prefix from NLOHMANN_JSON_VERSION_*
2022-07-30 21:59:13 +02:00
Florian Albrechtskirchinger a87c1885cb Re-add value_type detection to distinguish string types (#3604)
* Re-add value_type detection to is_constructible_string_type trait

* Add value_type detection to from_json for strings
2022-07-28 21:52:23 +02:00
Niels LohmannandFlorian Albrechtskirchinger 527da54dcb Use REUSE framework (#3546)
* 📄 add licenses

* 👷 add REUSE compliance check

* 📝 add badge for REUSE

Co-authored-by: Florian Albrechtskirchinger <falbrechtskirchinger@gmail.com>
2022-07-20 12:38:07 +02:00
Florian Albrechtskirchinger 7d361ec8ef Add overloads for more key types to ordered_map and fix ordered_map::erase(first, last) with first == last (#3564)
* Add overloads for more key types to ordered_map

Add overloads to accept additional key types defined by type trait
detail::is_usable_as_key_type to ordered_map.
The same key types that can be used with json can now also be used with
ordered_json.

* Fix ordered_map::erase(first, last) with first == last

* Modify element access unit test to also test ordered_json
2022-07-04 19:58:19 +02:00
Niels Lohmann af34396129 Use new CI image (#3528)
* ⬆️ use new CI image

* ⬆️ use new CI image

* 🚨 fix warning

* 🔧 remove duplicate warning flags

* 💚 fix test

* 📝 update compiler versions
2022-06-12 14:31:07 +02:00
Florian AlbrechtskirchingerandQianqian Fang 48a102c2c5 Fix ndarray dimension signedness, fix ndarray length overflow (2); add 32bit unit test (#3523)
* Fix ndarray dimension signness, fix ndarray length overflow, close #3519

* detect size overflow in ubjson and bjdata

* force reformatting

* Fix MSVC compiler warning

* Add value_in_range_of trait

* Use value_in_range_of trait

* Correct 408 parse_errors to out_of_range

* Add 32bit unit test

The test can be enabled by setting JSON_32bitTest=ON.

* Exclude unreachable lines from coverage

Certain lines are unreachable in 64bit builds.

Co-authored-by: Qianqian Fang <fangqq@gmail.com>
2022-06-09 08:22:58 +02:00
Florian AlbrechtskirchingerandNiels Lohmann bdc21ad1a7 Add build step for ICPC (with fixes) (#3465)
* ⬆️ Doctest 2.4.7

* 👷 add CI step for ICPC

* 👷 add CI step for ICPC

* 👷 add CI step for ICPC

* ⬇️ downgrade to Doctest 2.4.6

* 👷 add CI step for ICPC

* 👷 add CI step for ICPC

* 👷 add CI step for ICPC

* 👷 add CI step for ICPC

* 👷 add CI step for ICPC

* 🔇 suppress warning #2196: routine is both "inline" and "noinline"

* Re-enable <filesystem> detection on ICPC

* Limit regression test for #3070 to Clang and GCC >=8.4

* Disable deprecation warnings on ICPC

* Disable regression test for #1647 on ICPC (C++20)

* Fix compilation failure of regression test for #3077 on ICPC

* Disable wstring unit test on ICPC

Fixes:
  error 913: invalid multibyte character sequence

* Add ICPC to README

Co-authored-by: Niels Lohmann <mail@nlohmann.me>
2022-05-01 22:46:45 +02:00
Florian AlbrechtskirchingerandNiels Lohmann 5352856f04 Implement support for string_view (attempt no. 3) (#3423)
* Add key_compare member to ordered_map

* Replace == with key_compare in ordered_map

* Expose the actual comparison function used by object_t

nlohmann::ordered_map uses a different comparison function than the one
provided via template parameter.
* Introduce a type trait to detect if object_t has a key_compare member.
* Rename object_comparator_t to default_object_comparator_t.
* Add object_comparator_t to be conditionally defined as
  object_t::key_compare, if available, or default_object_comparator_t
  otherwise.
* Update the documentation accordingly.

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

* Add type traits to check if a type is usable as object key

Add type trait to check:
* if a type is a specialization of a template.
* if a type is a json_pointer.
* if a type is a basic_json::{const_,}iterator.
* if two types are comparable using a given comparison functor.
* if a type is comparable to basic_json::object_t::key_type.
* if a type has a member type is_transparent.
* if a type is usable as object key.
* if a type has an erase() function accepting a given KeyType.

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

* Rework basic_json element access to accept more key types

Rework basic_json element access member functions and operators to
accept any type that meets the requirements defined by type trait
detail::is_usable_as_key_type.

Member functions and operators:
* at()
* operator[]
* value()
* erase()
* find()
* count()
* contains()

Update documentation to reflect these changes.

Add unit tests to excercise the new functions using std::string_view.

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>
2022-04-29 21:40:02 +02:00