Niels Lohmann 6ae17630a4 Reject integral keys for contains(), find(), and count() at compile time (#5705) ...

j.contains(0), j.find(0), and j.count(0) used to compile: the literal 0 is
a null pointer constant, so it converts to a null const char*, and the
overloads taking const typename object_t::key_type& accepted it by
constructing a std::string from that null pointer, which is undefined
behavior (a crash with both libc++ and libstdc++). value(0, default_value)
had the same problem in C++11, where the object comparator is not
transparent.

Add deleted overloads for integral arguments to contains(), find()
(const and non-const), count(), and value() so that these calls are
compile errors in every supported language mode instead of crashing.
Calls with string, string_view, json_pointer, and size-typed element
access (at(), operator[](), erase()) are unaffected.

Fixes #5657.

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

2026-09-30 20:07:45 +02:00

..

~basic_json.md

Documentation change (#3672)

2022-08-05 19:51:39 +02:00

accept.md

Document that a NUL byte in the input is treated as end of input (#5534)

2026-09-24 06:55:21 +02:00

array_t.md

Support custom object/array types and improve template parameter handling (#5443)

2026-09-15 20:46:37 +02:00

array.md

📝 add more docs (#5231)

2026-07-04 11:13:25 +02:00

at.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

back.md

📝 update documentation (#4723)

2025-04-05 18:54:35 +02:00

basic_json.md

Fix documentation gaps found in a full GitHub Discussions review (#5264)

2026-07-10 16:01:08 +02:00

begin.md

Reorganize directories (#3462)

2022-05-01 09:41:50 +02:00

binary_t.md

Support custom object/array types and improve template parameter handling (#5443)

2026-09-15 20:46:37 +02:00

binary.md

📝 update documentation (#4723)

2025-04-05 18:54:35 +02:00

boolean_t.md

Support custom object/array types and improve template parameter handling (#5443)

2026-09-15 20:46:37 +02:00

cbegin.md

Reorganize directories (#3462)

2022-05-01 09:41:50 +02:00

cbor_tag_handler_t.md

Fix documentation style check: wrap long line in cbor_tag_handler_t.md (#5603)

2026-09-27 20:40:13 +02:00

cend.md

Reorganize directories (#3462)

2022-05-01 09:41:50 +02:00

clear.md

Fix clear() to also reset the subtype of a binary value (#5680)

2026-09-30 20:06:51 +02:00

contains.md

Reject integral keys for contains(), find(), and count() at compile time (#5705)

2026-09-30 20:07:45 +02:00

count.md

Reject integral keys for contains(), find(), and count() at compile time (#5705)

2026-09-30 20:07:45 +02:00

crbegin.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

crend.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

default_object_comparator_t.md

Complete documentation for 3.11.0 (#3464)

2022-05-17 13:08:56 +02:00

diff.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

dump.md

Enhance documentation on serializing untrusted input in dump() (#5304)

2026-07-26 08:29:31 +00:00

emplace_back.md

📝 add more docs (#5231)

2026-07-04 11:13:25 +02:00

emplace.md

📝 add more docs (#5231)

2026-07-04 11:13:25 +02:00

empty.md

Fix typos (#4748)

2025-05-04 10:28:24 +02:00

end_pos.md

Clean up and document project files (#4560)

2025-01-17 06:53:35 +01:00

end.md

Reorganize directories (#3462)

2022-05-01 09:41:50 +02:00

erase.md

📝 add more docs (#5231)

2026-07-04 11:13:25 +02:00

error_handler_t.md

Overwork project infrastructure (#5218)

2026-06-30 18:09:06 +02:00

exception.md

Overwork documentation (#4516)

2024-12-09 23:02:30 +01:00

find.md

Reject integral keys for contains(), find(), and count() at compile time (#5705)

2026-09-30 20:07:45 +02:00

flatten.md

📝 update documentation (#4723)

2025-04-05 18:54:35 +02:00

format_as.md

Documentation review (#5257)

2026-07-09 17:24:19 +02:00

from_bjdata.md

Add BON8 support (#2998)

2026-09-27 16:56:21 +02:00

from_bon8.md

Add BON8 support (#2998)

2026-09-27 16:56:21 +02:00

from_bson.md

Add BON8 support (#2998)

2026-09-27 16:56:21 +02:00

from_cbor.md

Name the key type when rejecting non-string CBOR/MessagePack map keys (#5594)

2026-09-28 17:51:07 +02:00

from_msgpack.md

Name the key type when rejecting non-string CBOR/MessagePack map keys (#5594)

2026-09-28 17:51:07 +02:00

from_ubjson.md

Add BON8 support (#2998)

2026-09-27 16:56:21 +02:00

front.md

📝 update documentation (#4723)

2025-04-05 18:54:35 +02:00

get_allocator.md

Complete documentation for 3.11.0 (#3464)

2022-05-17 13:08:56 +02:00

get_binary.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

get_ptr.md

Overwork documentation (#4516)

2024-12-09 23:02:30 +01:00

get_ref.md

Fix return value of get_ptr for unsigned integers (#4525)

2024-12-06 18:38:25 +01:00

get_to.md

Improve error message for const fields (#2818)

2026-09-25 18:02:38 +02:00

get.md

Documentation review (#5257)

2026-07-09 17:24:19 +02:00

index.md

Add BON8 support (#2998)

2026-09-27 16:56:21 +02:00

input_format_t.md

Add BON8 support (#2998)

2026-09-27 16:56:21 +02:00

insert.md

Copy values before inserting an initializer list into an array (#5693)

2026-09-30 20:07:16 +02:00

invalid_iterator.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

is_array.md

Reorganize directories (#3462)

2022-05-01 09:41:50 +02:00

is_binary.md

📝 update documentation (#4723)

2025-04-05 18:54:35 +02:00

is_boolean.md

Reorganize directories (#3462)

2022-05-01 09:41:50 +02:00

is_discarded.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

is_null.md

Reorganize directories (#3462)

2022-05-01 09:41:50 +02:00

is_number_float.md

📝 update documentation (#4723)

2025-04-05 18:54:35 +02:00

is_number_integer.md

📝 update documentation (#4723)

2025-04-05 18:54:35 +02:00

is_number_unsigned.md

📝 update documentation (#4723)

2025-04-05 18:54:35 +02:00

is_number.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

is_object.md

Reorganize directories (#3462)

2022-05-01 09:41:50 +02:00

is_primitive.md

📝 update documentation (#4723)

2025-04-05 18:54:35 +02:00

is_string.md

Reorganize directories (#3462)

2022-05-01 09:41:50 +02:00

is_structured.md

📝 update documentation (#4723)

2025-04-05 18:54:35 +02:00

items.md

Fix documentation gaps found in a full GitHub Discussions review (#5264)

2026-07-10 16:01:08 +02:00

json_base_class_t.md

Support custom object/array types and improve template parameter handling (#5443)

2026-09-15 20:46:37 +02:00

json_serializer.md

Support custom object/array types and improve template parameter handling (#5443)

2026-09-15 20:46:37 +02:00

max_size.md

Adjust JSON Pointer examples (#3622)

2022-07-29 14:28:37 +02:00

merge_patch.md

Reorganize directories (#3462)

2022-05-01 09:41:50 +02:00

meta.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

number_float_t.md

Support custom object/array types and improve template parameter handling (#5443)

2026-09-15 20:46:37 +02:00

number_integer_t.md

Support custom object/array types and improve template parameter handling (#5443)

2026-09-15 20:46:37 +02:00

number_unsigned_t.md

Support custom object/array types and improve template parameter handling (#5443)

2026-09-15 20:46:37 +02:00

object_comparator_t.md

Support custom object/array types and improve template parameter handling (#5443)

2026-09-15 20:46:37 +02:00

object_t.md

Support custom object/array types and improve template parameter handling (#5443)

2026-09-15 20:46:37 +02:00

object.md

📝 add more docs (#5231)

2026-07-04 11:13:25 +02:00

operator_eq.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

operator_ge.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

operator_gt.md

Docs: fix typos of 'whether' in operator_{gt,le,lt}.md (#4412)

2024-07-07 10:22:17 +02:00

operator_le.md

📝 update documentation (#4723)

2025-04-05 18:54:35 +02:00

operator_lt.md

Docs: fix typos of 'whether' in operator_{gt,le,lt}.md (#4412)

2024-07-07 10:22:17 +02:00

operator_ne.md

Documentation review: fix stale version-history placeholder in operator_ne.md (#5261)

2026-07-09 20:57:41 +02:00

operator_spaceship.md

Documentation change (#3672)

2022-08-05 19:51:39 +02:00

operator_value_t.md

Reorganize directories (#3462)

2022-05-01 09:41:50 +02:00

operator_ValueType.md

📝 add more docs (#5231)

2026-07-04 11:13:25 +02:00

operator[].md

Throw std::length_error for operator[](SIZE_MAX) instead of corrupting the array (#5687)

2026-09-30 20:07:06 +02:00

operator+=.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

operator=.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

other_error.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

out_of_range.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

parse_error.md

Add BON8 support (#2998)

2026-09-27 16:56:21 +02:00

parse_event_t.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

parse.md

Fix std::terminate and null pointer access in input_stream_adapter (#5699)

2026-09-30 20:07:33 +02:00

parser_callback_t.md

docs: document how discarded values are removed by the parser callback (#5354)

2026-08-04 08:45:02 +02:00

patch_inplace.md

Reject JSON Patch move when from is a proper prefix of path (#5497)

2026-09-09 09:49:12 +02:00

patch.md

Reject JSON Patch move when from is a proper prefix of path (#5497)

2026-09-09 09:49:12 +02:00

push_back.md

📝 add more docs (#5231)

2026-07-04 11:13:25 +02:00

rbegin.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

rend.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

sax_parse.md

Add BON8 support (#2998)

2026-09-27 16:56:21 +02:00

size.md

Reorganize directories (#3462)

2022-05-01 09:41:50 +02:00

start_pos.md

Clean up and document project files (#4560)

2025-01-17 06:53:35 +01:00

std_formatter.md

Documentation review (#5257)

2026-07-09 17:24:19 +02:00

std_hash.md

Adjust JSON Pointer examples (#3622)

2022-07-29 14:28:37 +02:00

std_swap.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

string_t.md

Support custom object/array types and improve template parameter handling (#5443)

2026-09-15 20:46:37 +02:00

swap.md

Exchange the CustomBaseClass subobject in basic_json::swap() (#5697)

2026-09-30 20:07:24 +02:00

to_bjdata.md

Add BON8 support (#2998)

2026-09-27 16:56:21 +02:00

to_bon8.md

Add BON8 support (#2998)

2026-09-27 16:56:21 +02:00

to_bson.md

Move to_bson's binary subtype check into calc_bson_sizes (#5703)

2026-09-30 20:07:41 +02:00

to_cbor.md

Add BON8 support (#2998)

2026-09-27 16:56:21 +02:00

to_msgpack.md

Fix to_msgpack() reading the inactive number union member (#5694)

2026-09-30 20:07:19 +02:00

to_string.md

📝 add more docs (#5231)

2026-07-04 11:13:25 +02:00

to_ubjson.md

Add BON8 support (#2998)

2026-09-27 16:56:21 +02:00

type_error.md

📝 fix docs (#5217)

2026-06-29 22:15:18 +02:00

type_name.md

Documentation review (#5257)

2026-07-09 17:24:19 +02:00

type.md

Reorganize directories (#3462)

2022-05-01 09:41:50 +02:00

unflatten.md

Support custom object/array types and improve template parameter handling (#5443)

2026-09-15 20:46:37 +02:00

update.md

📝 add more docs (#5231)

2026-07-04 11:13:25 +02:00

value_t.md

Documentation change (#3672)

2022-08-05 19:51:39 +02:00

value.md

Reject integral keys for contains(), find(), and count() at compile time (#5705)

2026-09-30 20:07:45 +02:00