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>
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>
Niels LohmannandClaude Opus 5