Splitting removed-key detection and common-key recursion into separate
passes (for the earlier lookup-count fix) changed the emitted patch's
op order: all "remove" ops now came before all recursive per-key diffs,
instead of interleaved in source's iteration order as the original
implementation did. This broke docs/mkdocs/docs/examples/diff.output's
exact-match CI check (ci_test_examples) even though the patch was still
semantically correct.
Defer "remove" emission into the same walk that does the recursive
diffs, so common keys and deleted keys are interleaved in source order
again, matching historical output.
While restructuring that walk, the reordering ("slow path") branch was
only emitting "remove" for keys common to both objects, never for keys
present in source but genuinely absent from target -- a key deleted
alongside an actual reorder would silently survive the patch. Fixed by
removing every source key in the slow path (both deleted and common
keys need removing there; common keys are then re-added in target's
order). Verified with a targeted reorder+deletion case and a fresh
20,000-case round-trip fuzz run (0 failures).
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
The previous fix for ordered_json member order re-derived common-key
order and suffix information with extra target.find()/source.find()
calls layered on top of the pre-existing removed/added-key passes,
instead of reusing those same passes. This roughly tripled the number
of map lookups per diff() call for every object, including plain
`json`, where the reordering path is never taken.
Piggyback the order tracking (and the "add" op construction for new
keys) onto the two passes the algorithm already needs to detect
removed/added keys, and walk the fast path's recursion in lockstep
with the precomputed common-key list instead of re-querying `target`.
This restores diff() to its pre-existing lookup count; benchmarked at
n=1000 keys, ordered_json::diff() was roughly 2x slower than baseline
before this change and is back within noise of baseline after it.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
diff() compared source/target objects purely by key set, ignoring
relative member order. For ordered_json (insertion-ordered, vector-
backed object_t), two objects that differ only in member order are
unequal via operator==, but diff() never emitted any patch operation
to fix the order, so source.patch(diff(source, target)) == target
could fail to hold.
Fix by detecting when common keys appear in a different relative
order in source vs. target (or when a new key would need to land
somewhere other than the end), and in that case removing and
re-adding the affected keys in target's order, which relies on
patch()'s "add" op appending new keys at the end of an ordered_map.
For plain json (std::map-backed, always key-sorted iteration) this
is a no-op and the original minimal per-key diff path is unchanged.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Both overloads swapped the underlying container storage but never called
set_parents(), leaving elements moved into *this with stale m_parent
pointers (typically nullptr from the free-standing array_t/object_t).
This produced wrong JSON Pointer paths in diagnostic messages and could
trip assert_invariant() on subsequent copies. Mirrors the fix already
applied in swap(reference other).
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
The mixed number arms of JSON_IMPLEMENT_OPERATOR cast the integer to
number_float_t before comparing. Past the float's mantissa that cast is lossy:
2^63-2 and 2^63-1 both round to 2^63, so each compares equal to that float
while differing from each other. Equality is therefore intransitive and the
ordering is not a strict weak ordering, which makes std::sort over such values,
or using them as keys in std::set or std::map, undefined behavior.
Compare the two exactly instead. The integer's range is a power of two the
float represents exactly, so a float outside it is ordered by magnitude alone;
inside it, truncating the float is exact, and the integer parts and then any
fractional part decide. The helper hands back a pair whose comparison with the
original operator reproduces that ordering, which keeps every operator's return
type as it was, including partial_ordering for the spaceship.
A NaN operand is returned in both members, so NaN stays false for the
relational operators and unordered for <=>. Values a float represents exactly
still compare equal, so json(1) == json(1.0) is unchanged.
Signed-off-by: qatcod <79017227+qatcod@users.noreply.github.com>
When merge_objects is true, recurse only if the existing value is an
object. Otherwise overwrite, matching the documented "all other values
are overwritten as usual" behavior.
Fixes#5402
Signed-off-by: elix3r <157088510+22elix3r@users.noreply.github.com>
* Add iterator+sentinel tests and docs for binary deserializers
This commit extends the C++20 ranges support (iterator+sentinel pairs) to the
binary format deserializers from_cbor, from_msgpack, from_ubjson, from_bjdata,
and from_bson, matching what was already done for parse(), accept(), and
sax_parse().
Changes:
- Add istreambuf_sentinel helper to test_utils.hpp for EOF detection in tests
- Add 5 new test cases that read binary files directly via
std::istreambuf_iterator<char> + sentinel, without pre-buffering
- Update documentation for all 5 from_* functions to document overload (3)
with SentinelType parameter
- All tests pass; verified against existing test suite data
- Fix potential buffer over-read warning in heterogeneous iterator test
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Merge iterator+sentinel overloads and fix ambiguity/CI issues
Address PR review feedback and CI failures:
- Merge the separate same-type and sentinel-type iterator overloads of
parse(), accept(), sax_parse(), and the five from_* binary deserializers
into a single overload with SentinelType defaulted to IteratorType,
as suggested in review. Applied the same simplification to the
detail::input_adapter() free functions.
- Fix a latent ambiguity: some compilers (e.g. GCC 4.8) unreliably SFINAE
the operator!= detection for std::nullptr_t against container/string
types, making calls like parse(s, nullptr, ...) ambiguous with the
compatible-input overload. can_compare_ne now explicitly excludes
std::nullptr_t as a SentinelType.
- Use a named enable_if_t template parameter instead of an unnamed
function parameter for the SFINAE guard, fixing a clang-tidy
hicpp-named-parameter/readability-named-parameter failure.
- Update parse.md, accept.md, sax_parse.md, and the five from_*.md pages
to document the merged overload instead of separate (2)/(3) overloads,
also fixing an over-160-char line that broke the documentation
style_check CI job.
- Rework the BSON iterator+sentinel test to parse a BSON file already
present in the test suite instead of writing/deleting a temp file.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Fix -Wunneeded-internal-declaration for CustomSentinel in test
CustomSentinel lives in an anonymous namespace (internal linkage), and
the library's parse loop only ever evaluates the iterator-first
direction (it != last), so the reversed-order friend operator!= was
never referenced. Clang's -Weverything flags such unused internal
declarations as an error. Drop the unused overload; the used direction
is enough to satisfy can_compare_ne's either-order detection.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Fix clang-tidy hicpp-named-parameter and misc-const-correctness
- Drop the unused reversed-order operator!= overload from
utils::istreambuf_sentinel (only iterator != sentinel is ever
evaluated) and name the remaining friend's sentinel parameter, fixing
hicpp-named-parameter/readability-named-parameter.
- Mark the istreambuf_iterator first/last helper variable const in the
five binary-format sentinel tests, fixing misc-const-correctness.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Fix clang-tidy misc-const-correctness in heterogeneous sentinel test
json_str is only read via .data()/.size() and never reassigned, so
clang-tidy correctly flags it as const-able. Verified against the exact
CI job (silkeh/clang:dev, ci_clang_tidy target) by running clang-tidy
directly on this file plus the five binary-format sentinel tests
touched by prior commits; all are now clean.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---------
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Fix#3868: Remove operator!= to enable P2468R2 rewritten candidate synthesis
Under C++20 P2468R2, a hand-written operator!= suppresses the compiler's
rewritten-candidate synthesis for operator==, preventing heterogeneous
comparisons like `std::string s; json j; s == j;` from compiling.
Fix by removing the hand-written operator!=, allowing the compiler to
synthesize != as !(a==b) in all language modes (C++20 member functions
and pre-C++20 friend functions).
Behavior change: operator!= now returns !(a==b) unconditionally, including
for special values like NaN and discarded. This means:
- NaN != NaN now returns true (matches IEEE-754 semantics)
- discarded != x now returns true for any x (matches !(discarded == x))
This also fixes underlying defects in previously-working code:
- Restores direct == comparison for views vs json (reverts std::ranges::equal
workaround added in PR #3950 to dodge this bug)
- Re-enables std::string == json comparisons (uncomments check in
unit-constructor1.cpp)
Fixes: #3868, #3979
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* 🚨 fix warning
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---------
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>
When iteration_proxy_value<iter_impl<ordered_json>> appears in a context
that requires it to be complete (function or lambda parameter), the
compiler instantiates basic_json<ordered_map> and walks into
set_parents(iterator, typename iterator::difference_type)
while iterator is still incomplete, failing with "invalid use of
incomplete type".
basic_json::difference_type is already std::ptrdiff_t, so just naming
the underlying type directly avoids the dependent lookup. Behavior and
ABI are unchanged. This was the approach suggested in the issue thread.
Added a regression case in unit-ordered_json.cpp using the same trigger
pattern (lambda parameter naming the proxy type).
Fixes#3732
Signed-off-by: Akhilesh Arora <akhildawra@gmail.com>
* fix: treat single-element brace-init as copy/move
When passing a json value using brace initialization with a single element
(e.g., `json j{someObj}` or `foo({someJson})`), C++ always prefers the
initializer_list constructor over the copy/move constructor. This caused
the value to be unexpectedly wrapped in a single-element array.
This bug was previously compiler-dependent (GCC wrapped, Clang did not),
but Clang 20 started matching GCC behavior, making it a universal issue.
Fix: In the initializer_list constructor, when type deduction is enabled
and the list has exactly one element, copy/move it directly instead of
creating a single-element array.
Before:
json obj = {{"key", 1}};
json j{obj}; // -> [{"key":1}] (wrong: array)
foo({obj}); // -> [{"key":1}] (wrong: array)
After:
json j{obj}; // -> {"key":1} (correct: copy)
foo({obj}); // -> {"key":1} (correct: copy)
To explicitly create a single-element array, use json::array({value}).
Fixes the issue #5074
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* fix: regenerate amalgamated single_include/nlohmann/json.hpp
- Add missing comment from include/nlohmann/json.hpp explaining the
single-element brace-init fix (issue #5074)
- Fix extra 4-space indentation in embedded json_fwd.hpp section
Regenerated by running: make amalgamate
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* Revert brace-init semantics change and fix amalgamation
The single-element brace-init change was a breaking change that cannot be accepted upstream. Reverted all related source, test, and doc changes, then regenerated single_include with correct indentation to pass the amalgamation CI check.
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* Fix: add JSON_BRACE_INIT_COPY_SEMANTICS opt-in macro for issue #5074
Single-element brace initialization wrapping in an array cannot be fixed without breaking existing code. Added JSON_BRACE_INIT_COPY_SEMANTICS as an opt-in macro (default 0) so users can enable copy/move semantics for single-element brace init without affecting anyone relying on the current behavior.
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* docs: add dedicated macro page and CI test target for JSON_BRACE_INIT_COPY_SEMANTICS
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* fix: remove compiler-dependent assertions from #5074 regression test
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* fix: use defined() guard for JSON_BRACE_INIT_COPY_SEMANTICS to satisfy -Wundef
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* docs: fix section name in json_brace_init_copy_semantics.md to pass style check
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
* docs: move Default definition section before Notes to fix style check order
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
---------
Signed-off-by: Samaresh Kumar Singh <ssam3003@gmail.com>
PR #4873 introduced a safety check in sax_parse functions to catch
nullptr passed as SAX parser object, which had been already annotated by
JSON_HEDLEY_NON_NULL macro.
Compilers (e.g. clang) which respected the non-null annotation tended to
eliminate the safety check completely in optimized builds, while
compilers which did not, compiled the safety check in. This led to
different behaviors accross different compilers/platforms and/or build
types (debug, release).
This commit reverts PR #4873 to remove this discrepancy. Passing null to
non-null annotated parameter is considered to be undefined behavior.
Fixes#5048
Signed-off-by: Richard Musil <risa2000x@gmail.com>
Co-authored-by: Richard Musil <risa2000x@gmail.com>
* Add implementation to retrieve start and end positions of json during parse
* Add more unit tests and add start/stop parsing for arrays
* Add raw value for all types
* Add more tests and fix compiler warning
* Amalgamate
* Fix CLang GCC warnings
* Fix error in build
* Style using astyle 3.1
* Fix whitespace changes
* revert
* more whitespace reverts
* Address PR comments
* Fix failing issues
* More whitespace reverts
* Address remaining PR comments
* Address comments
* Switch to using custom base class instead of default basic_json
* Adding a basic using for a json using the new base class. Also address PR comments and fix CI failures
* Address decltype comments
* Diagnostic positions macro (#4)
Co-authored-by: Sush Shringarputale <sushring@linux.microsoft.com>
* Fix missed include deletion
* Add docs and address other PR comments (#5)
* Add docs and address other PR comments
---------
Co-authored-by: Sush Shringarputale <sushring@linux.microsoft.com>
* Address new PR comments and fix CI tests for documentation
* Update documentation based on feedback (#6)
---------
Co-authored-by: Sush Shringarputale <sushring@linux.microsoft.com>
* Address std::size_t and other comments
* Fix new CI issues
* Fix lcov
* Improve lcov case with update to handle_diagnostic_positions call for discarded values
* Fix indentation of LCOV_EXCL_STOP comments
* fix amalgamation astyle issue
---------
Co-authored-by: Sush Shringarputale <sushring@linux.microsoft.com>
Niels Lohmann
Avionic Harshit
Qatadaha Bin Matloob
elix3r
ljcjclljc
Cosmin D.
Swastik Bose
Hariom Phulre
Akhilesh Arora
SamareshSingh
risa2000andRichard Musil
Nikhil
chirszandNiels Lohmann
Nebojša Cvetković
Michael Valladolid
Harinath Nampally
Sushrut ShringarputaleandSush Shringarputale
alferov
tomalakgeretkal