* docs: qualify the operator>> stream positioning guarantee
operator>>'s notes state that it leaves the stream positioned right
after the parsed value, so that concatenated JSON values can be read
back to back. That does not hold when the value is a number: a number
is only terminated by the character that follows it, and the lexer's
unget() is simulated (it rewinds only the lexer's own bookkeeping),
so that character stays consumed from the stream.
Document the actual behaviour: the guarantee holds for all value types
except numbers, which must be followed by whitespace. Also qualify the
cross-reference on the JSON Lines page, which repeated the unqualified
claim.
Documentation only; the behaviour itself is tracked in #5340.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* fix: restore the character that terminates a number (#5340)
operator>> is documented to leave the stream positioned right after the
parsed value, so that concatenated JSON values can be read back to back.
That did not hold for numbers: a number is only terminated by the
character following it, and lexer::scan_number() reads that character
and calls unget() -- which is simulated and rewinds only the lexer's own
bookkeeping. input_stream_adapter consumes via sbumpc() with no matching
sungetc(), so the terminating character stayed consumed and the next
extraction started one byte too late ('1true' left the stream at 'rue').
Propagating unget() to the adapter directly does not work: next_unget
makes the following get() replay the cached character, so the terminator
would be delivered twice. Instead, restore the still-pending character
once at the end of a non-strict parse, where the input is handed back to
the caller:
- input_stream_adapter gains unget_character() (sungetc()) and advertises
it via supports_unget, detected the same way as supports_seek.
- lexer::restore_pending_unget() turns a pending simulated unget of a
real (non-EOF) character into a real one and clears next_unget so the
character is not also replayed. It is a no-op for adapters that cannot
unget, and reports failure when sungetc() fails, in which case the
input is left as it was before.
- parser calls it on the three non-strict paths, i.e. for operator>> and
sax_parse(strict = false).
Strict parse()/accept() are unaffected: they require the input to end
after the value, so the character is consumed by the end-of-input check
anyway. Parse error messages and reported positions are unchanged.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* tests: fix CI failures in the #5340 test helpers
Four CI failures, all in the new test code:
- GCC (-Werror=useless-cast): drop the `json(...)` wrapper around
`json::parse(...)`, which already returns a `json`.
- GCC (-Werror=unused-result): assign the discarded `json::parse()`
result to a dummy, the idiom used elsewhere in the test suite, and
catch `json::parse_error&` for consistency.
- clang-tidy (google-default-arguments): remove the default argument
from the `pbackfail()` override; `sungetc()` supplies the base
declaration's default.
- MSVC (bad allocation): `no_putback_streambuf::underflow()` set a
one-character get area without advancing `m_pos`, so an implementation
whose `istream::get` peeks before it bumps re-read the same character
forever. Keep no get area at all: `underflow()` peeks, `uflow()`
consumes, and `sungetc()` still always lands in `pbackfail()`, which
is what the test needs.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* fix: leave the character that terminates a number in the input
Read the character following a number without consuming it, instead of
consuming it and putting it back. input_stream_adapter now peeks with
sgetc() and only steps over the character when the next one is requested
or when the adapter is destroyed, so releasing it cannot fail - no
putback position is required from the streambuf.
Suggested by gregmarr in #5344.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* docs: match the version history wording to the peek-based fix
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* docs: drop the whitespace-separator caveat from the parsing pages
The caveat added in #5343 describes the behavior this branch fixes: a
number no longer consumes the character that terminates it, so
concatenated values need no separator.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* refactor: split the strict and non-strict paths in parser
Folding the release_lookahead() call into the existing strict check left
the "in strict mode" comment on an else-if branch, and made the strict
condition in sax_parse() redundant with the branch it followed.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Put the stream position fix behind JSON_PRECISE_STREAM_POSITION
Leaving the character that terminates a number in the stream is observable:
reading "1,2,3" with repeated operator>> works today only because the comma
after each number is swallowed, and std::getline after a number skips the
line break. Both break with the fix, so make it opt-in for 3.x, as suggested
by @gregmarr in the review.
- JSON_PRECISE_STREAM_POSITION (default 0) selects the peek-based
input_stream_adapter. Without it, the adapter is the consuming one from
develop and has no supports_lookahead, so lexer::release_lookahead() and
the parser's calls to it compile to nothing.
- The macro changes input_stream_adapter's layout and member functions, so
it gets the ABI tag _psp, after _bics. The ABI config tests, the natvis
generator, and nlohmann_json.natvis (regenerated) know the tag.
- The tests for the fix move to unit-precise-stream-position.cpp, which
defines the macro itself and runs in every build, and gain the two cases
above. unit-deserialization.cpp pins the default behavior instead.
- The docs describe the default behavior again and point to the new macro
page; version history says "added in 3.13.0, planned default in 4.0.0".
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---------
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* 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 container input_adapter SFINAE for lvalue-only ADL begin/end (#111)
The container overload of json::parse(c) / accept(c) / sax_parse(c, ...)
silently dropped from overload resolution for user types whose ADL
begin(T&) / end(T&) accepted only non-const lvalue references
(a legitimate pattern matching std::begin semantics). This was because
the detection code used std::declval<ContainerType>() which synthesized
an rvalue, and the rvalue failed to bind to lvalue-only ADL functions.
Fix by making both the outer input_adapter(ContainerType&&) and the
factory's create(ContainerType&&) forwarding references, preserving the
caller's value category and constness via reference collapsing. This
ensures detection (std::declval) and actual use (std::forward) always
match without needing decay/remove_reference.
- Rewrite input_adapters.hpp container overload with forwarding refs
- Add regression tests for lvalue-only non-const ADL begin/end
- Add regression test for rvalue containers (no breakage)
- Update API docs (parse, accept, sax_parse, from_*) to clarify
that begin/end must match std::begin/std::end semantics
- Add version history notes for 3.13.0
- Regenerate amalgamation
Second-order effect: binary_reader.hpp's internal call to
input_adapter(number_vector) now deduces iterator vs const_iterator
based on the lvalue; functionally harmless (iterator_input_adapter is
iterator-type-agnostic), verified via unit-ubjson/unit-bjdata tests.
Closes remaining limitation from #4354 / PR #5218 (todo 106).
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Avoid strlen() in test container to fix Codacy CWE-126 flag
Suppressing the strlen()-based CWE-126 warning with NOLINT/nosec
comments only silenced clang-tidy and the standalone Flawfinder
Action; Codacy's own analysis (which also flags this pattern and
doesn't honor those suppression comments) still reported it as a new
issue, plus flagged the near-duplicate begin/end pair as cloned code.
Store the buffer's size explicitly in MyContainerNonConstADL instead
of computing it via strlen() in end(), which removes the flagged
pattern outright and also de-duplicates the struct from the existing
MyContainer's char*-based begin/end pair.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Avoid trailing return type to satisfy clang-tidy fuchsia-trailing-return
The forwarding-reference input_adapter(ContainerType&&) entry point was
written with an auto/trailing-decltype return type, but this project's
ci_clang_tidy job enables the fuchsia-trailing-return check as an
error, which rejects it. The return type only depends on the template
parameter ContainerType, not on the runtime parameter, so it can be
written as an ordinary leading return type instead - no functional
change.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Avoid C-style array in test to satisfy clang-tidy avoid-c-arrays
clang-tidy's cppcoreguidelines/hicpp/modernize-avoid-c-arrays checks
flagged the char raw_data[] declaration used to reproduce the
lvalue-only non-const ADL begin/end scenario. Use std::string instead
and take a mutable pointer via &raw_data[0], which is the standard
way to get a non-const char* into a string's buffer under C++11
(std::string::data() only returns non-const in C++17 and later).
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---------
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* 📝 Fix documentation gaps for 3.13.0 release (todos 138-142)
- Todo 138: Add "Known issues" section to modules.md with compiler-specific troubleshooting (GCC redefinition, MSVC symbol export). Add pointer note to quality_assurance.md.
- Todo 139: Document CBOR/MessagePack half-precision float encoding for NaN/Infinity (0xF9/0xCA with exact byte sequences). Explain pre-3.13.0 double-precision bug mechanism without issue citations.
- Todo 140: Document CBOR negative-integer-overflow rejection (parse_error.112) for magnitudes exceeding int64_t range (already implemented in rev 1).
- Todo 141: Update version history in value.md and operator[].md with behavior-change details, removing issue citations per citation policy (prose is self-contained).
- Todo 142: Global sed replace of 3.12.x → 3.13.0 placeholder across all 20 documentation files.
Revision 2 incorporates feedback to reduce changelog-like issue citations. Only citations that add unique troubleshooting value are retained (#5103 for GCC workaround, #3970 for MSVC symbol export). "Known issues" section follows PR #5252's visual pattern (info admonition with bold-bullet format).
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* 📝 Document integer type selection, type_name() invalid value, and std::optional get() fix
- number_handling.md: clarify that positive/negative integers select
unsigned/signed storage based on the leading minus sign (todo 143).
- type_name.md: document the new "invalid" return value for corrupted
JSON values (todo 145).
- get.md: note that get<std::optional<T>>() was unreachable in every
configuration prior to 3.13.0 due to an internal macro-guard bug,
unrelated to JSON_USE_IMPLICIT_CONVERSIONS's actual effect (todo 144).
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---------
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Niels Lohmann
chirszandNiels Lohmann