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Niels Lohmann
100f676b3e
* basic_json, iterators, serializer: remove checks that invariants make dead Branch coverage of the test suite and of 24k mutated inputs showed these conditions as never taken; each is implied by the code around it: - copy_object_level(): `src_it != src_object.cend()`; dst was built from exactly src_object.size() unique keys and src_it advances at most once per member - the general comparison operators (equal_general, less_general, three_way_general): the five same-type scalar cases, which the inline fast path of every operator handles before calling them (now an assert); and the NaN half of compares_unordered() in the mixed-type branch, reached only after all six number pairs returned, where only a discarded operand is unordered - serializer, ensure_ascii: the reset of `bytes` under error_handler_t::keep and the surrogate-pair escape in the UTF8_ACCEPT case; every well-formed multi-byte character is escaped by write_u_escapes() before decode() sees it, so decode() only ever accepts DEL here, a single byte of which nothing was buffered (now asserts) - iter_impl(pointer): the if/else chain assigned value-initialized iterators to the value-initialized m_it No change in behaviour: a build that aborts on each removed side passes the test suite, the fuzz corpora and 23.2M dumps of all 1-, 2- and boundary 4-byte strings in both ensure_ascii modes. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * iter_impl: keep the type-dependent initialization in the constructor The check is not needed for correctness (m_it is value-initialized), but without it GCC 13 generates slower iteration loops: a recursive walk over a parsed document takes 0.5-2.7 % longer (callgrind: +1.9 % instructions on twitter.json, +0.95 % on canada.json). Clang generates identical code either way. See the measurements in #6005. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>