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Niels Lohmann
fc7fde6910
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>