<flat_set>: Make flat_(multi)set insertion exception-safe for non-standard sequence containers
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<flat_set>: Make flat_(multi)set` insertion exception-safe for non-standard sequence containers<flat_set>: Make flat_(multi)set insertion exception-safe for non-standard sequence containers
…ence containers Per N5032 [container.reqmts]/66.1, exception safety of single element insertion is only guaranteed for standard containers. So perhaps we should guard the insertion for non-standard containers that do not have guaranteed (exception-safe) `emplace`. The `emplace` calls are only guarded for containers whose `emplace` have no guaranteed exception safety. Currently, all supported standard containers have such exception safety, so this only affects non-standard containers.
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AlexGuteniev
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Dec 22, 2025
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Per N5032 [container.reqmts]/66.1, exception safety of single element insertion is only guaranteed for standard containers. So perhaps we should guard the insertion for non-standard containers that do not have guaranteed (exception-safe)
emplace.The
emplacecalls are only guarded for containers whoseemplacehave no guaranteed exception safety. Currently, all supported standard containers have such exception safety, so this only affects non-standard containers.Unblocked libcxx tests:
std/containers/container.adaptors/flat.set/flat.set.modifiers/emplace_hint.pass.cppstd/containers/container.adaptors/flat.set/flat.set.modifiers/emplace.pass.cppstd/containers/container.adaptors/flat.set/flat.set.modifiers/insert_cv.pass.cppstd/containers/container.adaptors/flat.set/flat.set.modifiers/insert_iter_cv.pass.cppstd/containers/container.adaptors/flat.set/flat.set.modifiers/insert_iter_rv.pass.cppstd/containers/container.adaptors/flat.set/flat.set.modifiers/insert_rv.pass.cppstd/containers/container.adaptors/flat.set/flat.set.modifiers/insert_transparent.pass.cpp(for Clang only, due to MSVC not implementing WG21-P2448R2)Fixes #5538.