https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90192
--- Comment #7 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Tomasz Kaminski <tkami...@gcc.gnu.org>: https://gcc.gnu.org/g:390f3a690cf5c6bc8f7290484cafa6617c1757d4 commit r16-3399-g390f3a690cf5c6bc8f7290484cafa6617c1757d4 Author: Tomasz KamiÅski <tkami...@redhat.com> Date: Mon Aug 25 13:15:35 2025 +0200 libstdc++: Do not require assignment for vector::resize(n, v) [PR90192] This patch introduces a new function, _M_fill_append, which is invoked when copies of the same value are appended to the end of a vector. Unlike _M_fill_insert(end(), n, v), _M_fill_append never permute elements in place, so it does not require: * vector element type to be assignable; * a copy of the inserted value, in the case where it points to an element of the vector. vector::resize(n, v) now uses _M_fill_append, fixing the non-conformance where element types were required to be assignable. In addition, _M_fill_insert(end(), n, v) now delegates to _M_fill_append, which eliminates an unnecessary copy of v when the existing capacity is used. PR libstdc++/90192 libstdc++-v3/ChangeLog: * include/bits/stl_vector.h (vector<T>::_M_fill_append): Declare. (vector<T>::fill): Use _M_fill_append instead of _M_fill_insert. * include/bits/vector.tcc (vector<T>::_M_fill_append): Define (vector<T>::_M_fill_insert): Delegate to _M_fill_append when elements are appended. * testsuite/23_containers/vector/modifiers/moveable.cc: Updated copycount for inserting at the end (appending). * testsuite/23_containers/vector/modifiers/resize.cc: New test. * testsuite/backward/hash_set/check_construct_destroy.cc: Updated copycount, the hash_set constructor uses insert to fill buckets with nullptrs. Reviewed-by: Jonathan Wakely <jwak...@redhat.com> Signed-off-by: Tomasz KamiÅski <tkami...@redhat.com>
