https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103549
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-11 branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:5e0ef5621b518caa593b77b7c8f202ee018a0900 commit r11-9437-g5e0ef5621b518caa593b77b7c8f202ee018a0900 Author: Jonathan Wakely <jwak...@redhat.com> Date: Sat Dec 4 11:38:25 2021 +0000 libstdc++: Initialize member in std::match_results [PR103549] This fixes a -Wuninitialized warning for std::cmatch m1, m2; m1=m2; Also name the template parameters in the forward declaration, to get rid of the <template-parameter-1-1> noise in diagnostics. libstdc++-v3/ChangeLog: PR libstdc++/103549 * include/bits/regex.h (match_results): Give names to template parameters in first declaration. (match_results::_M_begin): Add default member-initializer. (cherry picked from commit 87710ec7b213245ecb194b778e97ae3a6790394f)