https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101055
--- 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:c4f1bbed3d0184955d39adf0be287667891baf83 commit r11-8567-gc4f1bbed3d0184955d39adf0be287667891baf83 Author: Jonathan Wakely <jwak...@redhat.com> Date: Mon Jun 14 10:58:15 2021 +0100 libstdc++: Use reserved name for attribute [PR101055] The no_unique_address attribute is not a reserved name until C++20, so to use it in C++11/14/17 modes we should use the __no_unique_address_ form. We already use that form when using the attribute, but not in the __has_cpp_attribute check. libstdc++-v3/ChangeLog: PR libstdc++/101055 * include/std/tuple: Use reserved form of attribute name. * testsuite/17_intro/headers/c++2011/all_attributes.cc: Add check for no_unique_address. * testsuite/17_intro/headers/c++2014/all_attributes.cc: Likewise. * testsuite/17_intro/headers/c++2017/all_attributes.cc: Likewise. (cherry picked from commit 917efba2dd4ff34336d0d3aa55285ae22503e4aa)