https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99692
--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Sergey Kaniskin from comment #3) > I was unsure whether to file it under compiler or stdlibc++ as it’s accepted > by another compilers using stdlibc++. There's no such component, it's libstdc++. But if the same libstdc++ code works with other compilers then it's probably not a libstdc++ bug. The __rvalue_ostream_type constraints are going away soon: https://gcc.gnu.org/pipermail/gcc-patches/2021-March/566863.html
