[PATCH] libstdc++: Diagnose visitors with different return types [PR95904]

[Ville Voutilainen]

On Sat, 10 Oct 2020 at 13:52, Jonathan Wakely <jwakely@redhat.com> wrote:
> index_sequence uses size_t not unsigned long. This parameter pack
> needs to be size_t... _Idxs, and the NTTP for __check_visitor_result
> should be size_t _Idx.

Fixed in https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=02cbd79e4728319e0887ad7783297853b527bb13
after approval-over-irc.