[Bug libstdc++/97876] stop_token header doesn't compile on clang-8 with -std=c++20

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97876

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #12 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #2)
> Changing the _Stop_state_ref default constructor to:
> 
>     _Stop_state_ref() noexcept {}
> 
> allows it to compile. It shouldn't be needed, but I suppose since the
> constructor is already non-trivial (due to the default member initializer
> that is the cause of the error) we could do that.

I've done this on the gcc-10 branch, but not trunk. That means the same problem
will recur with clang-8 and <stop_token> in gcc-11.

However, I've also removed the <memory_resource> dependency from <regex> on
gcc-10 and trunk, and <shared_mutex> already stopped including <stop_token> on
trunk. So there are fewer routes to <stop_token> now.

Now you just need to wait for Ubuntu to update gcc-10 and for GitHub to deploy
that update, which I can't help with.