* Thomas Rodgers:
> + static __gthread_t
> + _S_get_tid() noexcept
> + {
> +#ifdef __GLIBC__
> + // For the GNU C library pthread_self() is usable without linking to
> + // libpthread.so but returns 0, so we cannot use it in single-threaded
> + // programs, because this_thread::get_id() != thread::id{} must be true.
> + // We know that pthread_t is an integral type in the GNU C library.
> + if (!__gthread_active_p())
> + return 1;
> +#endif
> + return __gthread_self();
> + }
This comment seems outdated or incomplete. pthread_self returns a
proper pointer since glibc 2.27, I believe.
I'm also not sure how the difference is observable for the libstdc++
implementation. Late loading of libpthread isn't quite supported.
