C++2a synchronisation inefficient in GCC 11

[Ville Voutilainen]

On Fri, 26 Feb 2021 at 21:26, Jonathan Wakely via Libstdc++
<libstdc++@gcc.gnu.org> wrote:
> >Oh? That's not a really widely understood fact. I see people using C++20 right
> >now all the time in the cpplang slack and no one seems to be worried that
> >support is experimental.
>
> I can't really help it if people don't read documentation for
> important tools they rely on.
>
> https://gcc.gnu.org/projects/cxx-status.html#cxx20

Also, if it's not a sufficient hint that you need to explicitly tell
the compiler to enter C++20 mode, there's
nothing worth our time to protect such users from the perils of the
world. And trying to remain
ABI-compatible between experimental C++20 support and its subsequent
C++20 support absolutely isn't one
of the things worth our time, even for users that are not idiots. It's
experimental, and We Mean It.