shared_ptr's reference counter thread safety on ARM Cortex-M

[Jonathan Wakely]

On 19 February 2018 at 15:37, Oleg Endo wrote:
> Even though on such systems there might not be real threads, atomic
> operations can still be useful, e.g. when sharing variables between the
> "main thread" and interrupt handlers (adhoc preemptive threads so to
> say).

It would be fairly simple to add a new mode that means libstdc++
should use atomic ops, but not provide <thread>, <mutex> etc.

Somebody who cares about it just needs to do the work.