On Thu, 14 Dec 2023, Thomas Rodgers wrote:
I need to look at this a bit more (and not on my phone, at lunch). Ultimately, C++26 expects to add predicate waits and returning a ‘tri-state’ result isn’t something that’s been considered or likely to be approved.
Ok, then that seems to fit best with my second suggestion: the predicate should only test the value and do nothing else, and actually trying to decrement the semaphore is left up to the caller _M_acquire(), which must then retry __atomic_wait_address if the compare-exchange fails.
-- Nate Eldredge n...@thatsmathematics.com
