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std::latch:: count_down

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std::latch
void count_down ( std:: ptrdiff_t n = 1 ) ;
(since C++20)

Atomically decrements the internal counter by n without blocking the caller.

If n is greater than the value of the internal counter or is negative, the behavior is undefined.

This operation strongly happens-before all calls that are unblocked on this latch .

Parameters

n - the value by which the internal counter is decreased

Return value

(none)

Exceptions

Throws std::system_error with an error code allowed for mutex types on error.