cpp/thread/jthread/request stop

Issues a stop request to the internal stop-state, if it has not yet already had stop requested.

The determination is made atomically, and if stop was requested, the stop-state is atomically updated to avoid race conditions, such that: However, see the Notes section.
 * and can be concurrently invoked on other stds and stds of the same shared stop-state
 * can be concurrently invoked from multiple threads on the same object or on other std objects associated with the same stop-state, and only one will actually perform the stop request

Parameters
(none)

Return value
if this invocation made a stop request, otherwise

Postconditions
For a std retrieved by or a std retrieved by,  is.