32 Concurrency support library [thread]

32.3 Stop tokens [thread.stoptoken]

32.3.6 Class template stop_callback [stopcallback]

32.3.6.2 Constructors and destructor [stopcallback.cons]

template<class Initializer> explicit stop_callback(const stop_token& st, Initializer&& init) noexcept(is_nothrow_constructible_v<CallbackFn, Initializer>); template<class Initializer> explicit stop_callback(stop_token&& st, Initializer&& init) noexcept(is_nothrow_constructible_v<CallbackFn, Initializer>);
Constraints: CallbackFn and Initializer satisfy constructible_from<CallbackFn, Initializer>.
Effects: Initializes callback-fn with std​::​forward<Initializer>(init) and executes a stoppable callback registration ([stoptoken.concepts]).
If a callback is registered with st's shared stop state, then *this acquires shared ownership of that stop state.
~stop_callback();
Effects: Executes a stoppable callback deregistration ([stoptoken.concepts]) and releases ownership of the stop state, if any.