NAME¶

std::stop_callback::stop_callback - std::stop_callback::stop_callback

Synopsis¶

template<class C>
explicit stop_callback( const std::stop_token& st, C&& cb ) (1) (since C++20)
noexcept(/*see below*/);
template<class C>
explicit stop_callback( std::stop_token&& st, C&& cb ) (2) (since C++20)
noexcept(/*see below*/);
stop_callback( const stop_callback& ) = delete; (3) (since C++20)
stop_callback( stop_callback&& ) = delete; (4) (since C++20)

Constructs a new stop_callback object, saving and registering the cb callback
function into the given std::stop_token's associated stop-state, for later
invocation if stop is requested on the associated std::stop_source.

1) Constructs a stop_callback for the given st std::stop_token (copied), with the
given invocable callback function cb.
2) Constructs a stop_callback for the given st std::stop_token (moved), with the
given invocable callback function cb.
3-4) stop_callback is neither CopyConstructible nor MoveConstructible.

Both constructors participate overload resolution only if Callback and C satisfy
constructible_from of std::constructible_from<Callback, C>. If Callback and C
satisfy the concept but fail to satisfy its semantic requirement, the behavior is
undefined.

Parameters¶

st - a std::stop_token object to register this stop_callback object with
cb - the type to invoke if stop is requested

Exceptions¶

1-2)
noexcept specification:
noexcept(std::is_nothrow_constructible_v<Callback, C>)
Any exception thrown by constructor-initializing the given callback into the
stop_callback object.

Notes¶

If st.stop_requested() == true for the passed-in std::stop_token, then the callback
function is invoked in the current thread before the constructor returns.