basic_waitable_timer::async

basic_waitable_timer::async_wait

Start an asynchronous wait on the timer.

template<
    typename WaitHandler = DEFAULT>
DEDUCED async_wait(
    WaitHandler && handler = DEFAULT);

This function may be used to initiate an asynchronous wait against the timer. It always returns immediately.

For each call to async_wait(), the supplied handler will be called exactly once. The handler will be called when:

The timer has expired.
The timer was cancelled, in which case the handler is passed the error code asio::error::operation_aborted.

Parameters

handler

The handler to be called when the timer expires. Copies will be made of the handler as required. The function signature of the handler must be:

void handler(
  const asio::error_code& error // Result of operation.
);

Regardless of whether the asynchronous operation completes immediately or not, the handler will not be invoked from within this function. On immediate completion, invocation of the handler will be performed in a manner equivalent to using post.

Per-Operation Cancellation

This asynchronous operation supports cancellation for the following cancellation_type values:

cancellation_type::terminal
cancellation_type::partial
cancellation_type::total