...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Cancels one asynchronous operation that is waiting on the timer.
std::size_t cancel_one();
This function forces the completion of one pending asynchronous wait
operation against the timer. Handlers are cancelled in FIFO order. The
handler for the cancelled operation will be invoked with the boost::asio::error::operation_aborted
error code.
Cancelling the timer does not change the expiry time.
The number of asynchronous operations that were cancelled. That is, either 0 or 1.
Thrown on failure.
If the timer has already expired when cancel_one()
is called, then the handlers for asynchronous
wait operations will:
These handlers can no longer be cancelled, and therefore are passed an error code that indicates the successful completion of the wait operation.