Boost C++ Libraries

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use_awaitable_t

A completion token that represents the currently executing coroutine.

template<
    typename Executor = any_io_executor>
struct use_awaitable_t

Types

Name	Description
as_default_on_t	Type alias to adapt an I/O object to use use_awaitable_t as its default completion token type.
executor_with_default	Adapts an executor to add the use_awaitable_t completion token as the default.

Member Functions

Name	Description
as_default_on [static]	Function helper to adapt an I/O object to use use_awaitable_t as its default completion token type.
use_awaitable_t [constructor]	Default constructor. — Constructor used to specify file name, line, and function name.

The use_awaitable_t class, with its value use_awaitable, is used to represent the currently executing coroutine. This completion token may be passed as a handler to an asynchronous operation. For example:

awaitable<void> my_coroutine()
{
  std::size_t n = co_await my_socket.async_read_some(buffer, use_awaitable);
  ...
}

When used with co_await, the initiating function (async_read_some in the above example) suspends the current coroutine. The coroutine is resumed when the asynchronous operation completes, and the result of the operation is returned.

Requirements

Header: boost/asio/use_awaitable.hpp

Convenience header: boost/asio.hpp