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### experimental::use_coro_t

A completion token that creates another coro for the task completion.

    template<
        typename Allocator = std::allocator<void>>
    struct use_coro_t

##### Types

Name | Description
--- | ---
allocator_type | The allocator type. The allocator is used when constructing the std::promise object for a given asynchronous operation.
as_default_on_t | Type alias to adapt an I/O object to use use_coro_t as its default completion token type.
executor_with_default | Adapts an executor to add the use_coro_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_coro_t as its default completion token type.
get_allocator | Obtain allocator.
rebind | Specify an alternate allocator.
use_coro_t [constructor] | Default constructor. — Constructor used to specify file name, line, and function name.

The `use_coro_t` class, with its value `use_coro`, is used to represent an operation that can be awaited by the current resumable coroutine. This completion token may be passed as a handler to an asynchronous operation. For example:

    coro<void> my_coroutine(tcp::socket my_socket)
    {
      std::size_t n = co_await my_socket.async_read_some(buffer, use_coro);
      ...
    }

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.

Note that this token is not the most efficient (use the default completion token `boost::asio::deferred` for that) but does provide type erasure, as it will always return a `coro`.

##### Requirements

Header: `boost/asio/experimental/use_coro.hpp`

Convenience header: None