#### async_immediate (2 of 2 overloads)

Launch a trivial asynchronous operation that completes immediately.

    template<
        typename ExecutionContext,
        typename NullaryToken = default_completion_token_t<typename ExecutionContext::executor_type>>
    DEDUCED async_immediate(
        ExecutionContext & ctx,
        NullaryToken && token = default_completion_token_t< typename ExecutionContext::executor_type >(),
        constraint_t< is_convertible< ExecutionContext &, execution_context & >::value >  = 0);

The async_immediate function is intended for use by composed operations, which can delegate to this operation in order to implement the correct semantics for immediate completion.

###### Parameters

ex

  The execution context used to obtain the asynchronous operation's I/O executor.

token

  The completion token.

The completion handler is immediately submitted for execution by calling `dispatch` on the handler's associated immediate executor.

If the completion handler does not have a customised associated immediate executor, then the handler is submitted as if by calling `post` on the I/O executor obtained from the supplied execution context.

###### Completion Signature

    void()