13 Asynchronous model [async]

13.4 Class template async_completion [async.async.completion]

Class template async_completion is provided as a convenience, to simplify the implementation of asynchronous operations that use async_result.

namespace std {
namespace experimental {
namespace net {
inline namespace v1 {

  template<class CompletionToken, class Signature>
  struct async_completion
    using completion_handler_type = async_result<decay_t<CompletionToken>,

    explicit async_completion(CompletionToken& t);
    async_completion(const async_completion&) = delete;
    async_completion& operator=(const async_completion&) = delete;

    see below completion_handler;
    async_result<decay_t<CompletionToken>, Signature> result;

} // inline namespace v1
} // namespace net
} // namespace experimental
} // namespace std

The template parameter Signature shall be a call signature (C++ 2014 [func.def]).

explicit async_completion(CompletionToken& t);

Effects: If CompletionToken and completion_handler_type are the same type, binds completion_handler to t; otherwise, initializes completion_handler with std::forward<CompletionToken>(t). Initializes result with completion_handler.

see below completion_handler;

Type: completion_handler_type& if CompletionToken and completion_handler_type are the same type; otherwise, completion_handler_type.