StreamType concept

StreamType represents the transport protocol type used to transfer stream of bytes.

StreamType should meet the AsyncStream concept.

Note

	Note
Because `boost::beast::websocket::stream<NextLayer>` does not satisfy `AsyncWriteStream`, requirements were relaxed to allow a stream to provide `async_write` operation instead of `async_write_some`. With `ConstBufferSequence` cb and CompletionToken t, `s.async_write(cb, t)` should meet the requirements of an asynchronous operation with the completion signature `void(error_code ec, size_t n)` and should write all the supplied data to the stream.

Because boost::beast::websocket::stream<NextLayer> does not satisfy AsyncWriteStream, requirements were relaxed to allow a stream to provide async_write operation instead of async_write_some.

With ConstBufferSequence cb and CompletionToken t, s.async_write(cb, t) should meet the requirements of an asynchronous operation with the completion signature void(error_code ec, size_t n) and should write all the supplied data to the stream.

It should follow Asio's layered stream model by having a lowest_layer_type member type, and a lowest_layer member function, returing a lowest_layer_type&. The lowest_layer_type should inherit from boost::asio::ip::tcp::socket.

Additionally, it should have an overload of async_shutdown function that is discoverable via argument-dependent lookup (ADL).

The types boost::asio::ip::tcp::socket, boost::asio::ssl::stream<boost::asio::ip::tcp::socket> and boost::beast::websocket::stream<NextLayer> meet these requirements.