Start an asynchronous SSL handshake.
template< typename ConstBufferSequence, typename BufferedHandshakeHandler = DEFAULT> DEDUCED async_handshake( handshake_type type, const ConstBufferSequence & buffers, BufferedHandshakeHandler && handler = DEFAULT);
This function is used to asynchronously perform an SSL handshake on the stream. This function call always returns immediately.
The type of handshaking to be performed, i.e. as a client or as a server.
The buffered data to be reused for the handshake. Although the buffers object may be copied as necessary, ownership of the underlying buffers is retained by the caller, which must guarantee that they remain valid until the handler is called.
The handler to be called when the handshake operation completes. Copies will be made of the handler as required. The equivalent function signature of the handler must be:
void handler( const boost::system::error_code& error, // Result of operation. std::size_t bytes_transferred // Amount of buffers used in handshake. );