basic_raw_socket::async_send (1 of 2 overloads)

Start an asynchronous send on a connected socket.

template<
    typename ConstBufferSequence,
    typename WriteHandler>
DEDUCED async_send(
    const ConstBufferSequence & buffers,
    WriteHandler && handler);

This function is used to send data on the raw socket. The function call will block until the data has been sent successfully or an error occurs.

Parameters

buffers

One or more data buffers to be sent on the socket. Although the buffers object may be copied as necessary, ownership of the underlying memory blocks is retained by the caller, which must guarantee that they remain valid until the handler is called.

handler

The handler to be called when the send operation completes. Copies will be made of the handler as required. The function signature of the handler must be:

void handler(
  const asio::error_code& error, // Result of operation.
  std::size_t bytes_transferred           // Number of bytes sent.
);

Regardless of whether the asynchronous operation completes immediately or not, the handler will not be invoked from within this function. Invocation of the handler will be performed in a manner equivalent to using asio::io_context::post().

Remarks

The async_send operation can only be used with a connected socket. Use the async_send_to function to send data on an unconnected raw socket.

Example

To send a single data buffer use the buffer function as follows:

socket.async_send(asio::buffer(data, size), handler);

See the buffer documentation for information on sending multiple buffers in one go, and how to use it with arrays, boost::array or std::vector.