...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Start an asynchronous send.
template< typename ConstBufferSequence, typename WriteToken = default_completion_token_t<executor_type>> DEDUCED async_send( const ConstBufferSequence & buffers, socket_base::message_flags flags, WriteToken && token = default_completion_token_t< executor_type >());
This function is used to asynchronously send data on the stream socket. It is an initiating function for an asynchronous operation, and always returns immediately.
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 completion handler is called.
Flags specifying how the send call is to be made.
The completion
token that will be used to produce a completion handler,
which will be called when the send completes. Potential completion
tokens include use_future
, use_awaitable
, yield_context
, or a function
object with the correct completion signature. The function signature
of the completion handler must be:
void handler( const boost::system::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 completion handler will not be invoked from within
this function. On immediate completion, invocation of the handler
will be performed in a manner equivalent to using async_immediate
.
void(boost::system::error_code, std::size_t)
The send operation may not transmit all of the data to the peer. Consider
using the async_write
function if you
need to ensure that all data is written before the asynchronous operation
completes.
To send a single data buffer use the buffer
function as follows:
socket.async_send(boost::asio::buffer(data, size), 0, 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.
On POSIX or Windows operating systems, this asynchronous operation supports
cancellation for the following cancellation_type
values:
cancellation_type::terminal
cancellation_type::partial
cancellation_type::total