basic_datagram_socket::async_send_multiple (2 of 2 overloads)

Start an asynchronous send of multiple datagrams on a connected socket.

template<
    typename ConstBufferSequences,
    typename WriteMultiToken = default_completion_token_t<executor_type>>
DEDUCED async_send_multiple(
    ConstBufferSequences && buffer_sequences,
    socket_base::message_flags flags,
    WriteMultiToken && token = default_completion_token_t< executor_type >());

This function is used to asynchronously send multiple datagrams on a connected datagram socket. It is an initiating function for an asynchronous operation, and always returns immediately. The number of datagrams sent may be less than the length of the range.

Parameters

buffer_sequences

A forward range of buffer sequences, one per datagram to send. Although the range 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

Flags specifying how the send call is to be made.

token

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 messages_transferred // Number of datagrams 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.

Completion Signature

void(boost::system::error_code, std::size_t)

Remarks

The async_send_multiple operation can only be used with a connected socket. Use the async_send_to_multiple function to send data on an unconnected datagram socket.

Per-Operation Cancellation

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