basic_datagram_socket::async_receive_multiple (3 of 4 overloads)

Start an asynchronous receive of multiple datagrams and their flags.

template<
    typename MutableBufferSequences,
    typename MutableSizeSequence,
    typename MutableFlagsSequence,
    typename ReadMultiToken = default_completion_token_t<executor_type>>
DEDUCED async_receive_multiple(
    MutableBufferSequences && buffer_sequences,
    MutableSizeSequence && sizes,
    MutableFlagsSequence && out_flags,
    ReadMultiToken && token = default_completion_token_t< executor_type >(),
    constraint_t< is_shallow_mutable_sequence< decay_t< MutableFlagsSequence > >::value >  = 0);

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

Parameters

buffer_sequences

A forward range of mutable buffer sequences, one per datagram, into which the data will be received. 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.

sizes

A forward range of std::size_t, one per datagram, into which the number of bytes received in each datagram is written. Although the range object may be copied as necessary, ownership of the underlying elements is retained by the caller, which must guarantee that they remain valid until the completion handler is called.

out_flags

A forward range of socket_base::message_flags, one per datagram, into which the flags associated with each received datagram are written. Although the range object may be copied as necessary, ownership of the underlying elements is retained by the caller, which must guarantee that they remain valid until the completion handler is called.

token

The completion token that will be used to produce a completion handler, which will be called when the receive 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 received.
);

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_receive_multiple operation can only be used with a connected socket. Use the async_receive_from_multiple function to receive 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