...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 receive.
template< typename MutableBufferSequence, typename ReadHandler = DEFAULT> DEDUCED async_receive_from( const MutableBufferSequence & buffers, endpoint_type & sender_endpoint, ReadHandler && handler = DEFAULT);
This function is used to asynchronously receive a datagram. The function call always returns immediately.
One or more buffers into which the data will be received. 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.
An endpoint object that receives the endpoint of the remote sender of the datagram. Ownership of the sender_endpoint object is retained by the caller, which must guarantee that it is valid until the handler is called.
The handler to be called when the receive operation completes. Copies will be made of the handler as required. The function signature of the handler must be:
void handler( const boost::system::error_code& error, // Result of operation. std::size_t bytes_transferred // Number of bytes received. );
Regardless of whether the asynchronous operation completes immediately
or not, the 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 post
.
To receive into a single data buffer use the buffer
function as follows:
socket.async_receive_from( boost::asio::buffer(data, size), sender_endpoint, handler);
See the buffer
documentation for information on receiving into multiple buffers in one
go, and how to use it with arrays, boost::array or std::vector.