...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 ReadToken = default_completion_token_t<executor_type>> DEDUCED async_receive( const MutableBufferSequence & buffers, socket_base::message_flags in_flags, socket_base::message_flags & out_flags, ReadToken && token = default_completion_token_t< executor_type >());
This function is used to asynchronously receive data from the sequenced data socket. It is an initiating function for an asynchronous operation, and 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 completion handler is called.
Flags specifying how the receive call is to be made.
Once the asynchronous operation completes, contains flags associated
with the received data. For example, if the socket_base::message_end_of_record
bit is set then the received data marks the end of a record. The
caller must guarantee that the referenced variable remains valid
until the completion handler is called.
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 bytes_transferred // Number of bytes 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
.
void(boost::system::error_code, std::size_t)
To receive into a single data buffer use the buffer
function as follows:
socket.async_receive( boost::asio::buffer(data, size), 0, out_flags, 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.
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