(Deprecated: Use range overload.) Asynchronously establishes a socket connection by trying each endpoint in a sequence.
template< typename Protocol, typename Executor, typename Iterator, typename ConnectCondition, typename IteratorConnectToken = DEFAULT> DEDUCED async_connect( basic_socket< Protocol, Executor > & s, Iterator begin, ConnectCondition connect_condition, IteratorConnectToken && token = DEFAULT, typename constraint<!is_endpoint_sequence< Iterator >::value >::type = 0);
This function attempts to connect a socket to one of a sequence of endpoints.
It does this by repeated calls to the socket's
member function, once for each endpoint in the sequence, until a connection
is successfully established. It is an initiating function for an asynchronous operation,
and always returns immediately.
The socket to be connected. If the socket is already open, it will be closed.
An iterator pointing to the start of a sequence of endpoints.
A function object that is called prior to each connection attempt. The signature of the function object must be:
bool connect_condition( const boost::system::error_code& ec, const typename Protocol::endpoint& next);
contains the result from the most recent connect operation. Before
the first connection attempt,
is always set to indicate success. The
parameter is the next endpoint to be tried. The function object should
return true if the next endpoint should be tried, and false if it
should be skipped.
token that will be used to produce a completion handler, which
will be called when the connect completes. Potential completion tokens
yield_context, or a function
object with the correct completion signature. The function signature
of the completion handler must be:
void handler( // Result of operation. if the sequence is empty, set to // boost::asio::error::not_found. Otherwise, contains the // error from the last connection attempt. const boost::system::error_code& error, // On success, an iterator denoting the successfully // connected endpoint. Otherwise, the end iterator. Iterator iterator );
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
This overload assumes that a default constructed object of type
Iterator represents the end of the sequence.
This is a valid assumption for iterator types such as
This asynchronous operation supports cancellation for the following
if they are also supported by the socket's