connect (9 of 12 overloads)

(Deprecated: Use range overload.) Establishes a socket connection by trying each endpoint in a sequence.

template<
    typename Protocol,
    typename Executor,
    typename Iterator,
    typename ConnectCondition>
Iterator connect(
    basic_socket< Protocol, Executor > & s,
    Iterator begin,
    ConnectCondition connect_condition,
    constraint_t<!is_endpoint_sequence< Iterator >::value >  = 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 connect member function, once for each endpoint in the sequence, until a connection is successfully established.

Parameters

s

The socket to be connected. If the socket is already open, it will be closed.

begin

An iterator pointing to the start of a sequence of endpoints.

connect_condition

A function object that is called prior to each connection attempt. The signature of the function object must be:

bool connect_condition(
   const asio::error_code& ec,
   const typename Protocol::endpoint& next);

The ec parameter contains the result from the most recent connect operation. Before the first connection attempt, ec is always set to indicate success. The next 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.

Return Value

On success, an iterator denoting the successfully connected endpoint. Otherwise, the end iterator.

Exceptions

asio::system_error: Thrown on failure. If the sequence is empty, the associated error_code is asio::error::not_found. Otherwise, contains the error from the last connection attempt.

Remarks

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 asio::ip::tcp::resolver::iterator.