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basic_stream::async_connect (2 of 5 overloads)

Establishes a connection by trying each endpoint in a sequence asynchronously.

    class EndpointSequence,
    class RangeConnectHandler = net::default_completion_token_t<executor_type>>
    EndpointSequence const& endpoints,
    RangeConnectHandler&& handler = net::default_completion_token_t< executor_type >{});

This function attempts to connect the stream to one of a sequence of endpoints by trying each endpoint until a connection is successfully established. The underlying socket is automatically opened if needed. An automatically opened socket is not returned to the closed state upon failure. The algorithm, known as a composed asynchronous operation, is implemented in terms of calls to the underlying socket's async_connect function. If the timeout timer expires while the operation is outstanding, the current connection attempt will be canceled and the completion handler will be invoked with the error error::timeout.





A sequence of endpoints. This this object must meet the requirements of EndpointSequence.


The completion handler to invoke when the operation completes. The implementation takes ownership of the handler by performing a decay-copy. The equivalent function signature of the handler must be:

void handler(
    // Result of operation. if the sequence is empty, set to
    // net::error::not_found. Otherwise, contains the
    // error from the last connection attempt.
    error_code const & error,

    // On success, the successfully connected endpoint.
    // Otherwise, a default-constructed endpoint.
    typename Protocol::endpoint const & endpoint

Regardless of whether the asynchronous operation completes immediately or not, the handler will not be invoked from within this function. Invocation of the handler will be performed in a manner equivalent to using net::post.

Per-Operation Cancellation

This asynchronous operation supports cancellation for the following net::cancellation_type values:

if they are also supported by the socket's async_connect operation.