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###### basic_stream::async_connect (2 of 5 overloads)

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

###### Synopsis

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

###### Description

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`.

###### Parameters

Name | Description
--- | ---
`endpoints` | A sequence of endpoints. This this object must meet the requirements of EndpointSequence.

`handler`

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:

- `net::cancellation_type::terminal`
- `net::cancellation_type::partial`
- `net::cancellation_type::total`

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