*sock* must be a non-blocking socket.
+ With :class:`SelectorEventLoop`, *address* does not need to be resolved:
+ for :const:`~socket.AF_INET` and :const:`~socket.AF_INET6` sockets,
+ ``sock_connect`` first checks whether *address* is already resolved by
+ calling :func:`socket.inet_pton`, and uses :meth:`loop.getaddrinfo` to
+ resolve it if it is not.
+
+ :class:`ProactorEventLoop`, the default event loop on Windows, does not
+ resolve *address*. The host must already be a numeric IP address; passing
+ a host name raises :exc:`OSError`. Resolve the address with
+ :meth:`loop.getaddrinfo` first, or use :meth:`loop.create_connection`,
+ which resolves the address on every platform.
+
.. versionchanged:: 3.5.2
- ``address`` no longer needs to be resolved. ``sock_connect``
- will try to check if the *address* is already resolved by calling
- :func:`socket.inet_pton`. If not,
- :meth:`loop.getaddrinfo` will be used to resolve the
- *address*.
+ With :class:`SelectorEventLoop`, ``address`` no longer needs to be
+ resolved.
.. seealso::