{{alias}}( xdtype, ydtype, policy )
    Resolves the output ndarray data type for a binary function.

    The function always applies type promotion to the provided data types,
    except for the following policies:

    - default
    - default_index
    - same
    - <dtype>

    Parameters
    ----------
    xdtype: string|DataType
        First input ndarray data type.

    ydtype: string|DataType
        Second input ndarray data type.

    policy: string|DataType
        Output ndarray data type policy. If `policy` is a data type, the
        function returns the `policy` value.

    Returns
    -------
    out: DataType
        Output ndarray data type.

    Examples
    --------
    > var dt = {{alias}}( 'float64', 'float32', 'real' );
    > String( dt )
    'float64'

    See Also
    --------