def as_tuple_chk(x_dec):
    """Convert `Decimal` to `DecimalTuple` and check finite.

    Parameters
    ----------
    x_dec : Decimal
        Input value in decimal.

    Returns
    -------
    x_tup : DecimalTuple
        Input converted to `DecimalTuple`.
    """
    if not x_dec.is_finite():
        raise ValueError("only accepts finite input")
    x_tup = x_dec.as_tuple()
    return x_tup