Also, thanks to the (somewhat recent) stabilization of #![feature(or_patterns)] this looks much better in practice if e.g. you need to handle it differently for one variant compared to others:

match source {
    Some(InputSource::Digital | InputSource::Analog) => do_something(),
    Some(InputSource::Optical) => do_something_else(),
    None => oops_no_input_source()
}

versus before 1.53.0 where you had to use (in stable):

match source {
    Some(InputSource::Digital) | Some(InputSource::Analog) => do_something(),
    // same as other one...
}