A single match statement inside a function inside an impl is already 4 levels of indentation.

How about this?

The preferred way to ease multiple indentation levels in a switch statement is to align the switch and its subordinate case labels in the same column instead of double-indenting the case labels. E.g.:

switch (suffix) {
case 'G':
case 'g':
        mem <<= 30;
        break;
case 'M':
case 'm':
        mem <<= 20;
        break;
case 'K':
case 'k':
        mem <<= 10;
        /* fall through */
default:
        break;
}

I had some luck applying this to match statements. My example:

let x = 5;

match x {
5 => foo(),
3 => bar(),
1 => match baz(x) {
	Ok(_) => foo2(),
	Err(e) => match maybe(e) {
		Ok(_) => bar2(),
		_ => panic!(),
		}
	}
_ => panic!(),
}

Is this acceptable, at least compared to the original switch statement idea?