How to find comparisons of a given type?

help
1

I have a giant Rust codebase (one workspace containing a bunch of crates) that contains something like this:

pub struct Foo { .. }

impl PartialOrd for Foo {
    fn partial_cmp((&self, other: &Self) -> Option<Ordering> { .. }
}
// also `Eq` and `PartialEq` are implemented consistently with `PartialOrd`

Is there a way I can find all the places in my codebase where I'm comparing two instances of Foo using my PartialOrd implementation?

I've tried using rust-analyzer's "go to reference" functionality, but it only finds explicit calls to the partial_cmp function, and not any of the comparison operators (like <). I've also tried adding explicit definitions of the comparison functions (e.g. overriding fn lt(..)) to "go to reference" on it, but it also misses the comparison operators, as it'll find x.lt(&y), but not x < y).

2

You can comment out these impls so that you get errors wherever you're using the comparison operators. This seems like something rust-analyzer should be able to do, though, so maybe open a feature request?

1 Like
3

Sadly, if one crate in the workspace fails to compile because of the missing comparison, then it can't try to build any crates that depend on that failing crate, so that's potentially a very long, manual process.

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