Improve coverage results on certain derived traits that show two different counters · Issue #79626 · rust-lang/rust (original) (raw)

The derived traits get coverage, which is great, but some of the traits appear to get two coverage execution counts at different positions:

   4|      2|#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
                      ^0            ^0      ^0 ^0  ^1       ^0 ^0^0
```text

`PartialEq`, `PartialOrd`, and `Ord` (and possibly `Eq`, if the trait name was longer than 2
characters) have counts at their first and last characters.

Why is this? Why does `PartialOrd` have two values (1 and 0)? This must mean we are checking distinct coverages, so maybe we don't want to eliminate one of them. Should we merge them? If merged, do we lose some information?