efb1e3d676
Split `TypeFolder` and `FallibleTypeFolder` atwain
Right now there is a coherence problem with `TypeFolder` and `FallibleTypeFolder`. Namely, it's impossible to implement a `FallibleTypeFolder` that is generic over interner, b/c it has a *downstream* conflict with the blanket impl:
```
impl<I, F> FallibleTypeFolder<I> for F where F: TypeFolder<I> {}
```
Because downstream crates may implement `TypeFolder<SomeLocalInterner>` for the fallible type folder.
This PR removes the relationship between `FallibleTypeFolder` and `TypeFolder`; it leads to *modest* code duplication, but otherwise does not affect perf and really doesn't matter in general.
|
||
|---|---|---|
| .. | ||
| src | ||
| Cargo.toml | ||
| messages.ftl | ||
| README.md | ||
For more information about how rustc works, see the rustc dev guide.