Matthias Krüger da43826398 Rollup merge of #139774 - compiler-errors:supertrait-alias, r=lcnr ... Fix replacing supertrait aliases in `ReplaceProjectionWith` The new solver has a procedure called `predicates_for_object_candidate`, which elaborates the super-bounds and item-bounds that are required to hold for a dyn trait to implement something via a built-in object impl. In that procedure, there is a folder called `ReplaceProjectionWith` which is responsible for replacing projections that reference `Self`, so that we don't encounter cycles when we then go on to normalize those projections in the process of proving these super-bounds. That folder had a few problems: Firstly, it wasn't actually checking that this was a super bound originating from `Self`. Secondly, it only accounted for a *single* projection type def id, but trait objects can have multiple (i.e. `trait Foo<A, B>: Bar<A, Assoc = A> + Bar<B, Assoc = B>`). To fix the first, it's simple enough to just add an equality check for the self ty. To fix the second, I implemented a matching step that's very similar to the `projection_may_match` check we have for upcasting, since on top of having multiple choices, we need to deal with both non-structural matches and ambiguity. This probably lacks a bit of documentation, but I think it works pretty well. Fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/171 r? lcnr		2025-04-17 17:40:27 +02:00
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src	Rollup merge of #139774 - compiler-errors:supertrait-alias, r=lcnr	2025-04-17 17:40:27 +02:00
Cargo.toml	Revert "Use workspace lints for crates in compiler/ #138084"	2025-03-10 18:12:47 +08:00