This adds the type inference to Union types and add a small test case
for it, ensuring it keeps working in future.
Fixes: #5277
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
We need to add the `T: Index<Arg>` obligation to be resolved later as well,
otherwise we can't make inferences about `Arg` later based on the `Index` impls.
This still doesn't fix indexing with integer variables though; there's a further
problem with Chalk floundering because of the variable, I think.
This means we need to keep track of the kinds (general/int/float) of variables
in `Canonical`, which requires some more ceremony. (It also exposes some places
where we're not really dealing with canonicalization correctly -- another thing
to be cleaned up when we switch to using Chalk's types directly.)
Should fix the last remaining issue of #2534.
If the first type parameter gets inferred, that's still not handled correctly;
it'll require some more refactoring: E.g. if we have `Thing<T, F=fn() -> T>` and
then instantiate `Thing<_>`, that gets turned into `Thing<_, fn() -> _>` before
the `_` is instantiated into a type variable -- so afterwards, we have two type
variables without any connection to each other.
5033: Order of glob imports should not affect import shadowing r=Nashenas88 a=Nashenas88
Fixes#5032
Co-authored-by: Paul Daniel Faria <Nashenas88@users.noreply.github.com>
4958: Infer FnSig via Fn traits r=flodiebold a=adamrk
Addresses https://github.com/rust-analyzer/rust-analyzer/issues/4481.
When inferring types check if the callee implements one of the builtin `Fn` traits. Also autoderef the callee before trying to figure out it's `FnSig`.
Co-authored-by: adamrk <ark.email@gmail.com>
When referring to an associated type of a super trait, we used the substs of the
subtrait. That led to the #4931 crash if the subtrait had less parameters, but
it could also lead to other incorrectness if just the order was different.
Fixes#4931.
This is working, but I'm not that happy with how the lowering works. We might
need an additional representation between `TypeRef` and `Ty` where names are
resolved and `impl Trait` bounds are separated out, but things like inference
variables don't exist and `impl Trait` is always represented the same
way.
Also note that this doesn't implement correct handling of RPIT *inside* the
function (which involves turning the `impl Trait`s into variables and creating
obligations for them). That intermediate representation might help there as
well.
4651: Use first match branch in case of type mismatch, not last r=kjeremy a=flodiebold
The comment says this was intentional, but I do agree with #4304 that it makes
more sense the other way around (for if/else as well).
Fixes#4304.
Co-authored-by: Florian Diebold <florian.diebold@freiheit.com>
Function pointers can be 'higher-ranked' over lifetimes, which is why they're
not an application type in Chalk, but since we don't model lifetimes it doesn't
matter for us yet.
4497: Create LowerCtx on the fly r=matklad a=edwin0cheng
Previously we create `LowerCtx` at the beginning of lowering, however, the hygiene content is in fact changing between macro expression expanding.
This PR change it to create the `LowerCtx` on the fly to fix above bug.
However, #4465 is not fixed by this PR, the goto-def is still not work yet. It only fixed the infer part.
Co-authored-by: Edwin Cheng <edwin0cheng@gmail.com>
This fixes an issue where the following code sample would fail to infer
the type contained in the option:
```rust
fn main() {
let mut end = None; // TODO: Fix inference for this in RA
loop {
end = Some(true);
}
}
```
