To do this we need to carry around the original resolution a bit, because `Self`
gets resolved to the actual type immediately, but you're not allowed to write
the equivalent type in a projection. (I tried just comparing the projection base
type with the impl self type, but that seemed too dirty.) This is basically how
rustc does it as well.
Fixes#3249.
3494: Implement include macro r=matklad a=edwin0cheng
This PR implement builtin `include` macro.
* It does not support include as expression yet.
* It doesn't consider `env!("OUT_DIR")` yet.
Co-authored-by: Edwin Cheng <edwin0cheng@gmail.com>
3385: Fix#3373 r=matklad a=flodiebold
Basically, we need to allow variables in the caller self type to unify with the
impl's declared self type. That requires some more contortions in the variable
handling. I'm looking forward to (hopefully) handling this in a cleaner way when
we switch to Chalk's types and unification code.
Co-authored-by: Florian Diebold <flodiebold@gmail.com>
Basically, we need to allow variables in the caller self type to unify with the
impl's declared self type. That requires some more contortions in the variable
handling. I'm looking forward to (hopefully) handling this in a cleaner way when
we switch to Chalk's types and unification code.
E.g. for `&{ some_string() }` in a context where a `&str` is expected, we
reported a mismatch inside the block. The problem is that we're passing an
expectation of `str` down, but the expectation is more of a hint in this case.
There's a long comment in rustc about this, which I just copied.
Also, fix reported location for type mismatches in macros.
E.g. in `match x { None => ... }`, `None` is a path pattern (resolving to the
option variant), not a binding. To determine this, we need to try to resolve the
name during lowering. This isn't too hard since we already need to resolve names
for macro expansion anyway (though maybe a bit hacky).
Fixes#1618.
3147: Check that impl self type matches up with expected self type in path mode r=matklad a=flodiebold
Fixes#3144.
Co-authored-by: Florian Diebold <flodiebold@gmail.com>
Basically, `Iterator` is re-exported via several steps, which happened to not be
resolved yet when we got to the prelude import, but since the name resolved to
the reexport from `core::iter` (just to no actual items), we gave up trying to
resolve it further.
Maybe part of the problem is that we can have
`PartialResolvedImport::Unresolved` or `PartialResolvedImport::Indeterminate`
with `None` in all namespaces, and handle them differently.
Fixes#2683.
The `-` turned into a `+` during a refactoring.
The original issue was caused by `Read` resolving wrongly to a trait without
type parameters instead of a struct with one parameter; this only fixes the
crash, not the wrong resolution.
2661: Implement infer await from async function r=flodiebold a=edwin0cheng
This PR is my attempt for trying to add support for infer `.await` expression from an `async` function, by desugaring its return type to `Impl Future<Output=RetType>`.
Note that I don't know it is supposed to desugaring it in that phase, if it is not suitable in current design, just feel free to reject it :)
r=@flodiebold
Co-authored-by: Edwin Cheng <edwin0cheng@gmail.com>
It's not very different, except we can directly use Salsa IDs instead of casting
them. This means we need to refactor the handling of errors to get rid of
UNKNOWN_TRAIT though.
2623: Add support macros in impl blocks r=matklad a=edwin0cheng
This PR add support for macros in impl blocks, which reuse `Expander` for macro expansion.
see also: #2459
Co-authored-by: Edwin Cheng <edwin0cheng@gmail.com>
When calling a function, argument-position impl Trait is transparent; same for
return-position impl Trait when inside the function. So in these cases, we need
to represent that type not by `Ty::Opaque`, but by a type variable that can be
unified with whatever flows into there.
If we are expecting a `&Foo` and get a `&something`, when checking the
`something`, we are *expecting* a `Foo`, but we shouldn't try to unify whatever
we get with that expectation, because it could actually be a `&Foo`, and `&&Foo`
coerces to `&Foo`. So this fixes quite a few false type mismatches.
