expansion already by growing the RHS to be bigger than LHS (all the way
to `'static` if necessary). This is needed because contraction doesn't
handle givens. Fixes#28934.
empty region, and they complicate region inference to no particular end.
They also lead in some cases to spurious errors like #29048 (though in
some cases these errors are helpful in tracking down missing
constraints).
Fix corner case in privacy that was causing ICEs when the `source_did` was not crate-local.
Full confession: I only kinda sorta understand this code, but afaict it's legit for `source_did` to be from another crate.
r? @alexcrichton
when evaluating a recursive type, the `type_of` of the interior could be
still in progress, so trying to get its size would cause an ICE.
Fixes#19001
r? @eddyb
This makes the error message in #28981 a bit shorter (152 to 115 lines).
Previous output (the local impl was always printed twice when it conflicted with an external impl):
```
test.rs:3:1: 3:23 error: conflicting implementations for trait `core::ops::Deref` [E0119]
test.rs:3 impl<T> Deref for T {}
^~~~~~~~~~~~~~~~~~~~~~
test.rs:3:1: 3:23 help: run `rustc --explain E0119` to see a detailed explanation
test.rs:3:1: 3:23 note: conflicting implementation in crate `std`
test.rs:3 impl<T> Deref for T {}
^~~~~~~~~~~~~~~~~~~~~~
```
Output after this patch:
```
test.rs:3:1: 3:23 error: conflicting implementations for trait `core::ops::Deref` [E0119]
test.rs:3 impl<T> Deref for T {}
^~~~~~~~~~~~~~~~~~~~~~
test.rs:3:1: 3:23 help: run `rustc --explain E0119` to see a detailed explanation
note: conflicting implementation in crate `std`
```
Closes#29314
The code from #29314:
```rust
fn main() {
if let Some(b) = None {
()
} else {
1
};
}
```
now prints this:
```
test.rs:2:5: 6:6 error: `if let` arms have incompatible types: expected `()`, found `_` (expected (), found integral variable) [E0308]
test.rs:2 if let Some(b) = None {
test.rs:3 ()
test.rs:4 } else {
test.rs:5 1
test.rs:6 };
test.rs:2:5: 6:6 help: run `rustc --explain E0308` to see a detailed explanation
test.rs:4:12: 6:6 note: `if let` arm with an incompatible type
test.rs:4 } else {
test.rs:5 1
test.rs:6 };
error: aborting due to previous error
```
This commit generalises parsing of associative operators from left-associative
only (with some ugly hacks to support right-associative assignment) to properly
left/right-associative operators.
Parsing is still is not general enough to handle non-associative,
non-highest-precedence prefix or non-highest-precedence
postfix operators (e.g. `..` range syntax) and should be made to be.
Lastly, this commit adds support for parsing right-associative `<-` (left arrow)
operator with precedence higher than assignment as the operator for placement-in
feature.
---
This PR still needs various non-parser changes (e.g. src/grammar and tests) and I’m still working on these; the meat of the PR can already be reviewed, though, I think.
Please review carefully. I made sure that quirks I have discovered so far are preserved (see e.g. https://github.com/rust-lang/rust/issues/29071) and am looking for more corner cases as I continue to work on tests et al, but there may be something I haven’t noticed or accounted for.
EDIT: I’m also not sure I managed to preserve all the semantics with the range operator inside non-trivial expressions since these are a mess at the moment. Crater runs would be nice.
