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.
Steve Klabnik
bors
Josh Stone
Niko Matsakis
Kevin Butler
Richard Diamond
Jethro Beekman
Eli Friedman
Brian Anderson
Daniel Rollins
JP Sugarbroad
Andrew Paseltiner
angelsl
Vadim Petrochenkov
Marcell Pardavi
Simonas Kazlauskas