overhaul &mut suggestions in borrowck errors
#145013
Conversation
|
r? @nnethercote rustbot has assigned @nnethercote. Use |
rustbot
added
S-waiting-on-review
There was a problem hiding this comment.
I have only looked at the tests and their outputs so far, some of the suggestions seem suboptimal. Is this expected?
@rustbot author
| | | ||
| LL | let x: &[isize] = &mut [1, 2, 3, 4, 5]; | ||
| | +++ | ||
| LL | let x: &mut [isize] = &[1, 2, 3, 4, 5]; |
There was a problem hiding this comment.
This is still invalid, it needs to be &mut [1, 2, 3, 4, 5].
| | | ||
| LL | let x = &mut 0 as *const i32; | ||
| | +++ | ||
| LL | let x: *mut i32 = &0 as *const i32; |
There was a problem hiding this comment.
Also still invalid, let x = &mut 0 as *mut i32; would work, without needing the type annotation.
| help: consider changing this binding's type | ||
| | | ||
| LL - let ptr_x: *const _ = &x; | ||
| LL + let ptr_x: *mut i32 = &x; |
There was a problem hiding this comment.
Should be &x instead of &mut x.
| help: consider using `get_mut` | ||
| | | ||
| LL - let string = &map[&0]; | ||
| LL + let string = map.get_mut(&0).unwrap(); |
There was a problem hiding this comment.
It's a bit confusing that the suggestion is on a different line to the one mentioned earlier in the error. Is it possible to indicate that the line needing to be changed is on line 6?
There was a problem hiding this comment.
Is it possible to indicate that the line needing to be changed is on line 6?
Yes, that is the LL annotation on the left, which gets normalized here but would have printed normally if it isn't in an UI test
There was a problem hiding this comment.
or would you like me to explicitly say "consider using get_mut on line 6"? that's possible too
There was a problem hiding this comment.
Oh right, that's fine then.
| help: consider using `get_mut` | ||
| | | ||
| LL - let string = &map[&0]; | ||
| LL + let string = map.get_mut(&0).unwrap(); |
| | | ||
| help: consider changing this to be a mutable reference | ||
| | | ||
| LL | let string = &mut vec[0]; |
Indeximpl for which theIndexMuttrait does not apply, do not suggest addingmutafter&.get_mutwithunwrapif error is fired onBTreeMaporHashMap.Supersedes #144018 cc @xizheyin
Closes #143732