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4aba2c55e6
Start pointing to where bindings were declared when they are captured in closures:
```
error[E0597]: `x` does not live long enough
--> $DIR/suggest-return-closure.rs:23:9
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LL | let x = String::new();
| - binding `x` declared here
...
LL | |c| {
| --- value captured here
LL | x.push(c);
| ^ borrowed value does not live long enough
...
LL | }
| -- borrow later used here
| |
| `x` dropped here while still borrowed
```
Suggest cloning in more cases involving closures:
```
error[E0507]: cannot move out of `foo` in pattern guard
--> $DIR/issue-27282-move-ref-mut-into-guard.rs:11:19
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LL | if { (|| { let mut bar = foo; bar.take() })(); false } => {},
| ^^ --- move occurs because `foo` has type `&mut Option<&i32>`, which does not implement the `Copy` trait
| |
| `foo` is moved here
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= note: variables bound in patterns cannot be moved from until after the end of the pattern guard
help: consider cloning the value if the performance cost is acceptable
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LL | if { (|| { let mut bar = foo.clone(); bar.take() })(); false } => {},
| ++++++++
```
43 lines
1.6 KiB
Plaintext
43 lines
1.6 KiB
Plaintext
error[E0597]: `a` does not live long enough
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--> $DIR/location-insensitive-scopes-issue-117146.rs:10:18
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LL | let a = ();
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| - binding `a` declared here
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LL | let b = |_| &a;
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| --- -^
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| | ||
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| | |borrowed value does not live long enough
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| | returning this value requires that `a` is borrowed for `'static`
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| value captured here
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...
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LL | }
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| - `a` dropped here while still borrowed
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note: due to current limitations in the borrow checker, this implies a `'static` lifetime
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--> $DIR/location-insensitive-scopes-issue-117146.rs:20:22
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LL | fn bad<F: Fn(&()) -> &()>(_: F) {}
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| ^^^
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error: implementation of `Fn` is not general enough
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--> $DIR/location-insensitive-scopes-issue-117146.rs:13:5
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LL | bad(&b);
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| ^^^^^^^ implementation of `Fn` is not general enough
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= note: closure with signature `fn(&'2 ()) -> &()` must implement `Fn<(&'1 (),)>`, for any lifetime `'1`...
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= note: ...but it actually implements `Fn<(&'2 (),)>`, for some specific lifetime `'2`
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error: implementation of `FnOnce` is not general enough
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--> $DIR/location-insensitive-scopes-issue-117146.rs:13:5
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LL | bad(&b);
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| ^^^^^^^ implementation of `FnOnce` is not general enough
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= note: closure with signature `fn(&'2 ()) -> &()` must implement `FnOnce<(&'1 (),)>`, for any lifetime `'1`...
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= note: ...but it actually implements `FnOnce<(&'2 (),)>`, for some specific lifetime `'2`
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error: aborting due to 3 previous errors
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For more information about this error, try `rustc --explain E0597`.
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