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1775e7b93d
Do not suggest constraining the `&self` param, but rather the return type.
If that is wrong (because it is not sufficient), a follow up error will tell the
user to fix it. This way we lower the chances of *over* constraining, but still
get the cake of "correctly" contrained in two steps.
This is a correct suggestion:
```
error: lifetime may not live long enough
--> $DIR/ex3-both-anon-regions-return-type-is-anon.rs:9:9
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LL | fn foo<'a>(&self, x: &i32) -> &i32 {
| - - let's call the lifetime of this reference `'1`
| |
| let's call the lifetime of this reference `'2`
LL | x
| ^ method was supposed to return data with lifetime `'2` but it is returning data with lifetime `'1`
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help: consider introducing a named lifetime parameter and update trait if needed
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LL | fn foo<'a>(&self, x: &'a i32) -> &'a i32 {
| ++ ++
```
While this is incomplete because it should suggestino `&'a self`
```
error: lifetime may not live long enough
--> $DIR/ex3-both-anon-regions-self-is-anon.rs:7:19
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LL | fn foo<'a>(&self, x: &Foo) -> &Foo {
| - - let's call the lifetime of this reference `'1`
| |
| let's call the lifetime of this reference `'2`
LL | if true { x } else { self }
| ^ method was supposed to return data with lifetime `'2` but it is returning data with lifetime `'1`
|
help: consider introducing a named lifetime parameter and update trait if needed
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LL | fn foo<'a>(&self, x: &'a Foo) -> &'a Foo {
| ++ ++
```
but the follow up error is
```
error: lifetime may not live long enough
--> tests/ui/lifetimes/lifetime-errors/ex3-both-anon-regions-self-is-anon.rs:7:30
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6 | fn foo<'a>(&self, x: &'a Foo) -> &'a Foo {
| -- - let's call the lifetime of this reference `'1`
| |
| lifetime `'a` defined here
7 | if true { x } else { self }
| ^^^^ method was supposed to return data with lifetime `'a` but it is returning data with lifetime `'1`
|
help: consider introducing a named lifetime parameter and update trait if needed
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6 | fn foo<'a>(&'a self, x: &'a Foo) -> &'a Foo {
| ++
```
38 lines
1.6 KiB
Plaintext
38 lines
1.6 KiB
Plaintext
error[E0308]: `match` arms have incompatible types
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--> $DIR/issue-17728.rs:108:14
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LL | / match to_parse {
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LL | | "w" | "west" => RoomDirection::West,
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LL | | "e" | "east" => RoomDirection::East,
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LL | | "n" | "north" => RoomDirection::North,
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... |
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LL | | "down" => RoomDirection::Down,
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| | ------------------- this and all prior arms are found to be of type `RoomDirection`
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LL | | _ => None
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| | ^^^^ expected `RoomDirection`, found `Option<_>`
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LL | | }
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| |_____- `match` arms have incompatible types
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= note: expected enum `RoomDirection`
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found enum `Option<_>`
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error: lifetime may not live long enough
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--> $DIR/issue-17728.rs:15:28
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LL | fn attemptTraverse(&self, room: &Room, directionStr: &str) -> Result<&Room, &str> {
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| - - let's call the lifetime of this reference `'1`
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| |
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| let's call the lifetime of this reference `'2`
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...
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LL | Some(entry) => Ok(entry),
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| ^^^^^^^^^ method was supposed to return data with lifetime `'2` but it is returning data with lifetime `'1`
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help: consider introducing a named lifetime parameter
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LL | fn attemptTraverse<'a>(&self, room: &'a Room, directionStr: &str) -> Result<&'a Room, &'a str> {
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| ++++ ++ ++ ++
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error: aborting due to 2 previous errors
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For more information about this error, try `rustc --explain E0308`.
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