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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
|
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`
|
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
|
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
|
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
|
6 | fn foo<'a>(&'a self, x: &'a Foo) -> &'a Foo {
| ++
```
62 lines
1.4 KiB
Rust
62 lines
1.4 KiB
Rust
//@ run-rustfix
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#![feature(arbitrary_self_types)]
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#![allow(non_snake_case, dead_code)]
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use std::marker::PhantomData;
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use std::ops::Deref;
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use std::pin::Pin;
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struct Struct {}
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struct Wrap<T, P>(T, PhantomData<P>);
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impl<T, P> Deref for Wrap<T, P> {
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type Target = T;
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fn deref(&self) -> &T {
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&self.0
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}
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}
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impl Struct {
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// Test using `&self` sugar:
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fn ref_self<'a>(&self, f: &'a u32) -> &'a u32 {
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f
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//~^ ERROR lifetime may not live long enough
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}
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// Test using `&Self` explicitly:
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fn ref_Self<'a>(self: &Self, f: &'a u32) -> &'a u32 {
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f
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//~^ ERROR lifetime may not live long enough
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}
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fn box_ref_Self<'a>(self: Box<&Self>, f: &'a u32) -> &'a u32 {
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f
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//~^ ERROR lifetime may not live long enough
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}
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fn pin_ref_Self<'a>(self: Pin<&Self>, f: &'a u32) -> &'a u32 {
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f
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//~^ ERROR lifetime may not live long enough
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}
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fn box_box_ref_Self<'a>(self: Box<Box<&Self>>, f: &'a u32) -> &'a u32 {
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f
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//~^ ERROR lifetime may not live long enough
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}
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fn box_pin_ref_Self<'a>(self: Box<Pin<&Self>>, f: &'a u32) -> &'a u32 {
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f
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//~^ ERROR lifetime may not live long enough
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}
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fn wrap_ref_Self_Self<'a>(self: Wrap<&Self, Self>, f: &'a u8) -> &'a u8 {
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f
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//~^ ERROR lifetime may not live long enough
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}
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}
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fn main() {}
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