mirror of https://github.com/rust-lang/rust
35 lines
1.5 KiB
Plaintext
35 lines
1.5 KiB
Plaintext
error: lifetime may not live long enough
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--> $DIR/regions-trait-object-subtyping.rs:15:5
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LL | fn foo3<'a,'b>(x: &'a mut dyn Dummy) -> &'b mut dyn Dummy {
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| -- -- lifetime `'b` defined here
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| lifetime `'a` defined here
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LL | // Without knowing 'a:'b, we can't coerce
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LL | x
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| ^ function was supposed to return data with lifetime `'b` but it is returning data with lifetime `'a`
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= help: consider adding the following bound: `'a: 'b`
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= note: requirement occurs because of a mutable reference to `dyn Dummy`
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= note: mutable references are invariant over their type parameter
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= help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance
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error: lifetime may not live long enough
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--> $DIR/regions-trait-object-subtyping.rs:22:5
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LL | fn foo4<'a:'b,'b>(x: Wrapper<&'a mut dyn Dummy>) -> Wrapper<&'b mut dyn Dummy> {
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| -- -- lifetime `'b` defined here
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| lifetime `'a` defined here
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LL | // We can't coerce because it is packed in `Wrapper`
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LL | x
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| ^ function was supposed to return data with lifetime `'a` but it is returning data with lifetime `'b`
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= help: consider adding the following bound: `'b: 'a`
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= note: requirement occurs because of a mutable reference to `dyn Dummy`
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= note: mutable references are invariant over their type parameter
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= help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance
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error: aborting due to 2 previous errors
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