mirror of https://github.com/rust-lang/rust
36 lines
968 B
Rust
36 lines
968 B
Rust
#![feature(coroutine_trait)]
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#![feature(coroutines)]
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use std::ops::Coroutine;
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struct Contravariant<'a>(fn(&'a ()));
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struct Covariant<'a>(fn() -> &'a ());
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fn bad1<'short, 'long: 'short>() -> impl Coroutine<Covariant<'short>> {
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#[coroutine] |_: Covariant<'short>| {
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let a: Covariant<'long> = yield ();
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//~^ ERROR lifetime may not live long enough
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}
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}
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fn bad2<'short, 'long: 'short>() -> impl Coroutine<Contravariant<'long>> {
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#[coroutine] |_: Contravariant<'long>| {
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let a: Contravariant<'short> = yield ();
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//~^ ERROR lifetime may not live long enough
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}
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}
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fn good1<'short, 'long: 'short>() -> impl Coroutine<Covariant<'long>> {
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#[coroutine] |_: Covariant<'long>| {
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let a: Covariant<'short> = yield ();
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}
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}
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fn good2<'short, 'long: 'short>() -> impl Coroutine<Contravariant<'short>> {
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#[coroutine] |_: Contravariant<'short>| {
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let a: Contravariant<'long> = yield ();
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}
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}
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fn main() {}
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