mirror of https://github.com/rust-lang/rust
70 lines
2.4 KiB
Rust
70 lines
2.4 KiB
Rust
// Test the interaction between rested RPIT and HRTB.
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trait Foo<'a> {
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type Assoc;
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}
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impl Foo<'_> for () {
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type Assoc = ();
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}
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// Alternative version of `Foo` whose impl uses `'a`.
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trait Bar<'a> {
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type Assoc;
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}
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impl<'a> Bar<'a> for () {
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type Assoc = &'a ();
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}
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trait Qux<'a> {}
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impl Qux<'_> for () {}
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// This is not supported.
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fn one_hrtb_outlives() -> impl for<'a> Foo<'a, Assoc = impl Sized + 'a> {}
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//~^ ERROR `impl Trait` cannot capture higher-ranked lifetime from outer `impl Trait`
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// This is not supported.
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fn one_hrtb_trait_param() -> impl for<'a> Foo<'a, Assoc = impl Qux<'a>> {}
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//~^ ERROR `impl Trait` cannot capture higher-ranked lifetime from outer `impl Trait`
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fn one_hrtb_outlives_uses() -> impl for<'a> Bar<'a, Assoc = impl Sized + 'a> {}
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//~^ ERROR `impl Trait` cannot capture higher-ranked lifetime from outer `impl Trait`
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//~| ERROR implementation of `Bar` is not general enough
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fn one_hrtb_trait_param_uses() -> impl for<'a> Bar<'a, Assoc = impl Qux<'a>> {}
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//~^ ERROR `impl Trait` cannot capture higher-ranked lifetime from outer `impl Trait`
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// This should resolve.
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fn one_hrtb_mention_fn_trait_param<'b>() -> impl for<'a> Foo<'a, Assoc = impl Qux<'b>> {}
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// This should resolve.
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fn one_hrtb_mention_fn_outlives<'b>() -> impl for<'a> Foo<'a, Assoc = impl Sized + 'b> {}
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// This should resolve.
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fn one_hrtb_mention_fn_trait_param_uses<'b>() -> impl for<'a> Bar<'a, Assoc = impl Qux<'b>> {}
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//~^ ERROR the trait bound `for<'a> &'a (): Qux<'b>` is not satisfied
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// This should resolve.
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fn one_hrtb_mention_fn_outlives_uses<'b>() -> impl for<'a> Bar<'a, Assoc = impl Sized + 'b> {}
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//~^ ERROR implementation of `Bar` is not general enough
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// This should resolve.
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fn two_htrb_trait_param() -> impl for<'a> Foo<'a, Assoc = impl for<'b> Qux<'b>> {}
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// `'b` is not in scope for the outlives bound.
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fn two_htrb_outlives() -> impl for<'a> Foo<'a, Assoc = impl for<'b> Sized + 'b> {}
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//~^ ERROR use of undeclared lifetime name `'b` [E0261]
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// This should resolve.
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fn two_htrb_trait_param_uses() -> impl for<'a> Bar<'a, Assoc = impl for<'b> Qux<'b>> {}
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//~^ ERROR: the trait bound `for<'a, 'b> &'a (): Qux<'b>` is not satisfied
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// `'b` is not in scope for the outlives bound.
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fn two_htrb_outlives_uses() -> impl for<'a> Bar<'a, Assoc = impl for<'b> Sized + 'b> {}
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//~^ ERROR use of undeclared lifetime name `'b` [E0261]
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//~| ERROR implementation of `Bar` is not general enough
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fn main() {}
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