mirror of https://github.com/rust-lang/rust
37 lines
722 B
Rust
37 lines
722 B
Rust
//@ build-pass
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// Ensures that we don't regress on "implementation is not general enough" when
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// normalizating under binders.
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#![feature(no_core)]
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pub trait Yokeable<'a> {
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type Output: 'a;
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}
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pub struct Yoke<Y: for<'a> Yokeable<'a>> {
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_yokeable: Y,
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}
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impl<Y: for<'a> Yokeable<'a>> Yoke<Y> {
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pub fn project<'this, P>(
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&'this self,
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_f: for<'a> fn(<Y as Yokeable<'a>>::Output, &'a ()) -> <P as Yokeable<'a>>::Output,
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) -> Yoke<P>
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where
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P: for<'a> Yokeable<'a>,
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{
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unimplemented!()
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}
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}
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pub fn slice(y: Yoke<&'static ()>) -> Yoke<&'static ()> {
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y.project(move |yk, _| yk)
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}
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impl<'a, T> Yokeable<'a> for &'static T {
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type Output = &'a T;
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}
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fn main() {}
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