mirror of https://github.com/rust-lang/rust
46 lines
940 B
Rust
46 lines
940 B
Rust
//@ check-pass
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//
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// Check that computing the lub works even for empty binders.
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fn lt<'a: 'a>() -> &'a () {
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&()
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}
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fn lt_in_fn<'a: 'a>() -> fn(&'a ()) {
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|_| ()
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}
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struct Contra<'a>(fn(&'a ()));
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fn lt_in_contra<'a: 'a>() -> Contra<'a> {
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Contra(|_| ())
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}
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fn ok<'a, 'b, 'upper, 'lower>(v: bool)
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where
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'upper: 'a,
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'upper: 'b,
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'a: 'lower,
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'b: 'lower,
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{
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let _: &'lower () = match v {
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true => lt::<'a>(),
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false => lt::<'b>(),
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};
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// This errored in the past because LUB and GLB always
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// bailed out when encountering binders, even if they were
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// empty.
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let _: fn(&'upper ()) = match v {
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true => lt_in_fn::<'a>(),
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false => lt_in_fn::<'b>(),
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};
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// This was already accepted, as relate didn't encounter any binders.
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let _: Contra<'upper> = match v {
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true => lt_in_contra::<'a>(),
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false => lt_in_contra::<'b>(),
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};
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}
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fn main() {}
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