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