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// Regression test for #74429, where we didn't think that a type parameter
// outlived `ReEmpty`.
// check-pass
use std::marker::PhantomData;
fn apply<T, F: FnOnce(T)>(_: T, _: F) {}
#[derive(Clone, Copy)]
struct Invariant<T> {
t: T,
p: PhantomData<fn(T) -> T>,
}
fn verify_reempty<T>(x: T) {
// r is inferred to have type `Invariant<&ReEmpty(U0) T>`
let r = Invariant { t: &x, p: PhantomData };
// Creates a new universe, all variables from now on are in `U1`, say.
let _: fn(&()) = |_| {};
// Closure parameter is of type `&ReEmpty(U1) T`, so the closure has an implied
// bound of `T: ReEmpty(U1)`
apply(&x, |_| {
// Requires `typeof(r)` is well-formed, i.e. `T: ReEmpty(U0)`. If we
// only have the implied bound from the closure parameter to use this
// requires `ReEmpty(U1): ReEmpty(U0)`, which isn't true so we reported
// an error.
//
// This doesn't happen any more because we ensure that `T: ReEmpty(U0)`
// is an implicit bound for all type parameters.
drop(r);
});
}
fn main() {}
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