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// Test that we can deduce when projections like `T::Item` outlive the
// function body. Test that this does not imply that `T: 'a` holds.
// compile-flags:-Zverbose
use std::cell::Cell;
fn twice<F, T>(mut value: T, mut f: F)
where
F: FnMut(&T, Cell<&Option<T::Item>>),
T: Iterator,
{
let mut n = value.next();
f(&value, Cell::new(&n));
f(&value, Cell::new(&n));
}
fn generic1<T: Iterator>(value: T) {
// No error here:
twice(value, |value_ref, item| invoke1(item));
}
fn invoke1<'a, T>(x: Cell<&'a Option<T>>)
where
T: 'a,
{
}
fn generic2<T: Iterator>(value: T) {
twice(value, |value_ref, item| invoke2(value_ref, item));
//~^ ERROR the parameter type `T` may not live long enough
}
fn invoke2<'a, T, U>(a: &T, b: Cell<&'a Option<U>>)
where
T: 'a,
{
}
fn main() {}
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