3 // Test that vec is now covariant in its argument type.
7 fn foo<'a,'b>(v1: Vec<&'a i32>, v2: Vec<&'b i32>) -> i32 {
8 bar(v1, v2).cloned().unwrap_or(0) // only type checks if we can intersect 'a and 'b
11 fn bar<'c>(v1: Vec<&'c i32>, v2: Vec<&'c i32>) -> Option<&'c i32> {
12 v1.get(0).cloned().or_else(|| v2.get(0).cloned())
18 assert_eq!(foo(vec![&x], vec![&y]), 22);
19 assert_eq!(foo(vec![&y], vec![&x]), 44);