1 #![allow(warnings)] 2 #![feature(in_band_lifetimes)] 3 foo(x: &'a u32, y: &u32) -> &'a u324fn foo(x: &'a u32, y: &u32) -> &'a u32 { y } //~ ERROR explicit lifetime required 5 foo2(x: &'a u32, y: &'b u32) -> &'a u326fn foo2(x: &'a u32, y: &'b u32) -> &'a u32 { y } //~ ERROR lifetime mismatch 7 main()8fn main() {} 9