// Check that when we test the supertrait we ensure consistent use of // lifetime parameters. In this case, implementing T2<'a,'b> requires // an impl of T1<'a>, but we have an impl of T1<'b>. trait T1<'x> { fn x(&self) -> &'x isize; } trait T2<'x, 'y> : T1<'x> { fn y(&self) -> &'y isize; } struct S<'a, 'b> { a: &'a isize, b: &'b isize } impl<'a,'b> T1<'b> for S<'a, 'b> { fn x(&self) -> &'b isize { self.b } } impl<'a,'b> T2<'a, 'b> for S<'a, 'b> { //~ ERROR cannot infer an appropriate lifetime fn y(&self) -> &'b isize { self.b } } pub fn main() { }