1 #![feature(generic_associated_types)] 2 3 trait X { 4 type Y<'x>; 5 } 6 main()7 fn main() { 8 fn _f(arg : Box<dyn for<'a> X<Y<'x> = &'a [u32]>>) {} 9 //~^ ERROR: use of undeclared lifetime name `'x` 10 //~| ERROR: binding for associated type `Y` references lifetime 11 } 12