| //@ run-pass | |
| struct A<F: FnOnce()->T,T>(F::Output); | |
| struct B<F: FnOnce()->T,T>(A<F,T>); | |
| // Removing Option causes it to compile. | |
| fn foo<T,F: FnOnce()->T>(f: F) -> Option<B<F,T>> { | |
| Some(B(A(f()))) | |
| } | |
| fn main() { | |
| let v = (|| foo(||4))(); | |
| match v { | |
| Some(B(A(4))) => {}, | |
| _ => unreachable!() | |
| } | |
| } |