1 #![feature(unboxed_closures)]
2 
to_fn_mut<A,F:FnMut<A>>(f: F) -> F3 fn to_fn_mut<A,F:FnMut<A>>(f: F) -> F { f }
4 
main()5 fn main() {
6     let mut_ = to_fn_mut(|x| x);
7     mut_.call((0, )); //~ ERROR no method named `call` found
8 }
9