1 // Various unsuccessful attempts to put the unboxed closure kind
2 // inference into an awkward position that might require fixed point
3 // iteration (basically where inferring the kind of a closure `c`
4 // would require knowing the kind of `c`). I currently believe this is
5 // impossible.
6 
a()7 fn a() {
8     let mut closure0 = None;
9     let vec = vec![1, 2, 3];
10 
11     loop {
12         {
13             let closure1 = || {
14                 match closure0.take() {
15                     Some(c) => {
16                         return c();
17                         //~^ ERROR type annotations needed
18                     }
19                     None => { }
20                 }
21             };
22             closure1();
23         }
24 
25         closure0 = || vec;
26     }
27 }
28 
main()29 fn main() { }
30