src/test/ui/impl-trait/auto-trait-leak-rpass.rs

   1 // run-pass
   2
   3 // Fast path, main can see the concrete type returned.
   4 fn before() -> impl FnMut(i32) {
   5     let mut p = Box::new(0);
   6     move |x| *p = x
   7 }
   8
   9 fn send<T: Send>(_: T) {}
  10
  11 fn main() {
  12     send(before());
  13     send(after());
  14 }
  15
  16 // Deferred path, main has to wait until typeck finishes,
  17 // to check if the return type of after is Send.
  18 fn after() -> impl FnMut(i32) {
  19     let mut p = Box::new(0);
  20     move |x| *p = x
  21 }