tests/ui/rfcs/rfc-2528-type-changing-struct-update/feature-gate.rs

   1 // gate-test-type_changing_struct_update
   2
   3 #[derive(Debug)]
   4 struct Machine<S> {
   5     state: S,
   6     common_field1: &'static str,
   7     common_field2: i32,
   8 }
   9 #[derive(Debug)]
  10 struct State1;
  11 #[derive(Debug, PartialEq)]
  12 struct State2;
  13
  14 fn update_to_state2() {
  15     let m1: Machine<State1> = Machine {
  16         state: State1,
  17         common_field1: "hello",
  18         common_field2: 2,
  19     };
  20     let m2: Machine<State2> = Machine {
  21         state: State2,
  22         ..m1
  23         //~^ ERROR type changing struct updating is experimental [E0658]
  24         //~| ERROR mismatched types [E0308]
  25     };
  26     assert_eq!(State2, m2.state);
  27 }
  28
  29 fn main() {}