tests/ui/closures/2229_closure_analysis/migrations/insignificant_drop_attr_no_migrations.rs

   1 // run-pass
   2
   3 #![deny(rust_2021_incompatible_closure_captures)]
   4 #![feature(rustc_attrs)]
   5 #![allow(unused)]
   6 #[rustc_insignificant_dtor]
   7
   8 struct InsignificantDropPoint {
   9     x: i32,
  10     y: i32,
  11 }
  12
  13 impl Drop for InsignificantDropPoint {
  14     fn drop(&mut self) {}
  15 }
  16
  17 struct GenericStruct<T>(T, T);
  18
  19 // No drop reordering is required as the elements of `t` implement insignificant drop
  20 fn insignificant_drop_does_not_need_migration() {
  21     let t = (InsignificantDropPoint { x: 4, y: 9 }, InsignificantDropPoint { x: 4, y: 9 });
  22
  23     let c = || {
  24         let _t = t.0;
  25     };
  26
  27     c();
  28 }
  29
  30 // Generic struct whose elements don't have significant drops don't need drop reordering
  31 fn generic_struct_with_insignificant_drop_does_not_need_migration() {
  32     let t =
  33         GenericStruct(InsignificantDropPoint { x: 4, y: 9 }, InsignificantDropPoint { x: 4, y: 9 });
  34
  35     let c = || {
  36         let _t = t.0;
  37     };
  38
  39     c();
  40 }
  41
  42 fn main() {
  43     insignificant_drop_does_not_need_migration();
  44     generic_struct_with_insignificant_drop_does_not_need_migration();
  45 }