src/test/ui/closures/2229_closure_analysis/migrations/precise.fixed

   1 // run-rustfix
   2
   3 #![deny(rust_2021_incompatible_closure_captures)]
   4 //~^ NOTE: the lint level is defined here
   5
   6 #[derive(Debug)]
   7 struct Foo(i32);
   8 impl Drop for Foo {
   9     fn drop(&mut self) {
  10         println!("{:?} dropped", self.0);
  11     }
  12 }
  13
  14 struct ConstainsDropField(Foo, Foo);
  15
  16 // Test that lint is triggered if a path that implements Drop is not captured by move
  17 fn test_precise_analysis_drop_paths_not_captured_by_move() {
  18     let t = ConstainsDropField(Foo(10), Foo(20));
  19
  20     let c = || {
  21         let _ = &t;
  22         //~^ ERROR: drop order
  23         //~| NOTE: for more information, see
  24         //~| HELP: add a dummy let to cause `t` to be fully captured
  25         let _t = t.0;
  26         //~^ NOTE: in Rust 2018, this closure captures all of `t`, but in Rust 2021, it will only capture `t.0`
  27         let _t = &t.1;
  28     };
  29
  30     c();
  31 }
  32 //~^ NOTE: in Rust 2018, `t` is dropped here, but in Rust 2021, only `t.0` will be dropped here as part of the closure
  33
  34 struct S;
  35 impl Drop for S {
  36     fn drop(&mut self) {}
  37 }
  38
  39 struct T(S, S);
  40 struct U(T, T);
  41
  42 // Test precise analysis for the lint works with paths longer than one.
  43 fn test_precise_analysis_long_path_missing() {
  44     let u = U(T(S, S), T(S, S));
  45
  46     let c = || {
  47         let _ = &u;
  48         //~^ ERROR: drop order
  49         //~| NOTE: for more information, see
  50         //~| HELP: add a dummy let to cause `u` to be fully captured
  51         let _x = u.0.0;
  52         //~^ NOTE: in Rust 2018, this closure captures all of `u`, but in Rust 2021, it will only capture `u.0.0`
  53         let _x = u.0.1;
  54         //~^ NOTE: in Rust 2018, this closure captures all of `u`, but in Rust 2021, it will only capture `u.0.1`
  55         let _x = u.1.0;
  56         //~^ NOTE: in Rust 2018, this closure captures all of `u`, but in Rust 2021, it will only capture `u.1.0`
  57     };
  58
  59     c();
  60 }
  61 //~^ NOTE: in Rust 2018, `u` is dropped here, but in Rust 2021, only `u.0.0` will be dropped here as part of the closure
  62 //~| NOTE: in Rust 2018, `u` is dropped here, but in Rust 2021, only `u.0.1` will be dropped here as part of the closure
  63 //~| NOTE: in Rust 2018, `u` is dropped here, but in Rust 2021, only `u.1.0` will be dropped here as part of the closure
  64
  65
  66 fn main() {
  67     test_precise_analysis_drop_paths_not_captured_by_move();
  68     test_precise_analysis_long_path_missing();
  69 }