src/test/ui/closures/2229_closure_analysis/migrations/migrations_rustfix.rs

   1 // run-rustfix
   2 #![deny(rust_2021_incompatible_closure_captures)]
   3 //~^ NOTE: the lint level is defined here
   4
   5 // Test the two possible cases for automated migartion using rustfix
   6 // - Closure contains a block i.e.  `|| { .. };`
   7 // - Closure contains just an expr `|| ..;`
   8
   9 #[derive(Debug)]
  10 struct Foo(i32);
  11 impl Drop for Foo {
  12     fn drop(&mut self) {
  13         println!("{:?} dropped", self.0);
  14     }
  15 }
  16
  17 fn closure_contains_block() {
  18     let t = (Foo(0), Foo(0));
  19     let c = || {
  20         //~^ ERROR: drop order
  21         //~| NOTE: for more information, see
  22         //~| HELP: add a dummy let to cause `t` to be fully captured
  23         let _t = t.0;
  24         //~^ NOTE: in Rust 2018, this closure captures all of `t`, but in Rust 2021, it will only capture `t.0`
  25     };
  26
  27     c();
  28 }
  29 //~^ NOTE: in Rust 2018, `t` is dropped here, but in Rust 2021, only `t.0` will be dropped here as part of the closure
  30
  31 fn closure_doesnt_contain_block() {
  32     let t = (Foo(0), Foo(0));
  33     let c = || t.0;
  34     //~^ ERROR: drop order
  35     //~| NOTE: in Rust 2018, this closure captures all of `t`, but in Rust 2021, it will only capture `t.0`
  36     //~| NOTE: for more information, see
  37     //~| HELP: add a dummy let to cause `t` to be fully captured
  38
  39     c();
  40 }
  41 //~^ NOTE: in Rust 2018, `t` is dropped here, but in Rust 2021, only `t.0` will be dropped here as part of the closure
  42
  43 fn main() {
  44     closure_contains_block();
  45     closure_doesnt_contain_block();
  46 }