| //@ edition:2021 |
| |
| #![feature(rustc_attrs)] |
| #![allow(unused)] |
| |
| struct Point { |
| x: i32, |
| y: i32, |
| } |
| struct Wrapper { |
| p: Point, |
| } |
| |
| fn main() { |
| let mut w = Wrapper { p: Point { x: 10, y: 10 } }; |
| |
| // Only paths that appears within the closure that directly start off |
| // a variable defined outside the closure are captured. |
| // |
| // Therefore `w.p` is captured |
| // Note that `wp.x` doesn't start off a variable defined outside the closure. |
| let c = #[rustc_capture_analysis] |
| //~^ ERROR: attributes on expressions are experimental |
| //~| NOTE: see issue #15701 <https://github.com/rust-lang/rust/issues/15701> |
| //~| NOTE: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date |
| || { |
| //~^ ERROR: First Pass analysis includes: |
| //~| ERROR: Min Capture analysis includes: |
| let wp = &w.p; |
| //~^ NOTE: Capturing w[(0, 0)] -> ImmBorrow |
| //~| NOTE: Min Capture w[(0, 0)] -> ImmBorrow |
| println!("{}", wp.x); |
| }; |
| |
| // Since `c` captures `w.p` by an ImmBorrow, `w.p.y` can't be mutated. |
| let py = &mut w.p.y; |
| c(); |
| |
| *py = 20 |
| } |