// 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 } }; let c = #[rustc_capture_analysis] //~^ ERROR: attributes on expressions are experimental //~| NOTE: see issue #15701 //~| NOTE: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date || { //~^ ERROR: First Pass analysis includes: //~| ERROR: Min Capture analysis includes: println!("{}", w.p.x); //~^ NOTE: Capturing w[(0, 0),(0, 0)] -> ImmBorrow //~| NOTE: Min Capture w[(0, 0),(0, 0)] -> ImmBorrow }; // `c` only captures `w.p.x`, therefore it's safe to mutate `w.p.y`. let py = &mut w.p.y; c(); *py = 20 }