rust/tests/ui/closures/2229_closure_analysis/run_pass/multilevel-path-1.rs
2023-01-11 09:32:08 +00:00

34 lines
727 B
Rust

// edition:2021
// run-pass
// Test that closures can capture paths that are more precise than just one level
// from the root variable.
//
// If the closures can handle such precision we should be able to mutate one path in the closure
// while being able to mutate another path outside the closure, where the two paths are disjoint
// after applying two projections on the root variable.
#![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 mut c = || {
w.p.x += 20;
};
// `c` only captures `w.p.x`, therefore it's safe to mutate `w.p.y`.
let py = &mut w.p.y;
c();
*py = 20
}