1 warning: captured variable cannot escape `FnMut` closure body
2 --> $DIR/issue-49824.rs:10:9
5 | - inferred to be a `FnMut` closure
10 LL | | let _y = &mut x;
12 | |_________^ returns a closure that contains a reference to a captured variable, which then escapes the closure body
14 = note: `FnMut` closures only have access to their captured variables while they are executing...
15 = note: ...therefore, they cannot allow references to captured variables to escape
16 = warning: this error has been downgraded to a warning for backwards compatibility with previous releases
17 = warning: this represents potential undefined behavior in your code and this warning will become a hard error in the future
18 = note: for more information, try `rustc --explain E0729`
20 error: compilation successful
21 --> $DIR/issue-49824.rs:6:1
32 error: aborting due to previous error