| warning: captured variable cannot escape `FnMut` closure body |
| --> $DIR/issue-40510-3.rs:18:9 |
| | |
| LL | || { |
| | - inferred to be a `FnMut` closure |
| LL | / || { |
| LL | | x.push(()) |
| LL | | } |
| | |_________^ returns a closure that contains a reference to a captured variable, which then escapes the closure body |
| | |
| = note: `FnMut` closures only have access to their captured variables while they are executing... |
| = note: ...therefore, they cannot allow references to captured variables to escape |
| = warning: This error has been downgraded to a warning for backwards compatibility with previous releases. |
| It represents potential unsoundness in your code. |
| This warning will become a hard error in the future. |
| |
