tests/ui/regions/regions-return-ref-to-upvar-issue-17403.stderr

   1 error: captured variable cannot escape `FnMut` closure body
   2   --> $DIR/regions-return-ref-to-upvar-issue-17403.rs:7:24
   3    |
   4 LL |         let mut x = 0;
   5    |             ----- variable defined here
   6 LL |         let mut f = || &mut x;
   7    |                      - ^^^^^-
   8    |                      | |    |
   9    |                      | |    variable captured here
  10    |                      | returns a reference to a captured variable which escapes the closure body
  11    |                      inferred to be a `FnMut` closure
  12    |
  13    = note: `FnMut` closures only have access to their captured variables while they are executing...
  14    = note: ...therefore, they cannot allow references to captured variables to escape
  15
  16 error: aborting due to previous error
  17