src/test/ui/issues/issue-21600.stderr

   1 error[E0596]: cannot borrow `x` as mutable, as it is a captured variable in a `Fn` closure
   2   --> $DIR/issue-21600.rs:14:20
   3    |
   4 LL | fn call_it<F>(f: F) where F: Fn() { f(); }
   5    |                  - change this to accept `FnMut` instead of `Fn`
   6 ...
   7 LL |         call_it(|| x.gen_mut());
   8    |         -------    ^^^^^^^^^^^ cannot borrow as mutable
   9    |         |
  10    |         expects `Fn` instead of `FnMut`
  11
  12 error[E0596]: cannot borrow `x` as mutable, as it is a captured variable in a `Fn` closure
  13   --> $DIR/issue-21600.rs:14:17
  14    |
  15 LL |   fn call_it<F>(f: F) where F: Fn() { f(); }
  16    |                    - change this to accept `FnMut` instead of `Fn`
  17 ...
  18 LL |       call_it(|| {
  19    |  _____-------_-
  20    | |     |
  21    | |     expects `Fn` instead of `FnMut`
  22 LL | |         call_it(|| x.gen());
  23 LL | |         call_it(|| x.gen_mut());
  24    | |                 ^^ - mutable borrow occurs due to use of `x` in closure
  25    | |                 |
  26    | |                 cannot borrow as mutable
  27 LL | |
  28 LL | |
  29 LL | |     });
  30    | |_____- in this closure
  31
  32 error: aborting due to 2 previous errors
  33
  34 For more information about this error, try `rustc --explain E0596`.