error[E0387]: cannot assign to data in a captured outer variable in an `Fn` closure
  --> $DIR/borrow-immutable-upvar-mutation.rs:15:27
   |
LL |         let _f = to_fn(|| x = 42); //~ ERROR cannot assign
   |                           ^^^^^^
   |
help: consider changing this closure to take self by mutable reference
  --> $DIR/borrow-immutable-upvar-mutation.rs:15:24
   |
LL |         let _f = to_fn(|| x = 42); //~ ERROR cannot assign
   |                        ^^^^^^^^^

error[E0387]: cannot borrow data mutably in a captured outer variable in an `Fn` closure
  --> $DIR/borrow-immutable-upvar-mutation.rs:18:36
   |
LL |         let _g = to_fn(|| set(&mut y)); //~ ERROR cannot borrow
   |                                    ^
   |
help: consider changing this closure to take self by mutable reference
  --> $DIR/borrow-immutable-upvar-mutation.rs:18:24
   |
LL |         let _g = to_fn(|| set(&mut y)); //~ ERROR cannot borrow
   |                        ^^^^^^^^^^^^^^

error[E0387]: cannot assign to data in a captured outer variable in an `Fn` closure
  --> $DIR/borrow-immutable-upvar-mutation.rs:21:55
   |
LL |         let _h = to_fn_mut(|| { set(&mut z); to_fn(|| z = 42); }); //~ ERROR cannot assign
   |                                                       ^^^^^^
   |
help: consider changing this closure to take self by mutable reference
  --> $DIR/borrow-immutable-upvar-mutation.rs:21:52
   |
LL |         let _h = to_fn_mut(|| { set(&mut z); to_fn(|| z = 42); }); //~ ERROR cannot assign
   |                                                    ^^^^^^^^^

error[E0594]: cannot assign to captured outer variable in an `Fn` closure
  --> $DIR/borrow-immutable-upvar-mutation.rs:27:32
   |
LL |         let _f = to_fn(move || x = 42); //~ ERROR cannot assign
   |                                ^^^^^^
   |
   = note: `Fn` closures cannot capture their enclosing environment for modifications
help: consider changing this closure to take self by mutable reference
  --> $DIR/borrow-immutable-upvar-mutation.rs:27:24
   |
LL |         let _f = to_fn(move || x = 42); //~ ERROR cannot assign
   |                        ^^^^^^^^^^^^^^

error[E0596]: cannot borrow captured outer variable in an `Fn` closure as mutable
  --> $DIR/borrow-immutable-upvar-mutation.rs:30:41
   |
LL |         let _g = to_fn(move || set(&mut y)); //~ ERROR cannot borrow
   |                                         ^
   |
help: consider changing this closure to take self by mutable reference
  --> $DIR/borrow-immutable-upvar-mutation.rs:30:24
   |
LL |         let _g = to_fn(move || set(&mut y)); //~ ERROR cannot borrow
   |                        ^^^^^^^^^^^^^^^^^^^

error[E0594]: cannot assign to captured outer variable in an `Fn` closure
  --> $DIR/borrow-immutable-upvar-mutation.rs:33:65
   |
LL |         let _h = to_fn_mut(move || { set(&mut z); to_fn(move || z = 42); }); //~ ERROR cannot assign
   |                                                                 ^^^^^^
   |
   = note: `Fn` closures cannot capture their enclosing environment for modifications
help: consider changing this closure to take self by mutable reference
  --> $DIR/borrow-immutable-upvar-mutation.rs:33:57
   |
LL |         let _h = to_fn_mut(move || { set(&mut z); to_fn(move || z = 42); }); //~ ERROR cannot assign
   |                                                         ^^^^^^^^^^^^^^

error: aborting due to 6 previous errors

Some errors occurred: E0387, E0594, E0596.
For more information about an error, try `rustc --explain E0387`.