error[E0308]: mismatched types
  --> $DIR/mut-ref-reassignment.rs:2:11
   |
LL | fn suggestion(opt: &mut Option<String>) {
   |                    ------------------- expected due to this parameter type
LL |     opt = None;
   |           ^^^^ expected `&mut Option<String>`, found `Option<_>`
   |
   = note: expected mutable reference `&mut Option<String>`
                           found enum `Option<_>`
help: consider dereferencing here to assign to the mutably borrowed value
   |
LL |     *opt = None;
   |     +

error[E0308]: mismatched types
  --> $DIR/mut-ref-reassignment.rs:6:11
   |
LL | fn no_suggestion(opt: &mut Result<String, ()>) {
   |                       ----------------------- expected due to this parameter type
LL |     opt = None
   |           ^^^^ expected `&mut Result<String, ()>`, found `Option<_>`
   |
   = note: expected mutable reference `&mut Result<String, ()>`
                           found enum `Option<_>`

error[E0308]: mismatched types
  --> $DIR/mut-ref-reassignment.rs:10:11
   |
LL | fn suggestion2(opt: &mut Option<String>) {
   |                     ------------------- expected due to this parameter type
LL |     opt = Some(String::new())
   |           ^^^^^^^^^^^^^^^^^^^ expected `&mut Option<String>`, found `Option<String>`
   |
   = note: expected mutable reference `&mut Option<String>`
                           found enum `Option<String>`
help: consider dereferencing here to assign to the mutably borrowed value
   |
LL |     *opt = Some(String::new())
   |     +

error[E0308]: mismatched types
  --> $DIR/mut-ref-reassignment.rs:14:11
   |
LL | fn no_suggestion2(opt: &mut Option<String>) {
   |                        ------------------- expected due to this parameter type
LL |     opt = Some(42)
   |           ^^^^^^^^ expected `&mut Option<String>`, found `Option<{integer}>`
   |
   = note: expected mutable reference `&mut Option<String>`
                           found enum `Option<{integer}>`

error: aborting due to 4 previous errors

For more information about this error, try `rustc --explain E0308`.