error[E0505]: cannot move out of `value` because it is borrowed
  --> $DIR/if-let-guards-errors.rs:16:13
   |
LL |     let f = |x: &E| {
   |             ------- borrow of `*value` occurs here
LL |         match &x {
LL |             E::Number(_) if let E::Number(ref mut n) = *value => { }
   |                                                        ------ borrow occurs due to use in closure
...
LL |     let x = value;
   |             ^^^^^ move out of `value` occurs here
LL |
LL |     drop(f);
   |          - borrow later used here

error[E0382]: use of moved value: `value`
  --> $DIR/if-let-guards-errors.rs:28:13
   |
LL | fn if_let_move(value: Box<E>) {
   |                ----- move occurs because `value` has type `Box<E>`, which does not implement the `Copy` trait
LL |     let f = |x: &E| {
   |             ------- value moved into closure here
LL |         match &x {
LL |             E::Number(_) if let E::String(s) = *value => { }
   |                                                ------ variable moved due to use in closure
...
LL |     let x = value;
   |             ^^^^^ value used here after move

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0382, E0505.
For more information about an error, try `rustc --explain E0382`.