error[E0601]: `main` function not found in crate `ice_6250`
  --> $DIR/ice-6250.rs:16:2
   |
LL | }
   |  ^ consider adding a `main` function to `$DIR/ice-6250.rs`

error[E0308]: mismatched types
  --> $DIR/ice-6250.rs:12:14
   |
LL |     for reference in vec![1, 2, 3] {
   |         --------- expected due to the type of this binding
...
LL |         Some(reference) = cache.data.get(key) {
   |              ^^^^^^^^^ expected integer, found `&i32`
   |
help: consider dereferencing the borrow
   |
LL |         Some(*reference) = cache.data.get(key) {
   |              +

error[E0308]: mismatched types
  --> $DIR/ice-6250.rs:12:9
   |
LL |         Some(reference) = cache.data.get(key) {
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `bool`, found `()`
   |
help: consider adding `let`
   |
LL |         let Some(reference) = cache.data.get(key) {
   |         +++

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0308, E0601.
For more information about an error, try `rustc --explain E0308`.