error[E0573]: expected type, found local variable `num`
  --> $DIR/let-binding-init-expr-as-ty.rs:2:27
   |
LL |     let foo: i32::from_be(num);
   |            --             ^^^ not a type
   |            |
   |            help: use `=` if you meant to assign

error[E0214]: parenthesized type parameters may only be used with a `Fn` trait
  --> $DIR/let-binding-init-expr-as-ty.rs:2:19
   |
LL |     let foo: i32::from_be(num);
   |                   ^^^^^^^^^^^^ only `Fn` traits may use parentheses
   |
help: use angle brackets instead
   |
LL |     let foo: i32::from_be<num>;
   |                          ~   ~

error[E0223]: ambiguous associated type
  --> $DIR/let-binding-init-expr-as-ty.rs:2:14
   |
LL |     let foo: i32::from_be(num);
   |              ^^^^^^^^^^^^^^^^^ help: use fully-qualified syntax: `<i32 as Trait>::from_be`

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0214, E0223, E0573.
For more information about an error, try `rustc --explain E0214`.