error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
  --> $DIR/unstable-const-fn-in-libcore.rs:24:26
   |
LL |             Opt::None => f(),
   |                          ^^^

error[E0493]: destructors cannot be evaluated at compile-time
  --> $DIR/unstable-const-fn-in-libcore.rs:19:53
   |
LL |     const fn unwrap_or_else<F: FnOnce() -> T>(self, f: F) -> T {
   |                                                     ^ constant functions cannot evaluate destructors
...
LL |     }
   |     - value is dropped here

error[E0493]: destructors cannot be evaluated at compile-time
  --> $DIR/unstable-const-fn-in-libcore.rs:19:47
   |
LL |     const fn unwrap_or_else<F: FnOnce() -> T>(self, f: F) -> T {
   |                                               ^^^^ constant functions cannot evaluate destructors
...
LL |     }
   |     - value is dropped here

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0015, E0493.
For more information about an error, try `rustc --explain E0015`.