error[E0382]: use of moved value: `my_str`
  --> $DIR/borrowck-drop-from-guard.rs:22:23
   |
LL |         Some(_) if { drop(my_str); false } => {}
   |                           ------ value moved here
LL |         Some(_) => {}
LL |         None => { foo(my_str); } //~ ERROR [E0382]
   |                       ^^^^^^ value used here after move
   |
   = note: move occurs because `my_str` has type `std::string::String`, which does not implement the `Copy` trait

error: aborting due to previous error

For more information about this error, try `rustc --explain E0382`.