error[E0007]: cannot bind by-move with sub-bindings
  --> $DIR/E0007.rs:6:9
   |
LL |         op_string @ Some(s) => {},
   |         ^^^^^^^^^^^^^^^^^^^ binds an already bound by-move value by moving it

error[E0382]: use of moved value
  --> $DIR/E0007.rs:6:26
   |
LL |     let x = Some("s".to_string());
   |         - move occurs because `x` has type `std::option::Option<std::string::String>`, which does not implement the `Copy` trait
LL |     match x {
LL |         op_string @ Some(s) => {},
   |         -----------------^-
   |         |                |
   |         |                value used here after move
   |         value moved here

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0007, E0382.
For more information about an error, try `rustc --explain E0007`.