error[E0624]: method `foo` is private
  --> $DIR/private-impl-method.rs:20:7
   |
LL |         fn foo(&self) {}
   |         ------------- private method defined here
...
LL |     s.foo();
   |       ^^^ private method

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0624`.