Return true if `state != s`:
| 259 | const T get() { return state.get(ref); } |
| 260 | // Return true if `state != s`: |
| 261 | bool cmp(const S &s) const { return state.cmp(s); } |
| 262 | |
| 263 | // Optional function for reverse iteration: |
| 264 | void prev() { state.prev(ref); } |