36 pub struct Operation(usize);  struct
38 impl Operation {  impl
45     pub fn hook<T>(r: &mut T) -> Operation {  in hook()
67     Operation(Operation),  enumerator
107     fn register(&self, oper: Operation, cx: &Context) -> bool;  in register()
110     fn unregister(&self, oper: Operation);  in unregister()
119     fn watch(&self, oper: Operation, cx: &Context) -> bool;  in watch()
122     fn unwatch(&self, oper: Operation);  in unwatch()
134     fn register(&self, oper: Operation, cx: &Context) -> bool {  in register()
138     fn unregister(&self, oper: Operation) {  in unregister()
150     fn watch(&self, oper: Operation, cx: &Context) -> bool {  in watch()
154     fn unwatch(&self, oper: Operation) {  in unwatch()