ideletenotice.h

#pragma once
 
#include <cassert>
 
namespace itasca {
 class IThing;
 
 // Note: This class does not auto-remove itself on destruction!
 class IDeleteNotice {
 public:
 inline IDeleteNotice() { }
 virtual inline ~IDeleteNotice() { assert(next_ == nullptr); assert(prev_ == nullptr); }
 virtual void onDelete(IThing *pnt)=0;
 virtual void changeToNewPointer(IThing *oldPnt,IThing *newPnt)=0;
 inline void insert(IDeleteNotice **head);
 inline void remove(IDeleteNotice **head);
 inline bool isInserted() const { return next_ ? true : false; }
 inline IDeleteNotice *nextDeleteNotice() { return next_; }
 private:
 IDeleteNotice(const IDeleteNotice &) = delete;
 IDeleteNotice(IDeleteNotice &&) = delete;
 void operator=(const IDeleteNotice &) = delete;
 IDeleteNotice *next_ = nullptr;
 IDeleteNotice *prev_ = nullptr;
 };
 
 inline void IDeleteNotice::insert(IDeleteNotice **head) {
 assert(prev_==nullptr);
 assert(next_==nullptr);
 assert(head);
 next_ = *head;
 if (*head) (*head)->prev_ = this;
 *head = this;
 }
 
 inline void IDeleteNotice::remove(IDeleteNotice **head) {
 assert(head);
 if (prev_) prev_->next_ = next_;
 else if (*head==this) *head = next_;
 if (next_) next_->prev_ = prev_;
 next_ = prev_ = nullptr;
 }
 
} // namespace itasca
// EoF