add vcglib

vcglib/apps/unsupported/pivoting/ring.h

@@ -0,0 +1,129 @@
+#ifndef RING_H
+#define RING_H
+// Making a "ring" data structure from the STL
+#include <list>
+using namespace std;
+
+template<class T>
+class ring {
+  list<T> lst;
+public:
+
+  ring &operator=(const ring *r) {
+     lst = r->lst;
+  }
+  // Declaration necessary so the following 
+  // 'friend' statement sees this 'iterator' 
+  // instead of std::iterator:
+  class iterator;
+  friend class iterator;
+  class iterator : 
+     public std::iterator<std::bidirectional_iterator_tag, T, ptrdiff_t> {
+
+   public:
+    typename list<T>::iterator it;
+    list<T>* r;
+
+    
+    // "typename" necessary to resolve nesting:
+
+    iterator(): r(NULL) {}
+    iterator(list<T>& lst, const typename list<T>::iterator& i)
+        : r(&lst), it(i) {}
+
+    iterator &operator=(const iterator& x) {
+       it = x.it;
+       r = x.r;
+       return *this;
+    }
+
+    bool operator==(const iterator& x) const {
+      return it == x.it;
+    }
+
+    bool operator!=(const iterator& x) const {
+      return !(*this == x);
+    }
+
+    typename list<T>::reference operator*() const {
+      return *it;
+    }
+
+    iterator& operator++() {
+      ++it;
+      if(it == r->end())
+        it = r->begin();
+      return *this;
+    }
+
+    iterator operator++(int) {
+      iterator tmp = *this;
+      ++*this;
+      return tmp;
+    }
+
+    iterator& operator--() {
+      if(it == r->begin())
+        it = r->end();
+      --it;
+      return *this;
+    }
+
+    iterator operator--(int) {
+      iterator tmp = *this;
+      --*this; 
+      return tmp;
+    }
+
+    iterator operator+(int i) {
+      iterator tmp = *this;
+      while(i--) ++tmp;
+      return tmp;
+    }
+
+    iterator operator-(int i) {
+      iterator tmp = *this;
+      while(i--) --tmp;
+      return tmp;
+    }
+
+    iterator insert(const T& x){
+      return iterator(*r, r->insert(it, x));
+    }
+    
+    iterator erase() {
+      iterator tmp = iterator(*r, r->erase(it));
+      
+      if (tmp.it == r->end()) tmp.it = r->begin();
+
+      return tmp;
+    }
+  };
+  
+  iterator insert(iterator &i, const T& x) {
+    typename list<T>::iterator it;
+    it = lst.insert(i.it, x);
+    return iterator(lst, it);
+  }
+
+  iterator push_back(const T& x) {
+    typename list<T>::iterator it;
+    it = lst.insert(lst.end(), x);
+    return iterator(lst, it);
+    
+  }
+ /* void push_back(const T& x) {
+    lst.push_back(x);
+  }*/
+  
+  iterator begin() {
+    return iterator(lst, lst.begin());
+  }
+  
+  int size() { return lst.size(); }
+  void clear() { lst.clear(); }
+  void reverse() { lst.reverse(); }
+  void erase(iterator &i) { lst.erase(i.it); }
+};
+
+#endif