GeometryCommonDetAlgo/interface/DeepCopyPointerByClone.h

0001 #ifndef DeepCopyPointerByClone_H
0002 #define DeepCopyPointerByClone_H
0003
0004 #include <algorithm>
0005 #include <cassert>
0006
0007 /** Same as DeepCopyPointer, except that it copies the object
0008  *  pointed to using the clone() virtual copy constructor.
0009  */
0010
0011 template <class T>
0012 class DeepCopyPointerByClone {
0013 public:
0014   ~DeepCopyPointerByClone() { delete theData; }
0015   DeepCopyPointerByClone() : theData(nullptr) {}
0016
0017   DeepCopyPointerByClone(T* t) : theData(t) {}
0018
0019   DeepCopyPointerByClone(const DeepCopyPointerByClone& other) {
0020     if (other.theData)
0021       theData = other->clone();
0022     else
0023       theData = nullptr;
0024   }
0025
0026   DeepCopyPointerByClone& operator=(const DeepCopyPointerByClone& other) {
0027     if (theData != other.theData) {
0028       delete theData;
0029       if (other.theData)
0030         theData = other->clone();
0031       else
0032         theData = 0;
0033     }
0034     return *this;
0035   }
0036
0037   // straight from http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2027.html
0038   DeepCopyPointerByClone(DeepCopyPointerByClone&& other) : theData(other.theData) { other.theData = nullptr; }
0039   DeepCopyPointerByClone& operator=(DeepCopyPointerByClone&& other) {
0040     std::swap(theData, other.theData);
0041     return *this;
0042   }
0043
0044   T& operator*() {
0045     assert(theData);
0046     return *theData;
0047   }
0048   const T& operator*() const {
0049     assert(theData);
0050     return *theData;
0051   }
0052
0053   T* operator->() {
0054     assert(theData);
0055     return theData;
0056   }
0057   const T* operator->() const {
0058     assert(theData);
0059     return theData;
0060   }
0061
0062   /// to allow test like " if (p) {...}"
0063   operator bool() const { return theData != 0; }
0064
0065   /// to allow test like " if (p == &someT) {...}"
0066   bool operator==(const T* otherP) const { return theData == otherP; }
0067
0068 private:
0069   T* theData;
0070 };
0071
0072 #endif  // DeepCopyPointerByClone_H