| 0,0 → 1,74 |
|---|
| #ifndef __refcount_h__ |
| #define __refcount_h__ |
| |
| #include "lispassert.h" |
| #include "yacasbase.h" |
| |
| //------------------------------------------------------------------------------ |
| // RefPtr - Smart pointer for (intrusive) reference counting. |
| // Simply, an object's reference count is the number of RefPtrs refering to it. |
| // The RefPtr will delete the referenced object when the count reaches zero. |
| |
| /*TODO: this might be improved a little by having RefPtr wrap the object being |
| pointed to so the user of RefPtr does not need to add ReferenceCount explicitly. |
| One can use RefPtr on any arbitrary object from that moment on. |
| */ |
| |
| typedef ReferenceType ReferenceCount; |
| |
| template<class T> |
| class RefPtr : public YacasBase // derived, so we can 'NEW LispPtr[nnn]' |
| { |
| public: |
| // Default constructor (not explicit, so it auto-initializes) |
| inline RefPtr() : iPtr(NULL) {} |
| // Construct from pointer to T |
| explicit RefPtr(T *ptr) : iPtr(ptr) { if (ptr) { ptr->iReferenceCount++; } } |
| // Copy constructor |
| RefPtr(const RefPtr &refPtr) : iPtr(refPtr.ptr()) { if (iPtr) { iPtr->iReferenceCount++; } } |
| // Destructor |
| ~RefPtr() |
| { |
| if (iPtr) |
| { |
| iPtr->iReferenceCount--; |
| if (iPtr->iReferenceCount == 0) |
| { |
| delete iPtr; |
| } |
| } |
| } |
| // Assignment from pointer |
| RefPtr &operator=(T *ptr) |
| { |
| if (ptr) |
| { |
| ptr->iReferenceCount++; |
| } |
| if (iPtr) |
| { |
| iPtr->iReferenceCount--; |
| if (iPtr->iReferenceCount == 0) |
| { |
| delete iPtr; |
| } |
| } |
| iPtr = ptr; |
| return *this; |
| } |
| // Assignment from another |
| RefPtr &operator=(const RefPtr &refPtr) { return this->operator=(refPtr.ptr()); } |
| |
| operator T*() const { return iPtr; } // implicit conversion to pointer to T |
| T &operator*() const { return *iPtr; } // so (*refPtr) is a reference to T |
| T *operator->() const { return iPtr; } // so (refPtr->member) accesses T's member |
| T *ptr() const { return iPtr; } // so (refPtr.ptr()) returns the pointer to T (boost calls this method 'get') |
| bool operator!() const { return !iPtr; } // is null pointer |
| |
| private: |
| T *iPtr; |
| }; |
| |
| |
| #endif |
| |