diff options
| -rw-r--r-- | indra/llcommon/llpointer.h | 53 |
1 files changed, 25 insertions, 28 deletions
diff --git a/indra/llcommon/llpointer.h b/indra/llcommon/llpointer.h index bbe3595435..c5dd5532cc 100644 --- a/indra/llcommon/llpointer.h +++ b/indra/llcommon/llpointer.h @@ -28,6 +28,7 @@ #include "llerror.h" // *TODO: consider eliminating this #include "llmutex.h" +#include <utility> // std::swap() //---------------------------------------------------------------------------- // RefCount objects should generally only be accessed by way of LLPointer<>'s @@ -118,24 +119,26 @@ public: LLPointer<Type>& operator =(Type* ptr) { - assign(ptr); + // copy-and-swap idiom, see http://gotw.ca/gotw/059.htm + LLPointer temp(ptr); + using std::swap; // per Swappable convention + swap(*this, temp); return *this; } LLPointer<Type>& operator =(const LLPointer<Type>& ptr) { - assign(ptr); + LLPointer temp(ptr); + using std::swap; // per Swappable convention + swap(*this, temp); return *this; } LLPointer<Type>& operator =(LLPointer<Type>&& ptr) { - if (mPointer != ptr.mPointer) - { - unref(); - mPointer = ptr.mPointer; - ptr.mPointer = nullptr; - } + LLPointer temp(std::move(ptr)); + using std::swap; // per Swappable convention + swap(*this, temp); return *this; } @@ -143,28 +146,32 @@ public: template<typename Subclass> LLPointer<Type>& operator =(const LLPointer<Subclass>& ptr) { - assign(ptr.get()); + LLPointer temp(ptr); + using std::swap; // per Swappable convention + swap(*this, temp); return *this; } template<typename Subclass> LLPointer<Type>& operator =(LLPointer<Subclass>&& ptr) { - if (mPointer != ptr.mPointer) - { - unref(); - mPointer = ptr.mPointer; - ptr.mPointer = nullptr; - } + LLPointer temp(std::move(ptr)); + using std::swap; // per Swappable convention + swap(*this, temp); return *this; } // Just exchange the pointers, which will not change the reference counts. static void swap(LLPointer<Type>& a, LLPointer<Type>& b) { - Type* temp = a.mPointer; - a.mPointer = b.mPointer; - b.mPointer = temp; + using std::swap; // per Swappable convention + swap(a.mPointer, b.mPointer); + } + + // Put swap() overload in the global namespace, per Swappable convention + friend void swap(LLPointer<Type>& a, LLPointer<Type>& b) + { + LLPointer<Type>::swap(a, b); } protected: @@ -196,16 +203,6 @@ protected: } #endif // LL_LIBRARY_INCLUDE - void assign(const LLPointer<Type>& ptr) - { - if (mPointer != ptr.mPointer) - { - unref(); - mPointer = ptr.mPointer; - ref(); - } - } - protected: Type* mPointer; }; |