diff options
Diffstat (limited to 'indra/llcommon')
| -rw-r--r-- | indra/llcommon/llpointer.h | 256 |
1 files changed, 55 insertions, 201 deletions
diff --git a/indra/llcommon/llpointer.h b/indra/llcommon/llpointer.h index 048547e4cc..71c955c4c5 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 @@ -60,6 +61,13 @@ public: ref(); } + // Even though the template constructors below accepting + // (const LLPointer<Subclass>&) and (LLPointer<Subclass>&&) appear to + // subsume these specific (const LLPointer<Type>&) and (LLPointer<Type>&&) + // constructors, the compiler recognizes these as The Copy Constructor and + // The Move Constructor, respectively. In other words, even in the + // presence of the LLPointer<Subclass> constructors, we still must specify + // the LLPointer<Type> constructors. LLPointer(const LLPointer<Type>& ptr) : mPointer(ptr.mPointer) { @@ -105,32 +113,46 @@ public: bool notNull() const { return (mPointer != nullptr); } operator Type*() const { return mPointer; } - bool operator !=(Type* ptr) const { return (mPointer != ptr); } - bool operator ==(Type* ptr) const { return (mPointer == ptr); } - bool operator ==(const LLPointer<Type>& ptr) const { return (mPointer == ptr.mPointer); } - bool operator < (const LLPointer<Type>& ptr) const { return (mPointer < ptr.mPointer); } - bool operator > (const LLPointer<Type>& ptr) const { return (mPointer > ptr.mPointer); } + template <typename Type1> + bool operator !=(Type1* ptr) const { return (mPointer != ptr); } + template <typename Type1> + bool operator ==(Type1* ptr) const { return (mPointer == ptr); } + template <typename Type1> + bool operator !=(const LLPointer<Type1>& ptr) const { return (mPointer != ptr.mPointer); } + template <typename Type1> + bool operator ==(const LLPointer<Type1>& ptr) const { return (mPointer == ptr.mPointer); } + bool operator < (const LLPointer<Type>& ptr) const { return (mPointer < ptr.mPointer); } + bool operator > (const LLPointer<Type>& ptr) const { return (mPointer > ptr.mPointer); } 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; } + // Even though the template assignment operators below accepting + // (const LLPointer<Subclass>&) and (LLPointer<Subclass>&&) appear to + // subsume these specific (const LLPointer<Type>&) and (LLPointer<Type>&&) + // assignment operators, the compiler recognizes these as Copy Assignment + // and Move Assignment, respectively. In other words, even in the presence + // of the LLPointer<Subclass> assignment operators, we still must specify + // the LLPointer<Type> operators. 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; } @@ -138,28 +160,32 @@ 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: @@ -191,184 +217,12 @@ protected: } #endif // LL_LIBRARY_INCLUDE - void assign(const LLPointer<Type>& ptr) - { - if (mPointer != ptr.mPointer) - { - unref(); - mPointer = ptr.mPointer; - ref(); - } - } - protected: Type* mPointer; }; -template <class Type> class LLConstPointer -{ - template<typename Subclass> - friend class LLConstPointer; -public: - LLConstPointer() : - mPointer(nullptr) - { - } - - LLConstPointer(const Type* ptr) : - mPointer(ptr) - { - ref(); - } - - LLConstPointer(const LLConstPointer<Type>& ptr) : - mPointer(ptr.mPointer) - { - ref(); - } - - LLConstPointer(LLConstPointer<Type>&& ptr) noexcept - { - mPointer = ptr.mPointer; - ptr.mPointer = nullptr; - } - - // support conversion up the type hierarchy. See Item 45 in Effective C++, 3rd Ed. - template<typename Subclass> - LLConstPointer(const LLConstPointer<Subclass>& ptr) : - mPointer(ptr.get()) - { - ref(); - } - - template<typename Subclass> - LLConstPointer(LLConstPointer<Subclass>&& ptr) noexcept : - mPointer(ptr.get()) - { - ptr.mPointer = nullptr; - } - - ~LLConstPointer() - { - unref(); - } - - const Type* get() const { return mPointer; } - const Type* operator->() const { return mPointer; } - const Type& operator*() const { return *mPointer; } - - operator BOOL() const { return (mPointer != nullptr); } - operator bool() const { return (mPointer != nullptr); } - bool operator!() const { return (mPointer == nullptr); } - bool isNull() const { return (mPointer == nullptr); } - bool notNull() const { return (mPointer != nullptr); } - - operator const Type*() const { return mPointer; } - bool operator !=(const Type* ptr) const { return (mPointer != ptr); } - bool operator ==(const Type* ptr) const { return (mPointer == ptr); } - bool operator ==(const LLConstPointer<Type>& ptr) const { return (mPointer == ptr.mPointer); } - bool operator < (const LLConstPointer<Type>& ptr) const { return (mPointer < ptr.mPointer); } - bool operator > (const LLConstPointer<Type>& ptr) const { return (mPointer > ptr.mPointer); } - - LLConstPointer<Type>& operator =(const Type* ptr) - { - if( mPointer != ptr ) - { - unref(); - mPointer = ptr; - ref(); - } - - return *this; - } - - LLConstPointer<Type>& operator =(const LLConstPointer<Type>& ptr) - { - if( mPointer != ptr.mPointer ) - { - unref(); - mPointer = ptr.mPointer; - ref(); - } - return *this; - } - - LLConstPointer<Type>& operator =(LLConstPointer<Type>&& ptr) - { - if (mPointer != ptr.mPointer) - { - unref(); - mPointer = ptr.mPointer; - ptr.mPointer = nullptr; - } - return *this; - } - - // support assignment up the type hierarchy. See Item 45 in Effective C++, 3rd Ed. - template<typename Subclass> - LLConstPointer<Type>& operator =(const LLConstPointer<Subclass>& ptr) - { - if( mPointer != ptr.get() ) - { - unref(); - mPointer = ptr.get(); - ref(); - } - return *this; - } - - template<typename Subclass> - LLConstPointer<Type>& operator =(LLConstPointer<Subclass>&& ptr) - { - if (mPointer != ptr.mPointer) - { - unref(); - mPointer = ptr.mPointer; - ptr.mPointer = nullptr; - } - return *this; - } - - // Just exchange the pointers, which will not change the reference counts. - static void swap(LLConstPointer<Type>& a, LLConstPointer<Type>& b) - { - const Type* temp = a.mPointer; - a.mPointer = b.mPointer; - b.mPointer = temp; - } - -protected: -#ifdef LL_LIBRARY_INCLUDE - void ref(); - void unref(); -#else // LL_LIBRARY_INCLUDE - void ref() - { - if (mPointer) - { - mPointer->ref(); - } - } - - void unref() - { - if (mPointer) - { - const Type *temp = mPointer; - mPointer = nullptr; - temp->unref(); - if (mPointer != nullptr) - { - LL_WARNS() << "Unreference did assignment to non-NULL because of destructor" << LL_ENDL; - unref(); - } - } - } -#endif // LL_LIBRARY_INCLUDE - -protected: - const Type* mPointer; -}; +template <typename Type> +using LLConstPointer = LLPointer<const Type>; template<typename Type> class LLCopyOnWritePointer : public LLPointer<Type> @@ -418,14 +272,14 @@ private: bool mStayUnique; }; -template<typename Type> -bool operator!=(Type* lhs, const LLPointer<Type>& rhs) +template<typename Type0, typename Type1> +bool operator!=(Type0* lhs, const LLPointer<Type1>& rhs) { return (lhs != rhs.get()); } -template<typename Type> -bool operator==(Type* lhs, const LLPointer<Type>& rhs) +template<typename Type0, typename Type1> +bool operator==(Type0* lhs, const LLPointer<Type1>& rhs) { return (lhs == rhs.get()); } |