diff options
| -rw-r--r-- | common/ptr.h | 47 |
1 files changed, 39 insertions, 8 deletions
diff --git a/common/ptr.h b/common/ptr.h index 1121ffd665..a9598e5914 100644 --- a/common/ptr.h +++ b/common/ptr.h @@ -29,6 +29,28 @@ namespace Common { +class SharedPtrDeletionInternal { +public: + virtual ~SharedPtrDeletionInternal() {} +}; + +template<class T> +class SharedPtrDeletionImpl : public SharedPtrDeletionInternal { +public: + SharedPtrDeletionImpl(T *ptr) : _ptr(ptr) {} + ~SharedPtrDeletionImpl() { + // Checks if the supplied type is not just a plain + // forward definition, taken from boost::checked_delete + // This makes the user really aware what he tries to do + // when using this with an incomplete type. + typedef char completeCheck[sizeof(T) ? 1 : -1]; + (void)sizeof(completeCheck); + delete _ptr; + } +private: + T *_ptr; +}; + /** * A simple shared pointer implementation modelled after boost. * @@ -56,8 +78,11 @@ namespace Common { * for arrays! * * Note that you have to specify the type itself not the pointer type as - * template parameter. You also need to have a real definition of the type - * you want to use, a simple forward definition is not enough. + * template parameter. + * + * When creating a SharedPtr object from a normal pointer you need a real + * definition of the type you want SharedPtr to manage, a simple forward + * definition is not enough. * * The class has implicit upcast support, so if you got a class B derived * from class A, you can assign a pointer to B without any problems to a @@ -65,7 +90,8 @@ namespace Common { * assignment of a SharedPtr<B> object to a SharedPtr<A> object. * * There are also operators != and == to compare two SharedPtr objects - * with compatible pointers. + * with compatible pointers. Comparision between a SharedPtr object and + * a plain pointer is just possible via SharedPtr::get. */ template<class T> class SharedPtr { @@ -74,11 +100,11 @@ public: typedef T ValueType; typedef T *Pointer; - SharedPtr() : _refCount(0), _pointer(0) {} - template<class T2> explicit SharedPtr(T2 *p) : _refCount(new RefValue(1)), _pointer(p) {} + SharedPtr() : _refCount(0), _deletion(0), _pointer(0) {} + template<class T2> explicit SharedPtr(T2 *p) : _refCount(new RefValue(1)), _deletion(new SharedPtrDeletionImpl<T2>(p)), _pointer(p) {} - SharedPtr(const SharedPtr &r) : _refCount(r._refCount), _pointer(r._pointer) { if (_refCount) ++(*_refCount); } - template<class T2> SharedPtr(const SharedPtr<T2> &r) : _refCount(r._refCount), _pointer(r._pointer) { if (_refCount) ++(*_refCount); } + SharedPtr(const SharedPtr &r) : _refCount(r._refCount), _deletion(r._deletion), _pointer(r._pointer) { if (_refCount) ++(*_refCount); } + template<class T2> SharedPtr(const SharedPtr<T2> &r) : _refCount(r._refCount), _deletion(r._deletion), _pointer(r._pointer) { if (_refCount) ++(*_refCount); } ~SharedPtr() { decRef(); } @@ -88,6 +114,7 @@ public: decRef(); _refCount = r._refCount; + _deletion = r._deletion; _pointer = r._pointer; return *this; @@ -100,6 +127,7 @@ public: decRef(); _refCount = r._refCount; + _deletion = r._deletion; _pointer = r._pointer; return *this; @@ -140,7 +168,8 @@ private: --(*_refCount); if (!*_refCount) { delete _refCount; - delete _pointer; + delete _deletion; + _deletion = 0; _refCount = 0; _pointer = 0; } @@ -148,6 +177,7 @@ private: } RefValue *_refCount; + SharedPtrDeletionInternal *_deletion; T *_pointer; }; @@ -166,3 +196,4 @@ bool operator !=(const Common::SharedPtr<T1> &l, const Common::SharedPtr<T2> &r) #endif + |