Drop copyright and license notices from source files

[libs/core.git] / source / core / refptr.h

diff --git a/source/core/refptr.h b/source/core/refptr.h
index ee020e0eb8783f3af6579f8960b4ae1707b9b18d..d245b34a7e90bab8fb14f5e26cc691a1385f761c 100644 (file)
--- a/source/core/refptr.h
+++ b/source/core/refptr.h
@@ -1,53 +1,105 @@
-/* $Id$
-
-This file is part of libmspcore
-Copyright © 2006-2007 Mikko Rasa, Mikkosoft Productions
-Distributed under the LGPL
-*/
 #ifndef MSP_CORE_REFPTR_H_
 #define MSP_CORE_REFPTR_H_
 
 namespace Msp {
 
+/**
+A reference counting smart pointer.  When the last RefPtr for the data gets
+destroyed, the data is deleted as well.
+*/
 template<typename T>
 class RefPtr
 {
+       template<typename U> friend class RefPtr;
+
+private:
+       enum
+       {
+               KEEP = 1U<<(sizeof(unsigned)*8-1)
+       };
+
+       T *data;
+       unsigned *count;
+
 public:
        RefPtr(): data(0), count(0) { }
-       RefPtr(T *d): data(d), count(0) { if(data) count=new unsigned(1); }
+       RefPtr(T *d): data(d), count(data ? new unsigned(1) : 0) { }
+private:
+       RefPtr(T *d, unsigned *c): data(d), count(d ? c : 0) { incref(); }
+
+public:
+       /* Must have this or the compiler will generate a default copy-c'tor despite
+       the template version */
        RefPtr(const RefPtr &p): data(p.data), count(p.count) { incref(); }
+
+       template<typename U>
+       RefPtr(const RefPtr<U> &p): data(p.data), count(p.count) { incref(); }
+
        ~RefPtr() { decref(); }
 
-       RefPtr &operator=(const RefPtr &p)
+       RefPtr &operator=(T *d)
+       {
+               decref();
+               data = d;
+               count = (d ? new unsigned(1) : 0);
+               return *this;
+       }
+
+       // Likewise for the assignment operator
+       RefPtr &operator=(const RefPtr &p) { return assign(p); }
+
+       template<typename U>
+       RefPtr &operator=(const RefPtr<U> &p) { return assign(p); }
+
+private:
+       template<typename U>
+       RefPtr &assign(const RefPtr<U> &p)
        {
                decref();
-               data=p.data;
-               count=p.count;
+               data = p.data;
+               count = p.count;
                incref();
                return *this;
        }
 
-       T *get() const        { return data; }
-       T &operator*() const  { return *data; }
+public:
+       /** Makes the RefPtr release its reference of the data without deleting it.
+       Note that if there are other RefPtrs left with the same data, it might
+       still get deleted automatically. */
+       T *release()
+       {
+               T *d = data;
+               data = 0;
+               decref();
+               count = 0;
+               return d;
+       }
+
+       /** Marks the data to not be deleted.  This affects all RefPtrs with the
+       same data. */
+       void keep()
+       {
+               if(count)
+                       *count |= KEEP;
+       }
+
+       T *get() const { return data; }
+       T &operator*() const { return *data; }
        T *operator->() const { return data; }
        operator bool() const { return data!=0; }
 
        template<typename U>
-       static RefPtr<T> cast_dynamic(const RefPtr<U> &p)  { return RefPtr<T>(dynamic_cast<T *>(p.get()), p.count); }
-       template<typename U> friend class RefPtr;
-private:
-       T        *data;
-       unsigned *count;
+       static RefPtr<T> cast_dynamic(const RefPtr<U> &p)
+       { return RefPtr<T>(dynamic_cast<T *>(p.data), p.count); }
 
-       RefPtr(T *d, unsigned *c): data(d), count(c) { incref(); }
-
-       void  incref()
+private:
+       void incref()
        {
                if(!count) return;
                ++*count;
        }
 
-       void  decref()
+       void decref()
        {
                if(!count) return;
                --*count;
@@ -55,8 +107,14 @@ private:
                {
                        delete data;
                        delete count;
-                       data=0;
-                       count=0;
+                       data = 0;
+                       count = 0;
+               }
+               else if(*count==KEEP)
+               {
+                       delete count;
+                       data = 0;
+                       count = 0;
                }
        }
 };