src/ptr.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
   2 /*
   3  * Contact:
   4  *   Moonlight List (moonlight-list@lists.ximian.com)
   5  *
   6  * Copyright 2007 Novell, Inc. (http://www.novell.com)
   7  *
   8  * See the LICENSE file included with the distribution for details.
   9  *
  10  */
  11
  12 #ifndef __MONO_PTR_H__
  13 #define __MONO_PTR_H__
  14 // debug
  15 #define ds(x)
  16
  17 #include "debug.h"
  18
  19 // to prevent unwanted assignments
  20 class PtrBase {
  21 private:
  22         void operator==(const PtrBase &b) const;
  23         void operator!=(const PtrBase &b) const;
  24         operator Value();
  25 };
  26
  27 /*************************************************************
  28  DOPtr takes ownership of a refcounted object, so it won't
  29  touch the initial refcount, it will only unref when destroyed
  30 **************************************************************/
  31 template<class T>
  32 class DOPtr : private PtrBase {
  33 public:
  34         DOPtr(T* ptr = 0) : value(ptr), initted(false) {
  35                 init();
  36         }
  37
  38         ~DOPtr() {
  39                 ds (printf("~DOPtr %p %p %d\n", this, value, initted));
  40                 if (value && initted)
  41                         value->unref();
  42         }
  43         operator bool() const { return(value != 0); }
  44
  45         DOPtr* operator=(T* ptr) {
  46                 if (value == ptr)
  47                         return this;
  48                 T *old = value;
  49                 value = ptr;
  50                 if (old && initted) old->unref();
  51                 initted = false;
  52                 init ();
  53                 return this;
  54         }
  55         T* get() const { return value; }
  56         T* operator->() const { return value; }
  57         T& operator*() const { return *value; }
  58
  59         operator T*() { return value; }
  60
  61         template <class U>
  62         operator U*() { return static_cast<U*> (value); }
  63
  64 private:
  65         T *value;
  66         bool initted;
  67
  68         void init() {
  69                 ds (printf("init %p %p\n", this, value));
  70                 if (!value)
  71                         return;
  72                 initted = true;
  73         }
  74 };
  75
  76 #endif