CFUtils.h revision 24943d2ee8bfaa7cf5893e4709143924157a5c1e 
1//===-- CFUtils.h -----------------------------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  Created by Greg Clayton on 3/5/07.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef __CFUtils_h__
15#define __CFUtils_h__
16
17#include <CoreFoundation/CoreFoundation.h>
18
19#ifdef __cplusplus
20
21//----------------------------------------------------------------------
22// Templatized CF helper class that can own any CF pointer and will
23// call CFRelease() on any valid pointer it owns unless that pointer is
24// explicitly released using the release() member function.
25//----------------------------------------------------------------------
26template <class T>
27class CFReleaser
28{
29public:
30            // Type names for the avlue
31            typedef T element_type;
32
33            // Constructors and destructors
34            CFReleaser(T ptr = NULL) : _ptr(ptr) { }
35            CFReleaser(const CFReleaser& copy) : _ptr(copy.get())
36            {
37                if (get())
38                    ::CFRetain(get());
39            }
40            virtual ~CFReleaser() { reset(); }
41
42            // Assignments
43            CFReleaser& operator= (const CFReleaser<T>& copy)
44            {
45                if (copy != *this)
46                {
47                    // Replace our owned pointer with the new one
48                    reset(copy.get());
49                    // Retain the current pointer that we own
50                    if (get())
51                        ::CFRetain(get());
52                }
53            }
54            // Get the address of the contained type
55            T *     ptr_address()   { return &_ptr; }
56
57            // Access the pointer itself
58    const   T       get() const     { return _ptr;  }
59            T       get()           { return _ptr;  }
60
61            // Set a new value for the pointer and CFRelease our old
62            // value if we had a valid one.
63            void    reset(T ptr = NULL)
64                    {
65                        if (ptr != _ptr)
66                        {
67                            if (_ptr != NULL)
68                                ::CFRelease(_ptr);
69                            _ptr = ptr;
70                        }
71                    }
72
73            // Release ownership without calling CFRelease
74            T    release() { T tmp = _ptr; _ptr = NULL; return tmp; }
75private:
76    element_type _ptr;
77};
78
79#endif    // #ifdef __cplusplus
80#endif    // #ifndef __CFUtils_h__
81
82