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 //----------------------------------------------------------------------
26 template <class T> class CFReleaser {
27 public:
28   // Type names for the avlue
29   typedef T element_type;
30 
31   // Constructors and destructors
32   CFReleaser(T ptr = NULL) : _ptr(ptr) {}
33   CFReleaser(const CFReleaser &copy) : _ptr(copy.get()) {
34     if (get())
35       ::CFRetain(get());
36   }
37   virtual ~CFReleaser() { reset(); }
38 
39   // Assignments
40   CFReleaser &operator=(const CFReleaser<T> &copy) {
41     if (copy != *this) {
42       // Replace our owned pointer with the new one
43       reset(copy.get());
44       // Retain the current pointer that we own
45       if (get())
46         ::CFRetain(get());
47     }
48   }
49   // Get the address of the contained type
50   T *ptr_address() { return &_ptr; }
51 
52   // Access the pointer itself
53   const T get() const { return _ptr; }
54   T get() { return _ptr; }
55 
56   // Set a new value for the pointer and CFRelease our old
57   // value if we had a valid one.
58   void reset(T ptr = NULL) {
59     if (ptr != _ptr) {
60       if (_ptr != NULL)
61         ::CFRelease(_ptr);
62       _ptr = ptr;
63     }
64   }
65 
66   // Release ownership without calling CFRelease
67   T release() {
68     T tmp = _ptr;
69     _ptr = NULL;
70     return tmp;
71   }
72 
73 private:
74   element_type _ptr;
75 };
76 
77 #endif // #ifdef __cplusplus
78 #endif // #ifndef __CFUtils_h__
79