CFUtils.h   [plain text]

//===-- CFUtils.h -----------------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  Created by Greg Clayton on 3/5/07.
//
//===----------------------------------------------------------------------===//

#ifndef __CFUtils_h__
#define __CFUtils_h__

#include <CoreFoundation/CoreFoundation.h>

#ifdef __cplusplus

//----------------------------------------------------------------------
// Templatized CF helper class that can own any CF pointer and will
// call CFRelease() on any valid pointer it owns unless that pointer is
// explicitly released using the release() member function.
//----------------------------------------------------------------------
template <class T>
class CFReleaser
{
public:
            // Type names for the avlue
            typedef T element_type;

            // Constructors and destructors
            CFReleaser(T ptr = NULL) : _ptr(ptr) { }
            CFReleaser(const CFReleaser& copy) : _ptr(copy.get())
            {
                if (get())
                    ::CFRetain(get());
            }
            virtual ~CFReleaser() { reset(); }

            // Assignments
            CFReleaser& operator= (const CFReleaser<T>& copy)
            {
                if (copy != *this)
                {
                    // Replace our owned pointer with the new one
                    reset(copy.get());
                    // Retain the current pointer that we own
                    if (get())
                        ::CFRetain(get());
                }
            }
            // Get the address of the contained type
            T *     ptr_address()   { return &_ptr; }

            // Access the pointer itself
    const   T       get() const     { return _ptr;  }
            T       get()           { return _ptr;  }

            // Set a new value for the pointer and CFRelease our old
            // value if we had a valid one.
            void    reset(T ptr = NULL)
                    {
                        if (ptr != _ptr)
                        {
                            if (_ptr != NULL)
                                ::CFRelease(_ptr);
                            _ptr = ptr;
                        }
                    }

            // Release ownership without calling CFRelease
            T    release() { T tmp = _ptr; _ptr = NULL; return tmp; }
private:
    element_type _ptr;
};

#endif    // #ifdef __cplusplus
#endif    // #ifndef __CFUtils_h__