1 /*

     2 * Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:

    15 *

    16 */

    17 

    18 #ifndef JCFAUTOPTR_H

    19 #define JCFAUTOPTR_H

    20 

    21 #include <e32base.h>

    22 

    23 /**

    24  * Functionality of this auto ptr class is same as stl's auto_ptr class

    25  * except this works with cleanup stack.

    26  * Implementation of the example operation with "traditional" way:

    27  * void bar()

    28  *   {

    29  *   CFoo* myFoo = CFoo::NewL();

    30  *   CleanupStack::PushL(myFoo);

    31  *   myFoo->DoSomeThingL();

    32  *   CleanupStack::PopAndDestroy(1); //myFoo

    33  *   }

    34  * Implementation of the same function with auto pointer class:

    35  * void bar()

    36  *   {

    37  *   jcfcommon::auto_ptr<CFoo> myFoo(CFoo::NewL());

    38  *   myFoo->DoSomeThingL();

    39  *   }

    40  *

    41  */

    42 namespace jcfcommon

    43 {

    44 

    45 template<class X> class auto_ptr

    46 {

    47 public:

    48     typedef X element_type;

    49 

    50     auto_ptr(X* aPtr = 0): iPtr(aPtr),iCloseCalledFlag(EFalse)

    51     {

    52         CleanupStack::PushL(TCleanupItem(Close, (void*)this));

    53     }

    54 

    55     /**

    56      * Copy constructor was commented out because current

    57      * implementation doesn't support situation where auto_ptr

    58      * is returned as return value of the function. Problem is that

    59      * orig. auto_ptr is deleted when getBar() operation has been

    60      * executed and this deleted local reference has been stored to the

    61      * cleanup stack.

    62      * E.g:

    63      * void foo()

    64      *   {

    65      *   auto_ptr<bar> barObj = getBar();

    66      *       .

    67      *       .

    68      *       .

    69      *   User::Leave(KErrNotFound);

    70      *   }

    71      */

    72     /*auto_ptr(auto_ptr& aPtr): iPtr(aPtr.release())

    73     {

    74       CleanupStack::PushL(TCleanupItem(Close, (void*)this));

    75     }*/

    76 

    77     auto_ptr<X>& operator=(auto_ptr<X>& aRhs)

    78     {

    79         if (&aRhs != this)

    80         {

    81             delete iPtr;

    82             iPtr = aRhs.release();

    83         }

    84         return (*this);

    85     }

    86 

    87     ~auto_ptr()

    88     {

    89         if (!iCloseCalledFlag)

    90         {

    91             CleanupStack::Pop();

    92             delete iPtr;

    93         }

    94     }

    95 

    96     X& operator *() const

    97     {

    98         return *iPtr;

    99     }

   100     X* operator ->() const

   101     {

   102         return iPtr;

   103     }

   104 

   105     X* get() const

   106     {

   107         return iPtr;

   108     }

   109 

   110     X* release()

   111     {

   112         X* result = iPtr;

   113         iPtr = 0;

   114         return result;

   115     }

   116 

   117     void reset(X* aPtr = 0)

   118     {

   119         if (aPtr != iPtr)

   120         {

   121             delete iPtr;

   122             iPtr = aPtr;

   123         }

   124     }

   125 

   126 private:

   127     static void Close(void* aPtr)

   128     {

   129         auto_ptr<X>* self = (auto_ptr<X>*)aPtr;

   130         delete self->iPtr;

   131         self->iPtr = 0;

   132         self->iCloseCalledFlag = ETrue;

   133     }

   134 

   135     //Not implemented.

   136     auto_ptr(auto_ptr& aPtr);

   137 

   138 private:

   139     X* iPtr;

   140     TBool iCloseCalledFlag;

   141 };

   142 

   143 }//end jcfcommon

   144 

   145 #endif // JCFAUTOPTR_H

   146 

   147