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    10 <!DOCTYPE concept

    11   PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

    12 <concept id="GUID-C6AB2B3A-BBFC-5B57-BECB-F46C96250502" xml:lang="en"><title>Cleanup

    13 stack support for non-CBase classes</title><shortdesc>The cleanup stack supports other types of cleanup using <codeph>CleanupStack::PushL()</codeph>.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

    14 <p>The discussion of clean up so far has assumed objects to be cleaned up

    15 are derived from <codeph>CBase</codeph>, with clean up by invoking <codeph>delete</codeph>.

    16 Other classes need explicit cleanup support to be provided by the programmer. </p>

    17 <p>The cleanup stack supports other types of cleanup. You can push: </p>

    18 <ul>

    19 <li id="GUID-7BD04FAD-E88D-5549-95DA-B62C5D07493F"><p>a pointer to any type

    20 of object. This is an object of type <codeph>TAny*</codeph>. The cleanupstack

    21 destroys this type of object with a call to <codeph>User::Free()</codeph> on

    22 the pointer pushed. This is less powerful than standard cleanup, because it

    23 frees memory and does not call the C++ destructor. </p> <p>You use the <codeph>CleanupStack::PushL(TAny*

    24 aPtr);</codeph> overload. </p> </li>

    25 <li id="GUID-2D143181-B8B5-5449-B29C-358CE7F8FB4A"><p>a pointer to an object

    26 together with a specific cleanup operation for that object. The pointer and

    27 the cleanup operation are contained in a <codeph>TCleanupItem</codeph> object. </p> <p>You

    28 use the <codeph>CleanupStack::PushL(TCleanupItem anItem)</codeph> overload. </p> <p>You

    29 must understand that the <codeph>TCleanupItem</codeph> object does not go

    30 on the cleanupstack. The pointer to the object that is contained within the <codeph>TCleanupItem</codeph> object

    31 goes on the cleanupstack. For example, if you created a TCleanupItem called

    32 myCleanupItem, you must never call <codeph>CleanupStack::Pop(myCleanupItem);</codeph> </p> </li>

    33 </ul>

    34 <p>Some utility functions are provided that make construction of a suitable <codeph>TCleanupItem</codeph> easy.

    35 See <xref href="GUID-18EF9CFA-5080-5F89-89EC-C64897612D6B.dita">How to clean up

    36 non-CBase classes</xref>.</p>

    37 </conbody></concept>