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1 <?xml version="1.0" encoding="utf-8"?> |
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2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. --> |
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3 <!-- This component and the accompanying materials are made available under the terms of the License |
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4 "Eclipse Public License v1.0" which accompanies this distribution, |
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5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". --> |
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6 <!-- Initial Contributors: |
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7 Nokia Corporation - initial contribution. |
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8 Contributors: |
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9 --> |
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10 <!DOCTYPE concept |
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11 PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
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12 <concept id="GUID-24D16BF8-7BF1-5FF2-BCA8-E5200A9E8431" xml:lang="en"><title>How |
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13 to form links</title><shortdesc>To be an element of a list, each element needs to contain a link |
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14 object.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody> |
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15 <p>To form a singly linked list of <codeph>CMyClass</codeph> objects, include |
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16 the link object <codeph>TSglQueLink</codeph> as a component of <codeph>CMyClass</codeph>:</p> |
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17 <codeblock id="GUID-C4ED06AA-9187-5EE6-96C5-39F41C218437" xml:space="preserve">class CMyClass : public CBase |
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18 { |
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19 ... |
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20 TSglQueLink iSlink; |
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21 ... |
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22 };</codeblock> |
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23 <fig id="GUID-C1BDFB57-AAD9-55A2-8E02-D9277BCCE122"> |
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24 <title>Two elements in a linked list</title> |
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25 <image href="GUID-C014FC75-732F-558F-8E6A-77DDAA032930_d0e218202_href.png" placement="inline"/> |
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26 </fig> |
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27 <p>Although any kind of object can be an element of a linked list, most lists |
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28 consist of elements which are all of the same type.</p> |
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29 <p>An object can participate in more than one list. For example, to allow <codeph>CMyClass</codeph> objects |
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30 to participate in two singly linked lists, include two separate <codeph>TSglQueLink</codeph> objects |
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31 as components of <codeph>CMyClass</codeph>:</p> |
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32 <codeblock id="GUID-A16512BF-ACB8-5E7E-B4B1-FD76208E0FBD" xml:space="preserve">class CMyClass : public CBase |
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33 { |
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34 ... |
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35 TSglQueLink iSlink1; |
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36 ... |
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37 TSglQueLink iSlink2; |
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38 };</codeblock> |
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39 <fig id="GUID-AA2CB21D-B848-5ADF-8B0E-7E2928C84DBE"> |
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40 <title>An example of two elements, in two lists where they are consecutive |
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41 elements in both lists</title> |
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42 <image href="GUID-773A0EDC-F17C-553B-BEC3-DA990F5064B7_d0e218228_href.png" placement="inline"/> |
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43 </fig> |
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44 <p>Elements can also be objects constructed from a variety of classes, all |
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45 ultimately derived from the same base class, where that base class includes |
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46 the link object as a component. For example, if <codeph>CBc</codeph> is a |
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47 base class for <codeph>CDc1</codeph> which, in turn, is a base class for <codeph>CDc2</codeph>, |
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48 then the elements of the list can consist of a mix of <codeph>CBc</codeph> or <codeph>CDc1</codeph> or <codeph>CDc2</codeph> objects.</p> |
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49 <codeblock id="GUID-A4624B83-5DF4-5923-A3C4-4C67E6FCF47C" xml:space="preserve">class CBc : public CBase |
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50 { |
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51 ... |
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52 TSglQueLink iSlink; |
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53 ... |
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54 };</codeblock> |
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55 <codeblock id="GUID-2139FC00-2ADF-5E70-9293-93D347DAF41A" xml:space="preserve">class CDc1 : public CBclass |
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56 { |
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57 ... |
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58 } |
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59 </codeblock> |
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60 <codeblock id="GUID-4A170483-64BF-559A-B2B1-6F31F8A7F82B" xml:space="preserve">class CDc2 : public CDc1 |
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61 { |
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62 ... |
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63 } |
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64 </codeblock> |
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65 <fig id="GUID-408F856C-86C0-5ED2-A61D-2F81B41566DD"> |
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66 <title>Example of a linked list of different element types</title> |
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67 <image href="GUID-935057C9-8FA9-5B41-A36C-03A825C51B32_d0e218266_href.png" placement="inline"/> |
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68 </fig> |
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69 <p>Note that the link object is at the same offset in each element in this |
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70 list.</p> |
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71 <p>New link elements can be inserted at the beginning or the end of the list, |
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72 but not into the middle of the list. The functionality for this is provided |
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73 by the header <codeph>TSglQue<class T></codeph>.</p> |
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74 </conbody></concept> |