<?xml version="1.0" encoding="utf-8"?>

<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->

<!-- This component and the accompanying materials are made available under the terms of the License 

"Eclipse Public License v1.0" which accompanies this distribution, 

and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->

<!-- Initial Contributors:

    Nokia Corporation - initial contribution.

Contributors: 

-->

<!DOCTYPE concept

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

<concept id="GUID-577F42BA-299E-5071-8C7A-FA0CBADCECAE" xml:lang="en"><title>The

types of array</title><shortdesc>Describes the types of array available.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<section id="GUID-A39A5291-6177-4521-AB8F-65D3F09FC333"><title>General arrays of objects</title> <p>Six general types of

array can be constructed:</p> <ul>

<li id="GUID-37305910-8E80-5F8B-9511-2354BD66BD38"><p><codeph>CArrayFixFlat&lt;Class

T&gt;</codeph>: an array of elements, all having the same length. It uses a flat

array buffer implemented by a <codeph>CBufFlat</codeph> object. The array

object itself is allocated on the heap.</p> </li>

<li id="GUID-E0E535CE-F623-57C9-86DC-BC755E00FE3F"><p><codeph>CArrayFixSeg&lt;Class

T&gt;</codeph>: an array of elements, all having the same length. It uses a segmented

array buffer implemented by a <codeph>CBufSeg</codeph> object. The array object

itself is allocated on the heap.</p> </li>

<li id="GUID-BA0B6BF0-C156-596A-B63F-9A7D262C218E"><p><codeph>CArrayVarFlat&lt;Class

T&gt;</codeph>: an array of elements having varying lengths. It uses a flat array

buffer implemented by a <codeph>CBufFlat</codeph> object. The array object

itself is allocated on the heap.</p> </li>

<li id="GUID-3E74B298-B832-5404-9002-92E7CE8D3228"><p><codeph>CArrayVarSeg&lt;Class

T&gt;</codeph>: an array of elements having varying lengths. It uses a segmented

array buffer implemented by a <codeph>CBufSeg</codeph> object. The array object

itself is allocated on the heap.</p> </li>

<li id="GUID-3A949BDB-822A-59EE-8C15-E5FB3EBC8FAE"><p><codeph>CArrayPakFlat&lt;Class

T&gt;</codeph>: an array of elements having varying lengths. It uses a flat array

buffer implemented by a <codeph>CBufFlat</codeph> object. The length value

of an element precedes the element itself within the array buffer. The array

object itself is allocated on the heap.</p> </li>

<li id="GUID-7B30A669-8BF5-5DDC-BDC2-2097C7631257"><p><codeph>RArray&lt;class

T&gt;</codeph>: a simple array of elements, all having the same length. The array

buffer is flat and is implemented by the array class as a simple piece of

linear memory. The array object itself can be constructed on the program stack.</p> </li>

</ul> </section>

<section id="GUID-3A99B95E-EF5D-4E7E-B545-7A9E1FE12C14"><title>General arrays of pointers</title> <p>There are three arrays

which can be used when the elements are <i>pointers</i> to <codeph>CBase</codeph> derived

objects. They allow type-safe access to <codeph>CBase</codeph> derived objects:</p> <ul>

<li id="GUID-F395B716-D47E-5915-834D-8B10C35BAC59"><p><codeph>CArrayPtrFlat&lt;class T&gt;</codeph>:

an array of pointers using a flat array buffer implemented by a <codeph>CBufFlat</codeph> object.

The array object itself is allocated on the heap.</p> </li>

<li id="GUID-ECE75F75-0178-5F00-8EE3-1B2BD162B764"><p><codeph>CArrayPtrSeg&lt;class T&gt;</codeph>:

an array of pointers using a segmented array buffer implemented by a <codeph>CBufSeg</codeph> object.

The array object itself is allocated on the heap.</p> </li>

<li id="GUID-F4AEDDAE-E8EA-571F-9089-BB736559FCE1"><p><codeph>RPointerArray&lt;class

T&gt;</codeph>: a simple array of pointers using a flat array buffer implemented

by the array class as a simple piece of linear memory. The array object itself

can be constructed on the program stack.</p> </li>

</ul> </section>

<section id="GUID-039B6556-C13A-4DFF-A1A7-D11A3702FE46"><title>Specialised arrays</title> <p>There are two specialised arrays

of <i>untyped</i> elements, all having the same length, which can be used

as data members of a base class in a thin template class/base class pair.

These classes are useful in situations where the type of elements forming

the array cannot be known in advance:</p> <ul>

<li id="GUID-2D1A46DD-FFA6-56FD-A0E4-9C4655B3B9C2"><p><codeph>CArrayFixFlat&lt;TAny&gt;</codeph>.

An array of untyped elements all having the same length. It uses a flat array

buffer implemented by a <codeph>CBufFlat</codeph> object.</p> </li>

<li id="GUID-CBF3264E-DE5C-5FA3-B953-CF6F14208EEB"><p><codeph>CArrayFixSeg&lt;TAny&gt;</codeph>.

An array of untyped elements all having the same length. It uses a segmented

array buffer implemented by a <codeph>CBufSeg</codeph> object.</p> </li>

</ul> <p>There are two specialised arrays of <i>untyped</i> elements, having

varying lengths, which can be used as data members of a base class in a thin

template class/base class pair. These classes are useful in situations where

the type of element forming the array is known only at the time the class

is created (i.e. at compile time):</p> <ul>

<li id="GUID-D689224C-F6F2-5A82-9A90-091663814F86"><p><codeph>CArrayVar&lt;TAny&gt;</codeph>.

An array of untyped elements with varying lengths.</p> </li>

<li id="GUID-5E2E9D37-65E8-5804-BD5B-6A37703C745B"><p><codeph>CArrayPak&lt;TAny&gt;</codeph>.

An array of packed (variable length) elements.</p> </li>

</ul> <p>There are two template specialisations of <codeph>RArray&lt;class

T&gt;</codeph>.</p> <ul>

<li id="GUID-A4F7D38C-7AE6-5E6B-A36F-1D70624C3E45"><p><codeph>RArray&lt;TInt&gt;</codeph>.

An array of signed integers</p> </li>

<li id="GUID-AB865DDB-5522-5A36-9DBB-BB0D535A9B9F"><p><codeph>RArray&lt;TUint&gt;</codeph>.

An array of signed integers.</p> </li>

</ul> </section>

</conbody></concept>