<?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-F9FCE3FC-42E4-5E9E-9AFC-A9B02E2612A2" xml:lang="en"><title>Using
TRefByValue&lt;class T&gt; Class</title><shortdesc>This document describes how to use the TRefByValue&lt;class T&gt;
class.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
<p>Functions which take a variable number of arguments, such as <codeph>TDes8::Format()</codeph>,
always take the first parameter as a value reference.</p>
<p>For example, the function <codeph>TDes8::Format()</codeph> is prototyped
as:</p>
<codeblock id="GUID-A3704F62-5577-585E-A6D5-052194467C7D" xml:space="preserve">void Format(TRefByValue&lt;const TDesC8&gt; aFmt,...);</codeblock>
<p>The first argument is a value reference for a <codeph>const         TDesC8</codeph> type.
Just pass a parameter of this type or a parameter that can be converted to
that type. </p>
<codeblock id="GUID-D4B86B9C-43B9-53A1-9038-A9515D6A806B" xml:space="preserve">_LIT(KFormat1,"%b %c %d %o %u %x");
...
tgt.Format(KFormat1,65,65,65,65,65,65);
...</codeblock>
</conbody></concept>