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<!DOCTYPE concept

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<concept id="GUID-1D9376CD-3160-5CD8-A138-B94C5F7A50F8" xml:lang="en"><title>Using

MUTABLE_CAST macro</title><shortdesc>This topic explains how to cast away the constant of the counter

variable.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>In the example code below, the class has a simple const getter function <codeph>Var()</codeph>.

It uses <codeph>MUTABLE_CAST</codeph> to cast away the <codeph>const</codeph> -ness

of the counter variable <codeph>iGetCounter</codeph>, which allows that variable

to be changed.</p>

<codeblock id="GUID-8EA00511-AA50-5401-B13D-D21C4611B22F" xml:space="preserve">class TMutableDemo 

 {

public:

 TMutableDemo(TUint a=0):iVar(a),iGetCounter(0) {};

 TUint Var() const;

private:

 TUint iVar;

 __MUTABLE TUint iGetCounter;

 };

TUint TMutableDemo::Var() const 

 {

 MUTABLE_CAST(TMutableDemo*,this)->iGetCounter++;

 return iVar; 

 }</codeblock>

</conbody></concept>