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<concept id="GUID-F3090A98-267F-5310-83F4-93FD5CB760D6" xml:lang="en"><title>Using

CCirBuf</title><shortdesc>This document describes how to use CCirBuf.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<section id="GUID-92DAE8AD-1D5A-40CA-AA36-C1E0A3648D77"><title>Before adding/removing objects</title> <p>The buffer itself

is not allocated until <xref href="GUID-FA17C8AD-BF8C-3FD4-98AE-43AF55A9D318.dita#GUID-FA17C8AD-BF8C-3FD4-98AE-43AF55A9D318/GUID-4658AA47-E3E6-3325-A4DF-FACADFA5BBB2"><apiname>CCirBufBase::SetLengthL()</apiname></xref> is called.

Therefore, the first steps must always be to construct the <xref href="GUID-1D73835F-4361-3216-8EFC-669364E3F5E7.dita"><apiname>CCirBuf</apiname></xref> object

and then call its <codeph>CCirBufBase::SetLengthL()</codeph> member function.</p> <p>Also

note that <codeph>SetLengthL()</codeph> can leave so it's useful to call it

under a trap harness.</p> <codeblock id="GUID-FED3E087-48D8-53EC-911D-12475D2B8905" xml:space="preserve">class Test

 {

public:

 Test(){a=b=0;}

 Test(TInt anInt){a=b=anInt;}

private

 TInt a;

 TInt b;

 };</codeblock> <codeblock id="GUID-3AAF1D67-BB67-5019-9D11-AB17E18254A3" xml:space="preserve">

CCirBuf<Test>* cbInt=new CCirBuf<Test>;

TRAPD(ret,cbInt->SetLengthL(3));            // max capacity is 3

                                            // and allocates buffer

Test one(1);

Test two(2);

...

cbInt->Add(&one);     // Can now start adding/removing objects

...

delete cbInt;</codeblock> </section>