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    10 <!DOCTYPE concept

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

    12 <concept id="GUID-0C8389B8-91DF-58A1-A2A1-945A18CCBB10" xml:lang="en"><title>Using

    13 TLitC operators</title><shortdesc>Explains how to use <codeph>TLitC</codeph> operations.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

    14 <p>The <codeph>TLitC</codeph> class offers four operators, two of which are

    15 conversion operators.</p>

    16 <p>The conversion operators are invoked by the compiler when a <codeph>TLitC&lt;TInt&gt;</codeph> type

    17 is passed to a function which takes the following argument types:</p>

    18 <ul>

    19 <li id="GUID-BEF085A9-56B5-579F-A316-B68C108BED9B"><p>a reference by value,

    20 i.e. a <codeph>TRefByValue&lt;class              T&gt;</codeph> type</p> </li>

    21 <li id="GUID-911E904A-83F8-52B1-BAA1-0C993683BAD3"><p>a const reference to

    22 a descriptor, i.e. a <codeph>const              TDesC&amp;</codeph> type</p> </li>

    23 </ul>

    24 <p>The other two operators return:</p>

    25 <ul>

    26 <li id="GUID-B42C7636-5E8F-5BD6-98C8-1EF0E7AD388D"><p>a pointer to a constant

    27 descriptor, i.e. a <codeph>const              TDesC*</codeph> type</p> </li>

    28 <li id="GUID-141D07F5-4D60-5940-A404-2718494D6CCB"><p>a reference to a constant

    29 descriptor, i.e. a <codeph>const              TDesC&amp;</codeph> type</p> </li>

    30 </ul>

    31 <p>The following code fragments show the situations where the operators are

    32 called on a <codeph>TLitC</codeph>. The fragments are similar for both <codeph>TLitC8</codeph> and <codeph>TLitC16</codeph>.</p>

    33 <section id="GUID-AF4A4619-1C5A-4022-9700-4EB09C9001FE"><title>Reference by value conversion operator operator const __TRefDesC()</title> <p>The

    34 following code fragment shows the operator in use:</p> <codeblock id="GUID-63CE5630-61CB-5428-8F7C-EB84445FD63A" xml:space="preserve">...

    35 TBuf<256> x;

    36 ...

    37 _LIT(KTxtFormat,"There are %d cm in a metre");

    38 x.Format(KTxtFormat,100);

    39 ...

    40 </codeblock> </section>

    41 <section id="GUID-6B904805-4C60-4721-B02D-6999CA18E2F5"><title>Const descriptor reference conversion operator operator const

    42 TDesC&amp;</title> <p>The following code fragment shows the operator in use:</p> <codeblock id="GUID-8D7F387D-B675-5EC4-B88D-4389F4D5B961" xml:space="preserve">...

    43 _LIT(KSomeData,"Some data");

    44 ...

    45 TPtrC x(KSomeData);</codeblock> </section>

    46 <section id="GUID-6389D8D4-CC0E-45AA-81EC-43E86C28A7AE"><title>Address of operator operator&amp;()</title> <p>The following

    47 code fragment shows the operator in use:</p> <codeblock id="GUID-1AE87D87-53AD-5E88-864A-785D95598D02" xml:space="preserve">class CX...

    48  {

    49  void Foo(const TDesC* aDesC);

    50  };

    51 

    52 ...

    53 _LIT(KLiteral,"some text");

    54 ...

    55 CX* anx;

    56 ...

    57 anx->Foo(&KLiteral);

    58 ...</codeblock> </section>

    59 <section id="GUID-52E52945-1FFD-4B49-96C0-2D423B829033"><title>Reference operator operator()</title> <p>The following code

    60 fragment shows the operator in use:</p> <codeblock id="GUID-2A7C5828-7C2B-58F2-819E-9EAAD6071457" xml:space="preserve">...

    61 _LIT(KKeywordSelect,"select");

    62 if (KKeywordSelect().CompareF(token)<0)

    63 ...</codeblock> </section>

    64 </conbody></concept>