Symbian3/SDK/Source/GUID-FC24C65C-0DCB-5E07-9A68-9001D34664DD.dita
author Dominic Pinkman <dominic.pinkman@nokia.com>
Tue, 20 Jul 2010 12:00:49 +0100
changeset 13 48780e181b38
parent 0 89d6a7a84779
permissions -rw-r--r--
Week 28 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 1897 and Bug 1522.
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
0
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     1
<?xml version="1.0" encoding="utf-8"?>
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     2
<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     3
<!-- This component and the accompanying materials are made available under the terms of the License 
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     4
"Eclipse Public License v1.0" which accompanies this distribution, 
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     5
and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     6
<!-- Initial Contributors:
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     7
    Nokia Corporation - initial contribution.
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     8
Contributors: 
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
     9
-->
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    10
<!DOCTYPE concept
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    11
  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    12
<concept xml:lang="en" id="GUID-FC24C65C-0DCB-5E07-9A68-9001D34664DD"><title>OR_LEAVE MACRO</title><prolog><metadata><keywords/></metadata></prolog><conbody><p>The <xref href="GUID-7EB97E3A-90F5-3536-B7AC-F6F55023E2F3.dita"><apiname>OR_LEAVE</apiname></xref> macro is a convenient macro that allows the application developer to de-emphasize auxiliary error checking code in most cases. It is a postfix macro which implements <xref href="GUID-C197C9A7-EA05-3F24-9854-542E984C612D.dita#GUID-C197C9A7-EA05-3F24-9854-542E984C612D/GUID-80E99D34-F4A1-36EA-AD64-E14ACAEC99B0"><apiname>User::LeaveIfError</apiname></xref> on an integer return type. This means that there is less focus on the error handling code and makes the code easier to read. </p> <section><title>Need for OR_Leave Macro</title> <p>Motive behind using a <xref href="GUID-7EB97E3A-90F5-3536-B7AC-F6F55023E2F3.dita"><apiname>OR_LEAVE</apiname></xref> macro is that it should not return an integer value. It is intended for use as a postfix macro at the end of a statement. If OR_LEAVE was to return an integer value, it would encourage its use in the middle of expressions negating its intended purpose which is to reduce the focus on error checking code. </p> </section> <example><title>Defining OR_Leave Macro</title> <p>The OR_LEAVE macro is defined as a postfix operator as shown below: </p> <codeblock id="GUID-DDB19E73-7D96-5D06-8EF9-AEC1248E8644" xml:space="preserve">
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    13
        #define OR_LEAVE || ELeave
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    14
        inline void operator||(TInt aStatus, TLeave /*aTag*/)
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    15
            {
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    16
            User::LeaveIfError(aStatus);
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    17
            }
89d6a7a84779 Initial contribution of Documentation_content according to Feature bug 1266 bug 1268 bug 1269 bug 1270 bug 1372 bug 1374 bug 1375 bug 1379 bug 1380 bug 1381 bug 1382 bug 1383 bug 1385
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    18
</codeblock> </example> <section><title>See Also</title> <p><xref href="GUID-B007634D-4D55-528A-8B85-6120C633AC8B.dita">EUser High Level Library Overview</xref>  </p> <p><xref href="GUID-D33EB877-CCCB-527B-8AFC-4A8385C55E78.dita">EUser High Level Library Tutorials</xref>  </p> </section> </conbody></concept>