<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/> <meta http-equiv="X-UA-Compatible" content="IE=9"/> <meta name="generator" content="Doxygen 1.8.7"/> <title>libsigc++: exception_catch()</title> <link href="tabs.css" rel="stylesheet" type="text/css"/> <script type="text/javascript" src="jquery.js"></script> <script type="text/javascript" src="dynsections.js"></script> <link href="doxygen.css" rel="stylesheet" type="text/css" /> <link href="doxygen-extra.css" rel="stylesheet" type="text/css"/> </head> <body> <div id="top"><!-- do not remove this div, it is closed by doxygen! --> <div id="titlearea"> <table cellspacing="0" cellpadding="0"> <tbody> <tr style="height: 56px;"> <td style="padding-left: 0.5em;"> <div id="projectname">libsigc++  <span id="projectnumber">2.4.0</span> </div> </td> </tr> </tbody> </table> </div> <!-- end header part --> <!-- Generated by Doxygen 1.8.7 --> <div id="navrow1" class="tabs"> <ul class="tablist"> <li><a href="index.html"><span>Main Page</span></a></li> <li><a href="pages.html"><span>Related Pages</span></a></li> <li><a href="modules.html"><span>Modules</span></a></li> <li><a href="namespaces.html"><span>Namespaces</span></a></li> <li><a href="annotated.html"><span>Classes</span></a></li> </ul> </div> </div><!-- top --> <div class="header"> <div class="headertitle"> <div class="title">exception_catch()<div class="ingroups"><a class="el" href="group__adaptors.html">Adaptors</a></div></div> </div> </div><!--header--> <div class="contents"> <p><a class="el" href="namespacesigc.html#a0ae3b8a1ba26920cee4d7d9df2c39ed9">sigc::exception_catch()</a> catches an exception thrown from within the wrapped functor and directs it to a catcher functor. <a href="#details">More...</a></p> <p><a class="el" href="namespacesigc.html#a0ae3b8a1ba26920cee4d7d9df2c39ed9">sigc::exception_catch()</a> catches an exception thrown from within the wrapped functor and directs it to a catcher functor. </p> <p>This catcher can then rethrow the exception and catch it with the proper type.</p> <p>Note that the catcher is expected to return the same type as the wrapped functor so that normal flow can continue.</p> <p>Catchers can be cascaded to catch multiple types, because uncaught rethrown exceptions proceed to the next catcher adaptor.</p> <dl class="section user"><dt>Examples:</dt><dd><div class="fragment"><div class="line"><span class="keyword">struct </span>my_catch</div> <div class="line">{</div> <div class="line"> <span class="keywordtype">int</span> operator()()</div> <div class="line"> {</div> <div class="line"> <span class="keywordflow">try</span> { <span class="keywordflow">throw</span>; }</div> <div class="line"> <span class="keywordflow">catch</span> (<a class="codeRef" doxygen="/opt/gnome/share/mm-common/doctags/libstdc++.tag:http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a00900.html">std::range_error</a> e) <span class="comment">// catch what types we know</span></div> <div class="line"> { std::cerr << <span class="stringliteral">"caught "</span> << e.what() << <a class="codeRef" doxygen="/opt/gnome/share/mm-common/doctags/libstdc++.tag:http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a01616.html#a8b3758bb8f17c440c7963363f42f69f3">std::endl</a>; }</div> <div class="line"> <span class="keywordflow">return</span> 1;</div> <div class="line"> }</div> <div class="line">}</div> <div class="line"><span class="keywordtype">int</span> foo(); <span class="comment">// throws std::range_error</span></div> <div class="line"><a class="code" href="namespacesigc.html#a0ae3b8a1ba26920cee4d7d9df2c39ed9">sigc::exception_catch</a>(&foo, my_catch())();</div> </div><!-- fragment --></dd></dl> <p>The functor <a class="el" href="namespacesigc.html#a0ae3b8a1ba26920cee4d7d9df2c39ed9">sigc::exception_catch()</a> returns can be directly passed into <a class="el" href="classsigc_1_1signal7.html#adc55ac9b0f935fd87a67904022e03cb2" title="Add a slot to the list of slots. ">sigc::signal::connect()</a>.</p> <dl class="section user"><dt>Example:</dt><dd><div class="fragment"><div class="line"><a class="code" href="classsigc_1_1signal.html">sigc::signal<int></a> some_signal;</div> <div class="line">some_signal.<a class="code" href="classsigc_1_1signal7.html#adc55ac9b0f935fd87a67904022e03cb2">connect</a>(<a class="code" href="namespacesigc.html#a0ae3b8a1ba26920cee4d7d9df2c39ed9">sigc::exception_catch</a>(&foo, my_catch));</div> </div><!-- fragment --> </dd></dl> </div><!-- contents --> <!-- start footer part --> <hr class="footer"/><address class="footer"><small> Generated on Mon Sep 15 2014 15:59:58 for libsigc++ by  <a href="http://www.doxygen.org/index.html"> <img class="footer" src="doxygen.png" alt="doxygen"/> </a> 1.8.7 </small></address> </body> </html>