docs/reference/html/group__exception__catch.html

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  21    <div id="projectname">libsigc++
  22    &#160;<span id="projectnumber">2.99.2</span>
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  43 <div class="title">exception_catch()<div class="ingroups"><a class="el" href="group__adaptors.html">Adaptors</a></div></div>  </div>
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  46
  47 <p><a class="el" href="namespacesigc.html#adc5264be500bc695232d72de44eb34e6">sigc::exception_catch()</a> catches an exception thrown from within the wrapped functor and directs it to a catcher functor.
  48 <a href="#details">More...</a></p>
  49 <p><a class="el" href="namespacesigc.html#adc5264be500bc695232d72de44eb34e6">sigc::exception_catch()</a> catches an exception thrown from within the wrapped functor and directs it to a catcher functor. </p>
  50 <p>This catcher can then rethrow the exception and catch it with the proper type.</p>
  51 <p>Note that the catcher is expected to return the same type as the wrapped functor so that normal flow can continue.</p>
  52 <p>Catchers can be cascaded to catch multiple types, because uncaught rethrown exceptions proceed to the next catcher adaptor.</p>
  53 <dl class="section user"><dt>Examples:</dt><dd><div class="fragment"><div class="line"><span class="keyword">struct </span>my_catch</div>
  54 <div class="line">{</div>
  55 <div class="line">  <span class="keywordtype">int</span> operator()()</div>
  56 <div class="line">  {</div>
  57 <div class="line">    <span class="keywordflow">try</span> { <span class="keywordflow">throw</span>; }</div>
  58 <div class="line">    <span class="keywordflow">catch</span> (<a class="codeRef" doxygen="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>
  59 <div class="line">      { std::cerr &lt;&lt; <span class="stringliteral">&quot;caught &quot;</span> &lt;&lt; e.what() &lt;&lt; <a class="codeRef" doxygen="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>
  60 <div class="line">    <span class="keywordflow">return</span> 1;</div>
  61 <div class="line">  }</div>
  62 <div class="line">}</div>
  63 <div class="line"><span class="keywordtype">int</span> foo(); <span class="comment">// throws std::range_error</span></div>
  64 <div class="line"><a class="code" href="namespacesigc.html#adc5264be500bc695232d72de44eb34e6">sigc::exception_catch</a>(&amp;foo, my_catch())();</div>
  65 </div><!-- fragment --></dd></dl>
  66 <p>The functor <a class="el" href="namespacesigc.html#adc5264be500bc695232d72de44eb34e6">sigc::exception_catch()</a> returns can be directly passed into sigc::signal::connect().</p>
  67 <dl class="section user"><dt>Example:</dt><dd><div class="fragment"><div class="line"><a class="code" href="classsigc_1_1signal.html">sigc::signal&lt;int()&gt;</a> some_signal;</div>
  68 <div class="line">some_signal.connect(<a class="code" href="namespacesigc.html#adc5264be500bc695232d72de44eb34e6">sigc::exception_catch</a>(&amp;foo, my_catch));</div>
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