1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Exception Translation</title> 5<link rel="stylesheet" href="../../boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../index.html" title="Boost.Python Tutorial"> 8<link rel="up" href="../index.html" title="Boost.Python Tutorial"> 9<link rel="prev" href="iterators.html" title="Iterators"> 10<link rel="next" href="techniques.html" title="General Techniques"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr><td valign="top"><img alt="" width="" height="" src="../../images/boost.png"></td></tr></table> 14<hr> 15<div class="spirit-nav"> 16<a accesskey="p" href="iterators.html"><img src="../../images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../images/home.png" alt="Home"></a><a accesskey="n" href="techniques.html"><img src="../../images/next.png" alt="Next"></a> 17</div> 18<div class="section"> 19<div class="titlepage"><div><div><h2 class="title" style="clear: both"> 20<a name="tutorial.exception"></a><a class="link" href="exception.html" title="Exception Translation">Exception Translation</a> 21</h2></div></div></div> 22<p> 23 All C++ exceptions must be caught at the boundary with Python code. This boundary 24 is the point where C++ meets Python. Boost.Python provides a default exception 25 handler that translates selected standard exceptions, then gives up: 26 </p> 27<pre class="programlisting"><span class="keyword">raise</span> <span class="identifier">RuntimeError</span><span class="special">,</span> <span class="string">'unidentifiable C++ Exception'</span> 28</pre> 29<p> 30 Users may provide custom translation. Here's an example: 31 </p> 32<pre class="programlisting"><span class="identifier">struct</span> <span class="identifier">PodBayDoorException</span><span class="special">;</span> 33<span class="identifier">void</span> <span class="identifier">translator</span><span class="special">(</span><span class="identifier">PodBayDoorException</span> <span class="identifier">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">)</span> <span class="special">{</span> 34 <span class="identifier">PyErr_SetString</span><span class="special">(</span><span class="identifier">PyExc_UserWarning</span><span class="special">,</span> <span class="string">"I'm sorry Dave..."</span><span class="special">);</span> 35<span class="special">}</span> 36<span class="identifier">BOOST_PYTHON_MODULE</span><span class="special">(</span><span class="identifier">kubrick</span><span class="special">)</span> <span class="special">{</span> 37 <span class="identifier">register_exception_translator</span><span class="special"><</span> 38 <span class="identifier">PodBayDoorException</span><span class="special">>(</span><span class="identifier">translator</span><span class="special">);</span> 39 <span class="special">...</span> 40</pre> 41</div> 42<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 43<td align="left"></td> 44<td align="right"><div class="copyright-footer">Copyright © 2002-2005 Joel 45 de Guzman, David Abrahams<p> 46 Distributed under the Boost Software License, Version 1.0. (See accompanying 47 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a> 48 </p> 49</div></td> 50</tr></table> 51<hr> 52<div class="spirit-nav"> 53<a accesskey="p" href="iterators.html"><img src="../../images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../images/home.png" alt="Home"></a><a accesskey="n" href="techniques.html"><img src="../../images/next.png" alt="Next"></a> 54</div> 55</body> 56</html> 57
