<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Exception Translation</title> <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> <link rel="home" href="../index.html" title="Chapter 1. python 2.0"> <link rel="up" href="../index.html" title="Chapter 1. python 2.0"> <link rel="prev" href="iterators.html" title="Iterators"> <link rel="next" href="techniques.html" title="General Techniques"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td> <td align="center"><a href="../../../../../../../index.html">Home</a></td> <td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td> <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> <td align="center"><a href="../../../../../../../more/index.htm">More</a></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="iterators.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="techniques.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h2 class="title" style="clear: both"> <a name="python.exception"></a> Exception Translation</h2></div></div></div> <p> All C++ exceptions must be caught at the boundary with Python code. This boundary is the point where C++ meets Python. Boost.Python provides a default exception handler that translates selected standard exceptions, then gives up: </p> <pre class="programlisting"><span class="keyword">raise</span> <span class="identifier">RuntimeError</span><span class="special">,</span> <span class="string">'unidentifiable C++ Exception'</span> </pre> <p> Users may provide custom translation. Here's an example: </p> <pre class="programlisting"><span class="identifier">struct</span> <span class="identifier">PodBayDoorException</span><span class="special">;</span> <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> <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> <span class="special">}</span> <span class="identifier">BOOST_PYTHON_MODULE</span><span class="special">(</span><span class="identifier">kubrick</span><span class="special">)</span> <span class="special">{</span> <span class="identifier">register_exception_translator</span><span class="special"><</span> <span class="identifier">PodBayDoorException</span><span class="special">>(</span><span class="identifier">translator</span><span class="special">);</span> <span class="special">...</span> </pre> </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> <td align="right"><div class="copyright-footer">Copyright © 2002-2005 Joel de Guzman, David Abrahams<p> Distributed under the Boost Software License, Version 1.0. (See accompanying 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>) </p> </div></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="iterators.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="techniques.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>