1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Success or Exception</title> 5<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../index.html" title="Chapter 1. Fiber"> 8<link rel="up" href="../callbacks.html" title="Integrating Fibers with Asynchronous Callbacks"> 9<link rel="prev" href="return_errorcode.html" title="Return Errorcode"> 10<link rel="next" href="return_errorcode_or_data.html" title="Return Errorcode or Data"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="return_errorcode.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../callbacks.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="return_errorcode_or_data.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h3 class="title"> 27<a name="fiber.callbacks.success_or_exception"></a><a class="link" href="success_or_exception.html" title="Success or Exception">Success or Exception</a> 28</h3></div></div></div> 29<p> 30 A wrapper more aligned with modern C++ practice would use an exception, rather 31 than an <code class="computeroutput"><span class="identifier">errorcode</span></code>, to communicate 32 failure to its caller. This is straightforward to code in terms of <code class="computeroutput"><span class="identifier">write_ec</span><span class="special">()</span></code>: 33 </p> 34<p> 35</p> 36<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">write</span><span class="special">(</span> <span class="identifier">AsyncAPI</span> <span class="special">&</span> <span class="identifier">api</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">data</span><span class="special">)</span> <span class="special">{</span> 37 <span class="identifier">AsyncAPI</span><span class="special">::</span><span class="identifier">errorcode</span> <span class="identifier">ec</span> <span class="special">=</span> <span class="identifier">write_ec</span><span class="special">(</span> <span class="identifier">api</span><span class="special">,</span> <span class="identifier">data</span><span class="special">);</span> 38 <span class="keyword">if</span> <span class="special">(</span> <span class="identifier">ec</span><span class="special">)</span> <span class="special">{</span> 39 <span class="keyword">throw</span> <span class="identifier">make_exception</span><span class="special">(</span><span class="string">"write"</span><span class="special">,</span> <span class="identifier">ec</span><span class="special">);</span> 40 <span class="special">}</span> 41<span class="special">}</span> 42</pre> 43<p> 44 </p> 45<p> 46 The point is that since each fiber has its own stack, you need not repeat 47 messy boilerplate: normal encapsulation works. 48 </p> 49</div> 50<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 51<td align="left"></td> 52<td align="right"><div class="copyright-footer">Copyright © 2013 Oliver Kowalke<p> 53 Distributed under the Boost Software License, Version 1.0. (See accompanying 54 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>) 55 </p> 56</div></td> 57</tr></table> 58<hr> 59<div class="spirit-nav"> 60<a accesskey="p" href="return_errorcode.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../callbacks.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="return_errorcode_or_data.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 61</div> 62</body> 63</html> 64
