1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>uncaught_exceptions</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. Boost.Core"> 8<link rel="up" href="../index.html" title="Chapter 1. Boost.Core"> 9<link rel="prev" href="typeinfo.html" title="typeinfo"> 10<link rel="next" href="use_default.html" title="use_default"> 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="typeinfo.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="use_default.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h2 class="title" style="clear: both"> 27<a name="core.uncaught_exceptions"></a><a class="link" href="uncaught_exceptions.html" title="uncaught_exceptions">uncaught_exceptions</a> 28</h2></div></div></div> 29<div class="toc"><dl class="toc"><dt><span class="section"><a href="uncaught_exceptions.html#core.uncaught_exceptions.header_boost_core_uncaught_excep">Header 30 <boost/core/uncaught_exceptions.hpp></a></span></dt></dl></div> 31<div class="simplesect"> 32<div class="titlepage"><div><div><h3 class="title"> 33<a name="idm45312825783888"></a>Authors</h3></div></div></div> 34<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> 35 Andrey Semashev 36 </li></ul></div> 37</div> 38<div class="section"> 39<div class="titlepage"><div><div><h3 class="title"> 40<a name="core.uncaught_exceptions.header_boost_core_uncaught_excep"></a><a class="link" href="uncaught_exceptions.html#core.uncaught_exceptions.header_boost_core_uncaught_excep" title="Header <boost/core/uncaught_exceptions.hpp>">Header 41 <boost/core/uncaught_exceptions.hpp></a> 42</h3></div></div></div> 43<p> 44 The header <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">core</span><span class="special">/</span><span class="identifier">uncaught_exceptions</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 45 defines the <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">core</span><span class="special">::</span><span class="identifier">uncaught_exceptions</span></code> function, which is 46 a more portable implementation of the same named function introduced in C++17. 47 The function returns the number of the currently pending exceptions. When 48 that function returns a value greater than 0, throwing an exception from 49 a destructor can terminate the program. 50 </p> 51<p> 52 Unfortunately, the function cannot be implemented on every pre-C++17 compiler, 53 although the most commonly used compilers are supported. When the compiler 54 does not provide the necessary functionality, <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">core</span><span class="special">::</span><span class="identifier">uncaught_exceptions</span></code> 55 returns a non-zero value if at least one exception is pending (i.e. not necessarily 56 the number of pending exceptions), and <code class="computeroutput"><span class="identifier">BOOST_CORE_UNCAUGHT_EXCEPTIONS_EMULATED</span></code> 57 macro is defined. 58 </p> 59<div class="section"> 60<div class="titlepage"><div><div><h4 class="title"> 61<a name="core.uncaught_exceptions.header_boost_core_uncaught_excep.example"></a><a class="link" href="uncaught_exceptions.html#core.uncaught_exceptions.header_boost_core_uncaught_excep.example" title="Example">Example</a> 62</h4></div></div></div> 63<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">my_class</span> 64<span class="special">{</span> 65<span class="keyword">private</span><span class="special">:</span> 66 <span class="keyword">const</span> <span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">m_exception_count</span><span class="special">;</span> 67 68<span class="keyword">public</span><span class="special">:</span> 69 <span class="identifier">my_class</span><span class="special">()</span> <span class="special">:</span> <span class="identifier">m_exception_count</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">core</span><span class="special">::</span><span class="identifier">uncaught_exceptions</span><span class="special">())</span> 70 <span class="special">{</span> 71 <span class="special">}</span> 72 73 <span class="special">~</span><span class="identifier">my_class</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">false</span><span class="special">)</span> 74 <span class="special">{</span> 75 <span class="keyword">if</span> <span class="special">(</span><span class="identifier">m_exception_count</span> <span class="special">==</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">core</span><span class="special">::</span><span class="identifier">uncaught_exceptions</span><span class="special">())</span> 76 <span class="identifier">do_something_potentially_throwing</span><span class="special">();</span> 77 <span class="special">}</span> 78<span class="special">};</span> 79</pre> 80</div> 81</div> 82</div> 83<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 84<td align="left"></td> 85<td align="right"><div class="copyright-footer">Copyright © 2014 Peter Dimov<br>Copyright © 2014 Glen Fernandes<br>Copyright © 2014 Andrey Semashev<p> 86 Distributed under the <a href="http://boost.org/LICENSE_1_0.txt" target="_top">Boost 87 Software License, Version 1.0</a>. 88 </p> 89</div></td> 90</tr></table> 91<hr> 92<div class="spirit-nav"> 93<a accesskey="p" href="typeinfo.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="use_default.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 94</div> 95</body> 96</html> 97
