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  27 <a name="core.uncaught_exceptions"></a><a class="link" href="uncaught_exceptions.html" title="uncaught_exceptions">uncaught_exceptions</a>
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  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       &lt;boost/core/uncaught_exceptions.hpp&gt;</a></span></dt></dl></div>
  31 <div class="simplesect">
  32 <div class="titlepage"><div><div><h3 class="title">
  33 <a name="idm46687073001664"></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 &lt;boost/core/uncaught_exceptions.hpp&gt;">Header
  41       &lt;boost/core/uncaught_exceptions.hpp&gt;</a>
  42 </h3></div></div></div>
  43 <p>
  44         The header <code class="computeroutput"><span class="special">&lt;</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">&gt;</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>
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  84 <td align="left"></td>
  85 <td align="right"><div class="copyright-footer">Copyright &#169; 2014 Peter Dimov<br>Copyright &#169; 2014 Glen Fernandes<br>Copyright &#169; 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>
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