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| <h1>Boost Exception</h1> |
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| <!-- Copyright (c) 2006-2009 Emil Dotchevski and Reverge Studios, Inc. --> |
| <!-- Distributed under the Boost Software License, Version 1.0. (See accompanying --> |
| <!-- file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) --> |
| <div class="RenoIncludeDIV"><div class="RenoAutoDIV"><h3>enable_current_exception</h3> |
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| <div class="RenoIncludeDIV"><p><span class="RenoEscape">#<!--<wiki>`#</wiki>--></span>include <<span class="RenoLink"><a href="boost_exception_enable_current_exception_hpp.html">boost/exception/enable_current_exception.hpp</a></span>></p> |
| <pre>namespace |
| boost |
| { |
| <span class="RenoIncludeSPAN"> template <class T> |
| ---unspecified--- <span class="RenoLink">enable_current_exception</span>( T const & e );</span> |
| }</pre> |
| </div><h4>Requirements:</h4> |
| <div><ul><li> T must be a class with an accessible no-throw copy constructor.</li> |
| <li> If T has any virtual base types, those types must have an accessible default constructor.</li> |
| </ul></div> |
| <h4>Returns:</h4> |
| <p>An object of <i>unspecified</i> type which derives publicly from T. That is, the returned object can be intercepted by a catch(T &).</p> |
| <h4>Description:</h4> |
| <p>This function is designed to be used directly in a throw-expression to enable the <span class="RenoLink"><a href="exception_ptr.html">exception_ptr</a></span> support in Boost Exception. For example:</p> |
| <pre>class |
| my_exception: |
| public std::exception |
| { |
| }; |
| |
| .... |
| throw boost::<span class="RenoLink">enable_current_exception</span>(my_exception());</pre> |
| <p>Unless <span class="RenoLink">enable_current_exception</span> is called at the time an exception object is used in a throw-expression, an attempt to copy it using <span class="RenoLink"><a href="current_exception.html">current_exception</a></span> may return an <span class="RenoLink"><a href="exception_ptr.html">exception_ptr</a></span> which refers to an instance of <span class="RenoLink"><a href="unknown_exception.html">unknown_exception</a></span>. See <span class="RenoLink"><a href="current_exception.html">current_exception</a></span> for details.</p> |
| <h4>Note:</h4> |
| <p>Instead of using the throw keyword directly, it is preferable to call boost::<span class="RenoLink"><a href="throw_exception.html">throw_exception</a></span>. This is guaranteed to throw an exception that derives from boost::<span class="RenoLink"><a href="exception.html">exception</a></span> and supports the <span class="RenoLink"><a href="exception_ptr.html">exception_ptr</a></span> functionality.</p> |
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| See also: <span class="RenoPageList"><a href="boost-exception.html">Boost Exception</a> | <a href="boost_exception_enable_current_exception_hpp.html">boost/exception/enable_current_exception.hpp</a> | <a href="configuration_macros.html">Configuration Macros</a> | <a href="copy_exception.html">copy_exception</a> | <a href="current_exception.html">current_exception</a> | <a href="frequently_asked_questions.html">Frequently Asked Questions</a> | <a href="tutorial_exception_ptr.html">Transporting of Exceptions Between Threads</a> | <a href="throw_exception.html">throw_exception</a></span> |
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| <!-- Copyright (c) 2006-2009 Emil Dotchevski and Reverge Studios, Inc. --> |
| <!-- Distributed under the Boost Software License, Version 1.0. (See accompanying --> |
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| <small>Copyright (c) 2006-2009 by Emil Dotchevski and Reverge Studios, Inc.<br/> |
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