ceph/src/boost/libs/exception/doc/diagnostic_information.html

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  15 <a href="http://www.boost.org"><img style="border:0" src="../../../boost.png" alt="Boost" width="277" height="86"/></a>
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  17 <h1>Boost Exception</h1>
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  19 <!-- Copyright (c) 2006-2009 Emil Dotchevski and Reverge Studios, Inc. -->
  20 <!-- Distributed under the Boost Software License, Version 1.0. (See accompanying -->
  21 <!-- file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) -->
  22 <div class="RenoIncludeDIV"><div class="RenoAutoDIV"><h3>diagnostic_information</h3>
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  24 <div class="RenoIncludeDIV"><p><span class="RenoEscape">&#35;<!--<wiki>`&#35;</wiki>--></span>include &lt;<span class="RenoLink"><a href="boost_exception_diagnostic_information_hpp.html">boost/exception/diagnostic_information.hpp</a></span>&gt;<span class="RenoBR">&nbsp;</span><br/><span class="RenoEscape">&#35;<!--<wiki>`&#35;</wiki>--></span>include &lt;<span class="RenoLink"><a href="boost_exception_ptr_hpp.html">boost/exception_ptr.hpp</a></span>&gt;<span class="RenoBR">&nbsp;</span><br/></p>
  25 <pre>namespace
  26 boost
  27     {
  28 <span class="RenoIncludeSPAN">    template &lt;class E&gt;
  29     std::string <span class="RenoLink">diagnostic_information</span>( E const &amp; e, bool verbose=true );
  30
  31     std::string <span class="RenoLink">diagnostic_information</span>( <span class="RenoLink"><a href="exception_ptr.html">exception_ptr</a></span> const &amp; p, bool verbose=true );</span>
  32     }</pre>
  33 </div><h4>Returns:</h4>
  34 <p>A string value that contains varying amount of diagnostic information about the passed object:</p>
  35 <div><ul><li> If E can be statically converted to either boost::<span class="RenoLink"><a href="exception.html">exception</a></span> or to std::exception, dynamic_cast is used to access both the boost::<span class="RenoLink"><a href="exception.html">exception</a></span> and std::exception subobjects of e; otherwise, the boost::<span class="RenoLink">diagnostic_information</span> template is not available.</li>
  36 <li> The returned value contains the string representations of all <span class="RenoLink"><a href="error_info.html">error_info</a></span> objects stored in the boost::<span class="RenoLink"><a href="exception.html">exception</a></span> subobject through <span class="RenoLink"><a href="exception_operator_shl.html">operator&lt;&lt;</a></span>.</li>
  37 <li> In addition, if verbose is true, it contains other diagnostic information relevant to the exception, including the string returned by std::exception::what().</li>
  38 </ul></div>
  39 <p>The string representation of each <span class="RenoLink"><a href="error_info.html">error_info</a></span> object is deduced by an unqualified call to to_string(x), where x is of type <span class="RenoLink"><a href="error_info.html">error_info</a></span>&lt;Tag,T&gt;, for which Boost Exception defines a generic overload. It converts x.<span class="RenoLink"><a href="error_info_value.html">value</a></span>() to string, attempting to bind (at the time the <span class="RenoLink"><a href="error_info.html">error_info</a></span>&lt;Tag,T&gt; template is instantiated) the following functions in order:</p>
  40 <div><ol><li>Unqualified call to to_string(x.<span class="RenoLink"><a href="error_info_value.html">value</a></span>()) (the return value is expected to be of type std::string.)</li>
  41 <li>Unqualified call to s &lt;&lt; x.<span class="RenoLink"><a href="error_info_value.html">value</a></span>(), where s is a std::ostringstream.</li>
  42 </ol></div>
  43 <p>The first successfully bound function is used at the time <span class="RenoLink">diagnostic_information</span> is called; if both overload resolutions are unsuccessful, the system is unable to convert the <span class="RenoLink"><a href="error_info.html">error_info</a></span> object to string, and <i>an unspecified stub string value is used without issuing a compile error.</i></p>
  44 <p>The <span class="RenoLink"><a href="exception_ptr.html">exception_ptr</a></span> overload of <span class="RenoLink">diagnostic_information</span> is equivalent to:</p>
  45 <pre>if( p )
  46     try
  47         {
  48         <span class="RenoLink"><a href="rethrow_exception.html">rethrow_exception</a></span>(p);
  49         }
  50     catch(...)
  51         {
  52         return <span class="RenoLink"><a href="current_exception_diagnostic_information.html">current_exception_diagnostic_information</a></span>(verbose);
  53         }
  54 else return &lt;unspecified-string-value&gt;;</pre>
  55 <div class="RenoIncludeDIV"><h4>Example:</h4>
  56 <p>this is a possible output from the <span class="RenoLink">diagnostic_information</span> function, as used in <i>libs/exception/example/example_io.cpp:</i></p>
  57 <pre>example_io.cpp(70): Throw in function class boost::shared_ptr&lt;struct _iobuf&gt; __cdecl my_fopen(const char *,const char *)
  58 Dynamic exception type: class boost::exception_detail::clone_impl&lt;struct fopen_error&gt;
  59 std::exception::what: example_io error
  60 [struct boost::<span class="RenoLink"><a href="errinfo_api_function.html">errinfo_api_function</a></span>_ *] = fopen
  61 [struct boost::<span class="RenoLink"><a href="errinfo_errno.html">errinfo_errno</a></span>_ *] = 2, "No such file or directory"
  62 [struct boost::<span class="RenoLink"><a href="errinfo_file_name.html">errinfo_file_name</a></span>_ *] = tmp1.txt
  63 [struct boost::<span class="RenoLink"><a href="errinfo_file_open_mode.html">errinfo_file_open_mode</a></span>_ *] = rb</pre>
  64 </div></div><div class="RenoAutoDIV"><div class="RenoHR"><hr/></div>
  65 See also: <span class="RenoPageList"><a href="BOOST_THROW_EXCEPTION.html">BOOST_THROW_EXCEPTION</a>&nbsp;| <a href="boost-exception.html">Boost Exception</a>&nbsp;| <a href="boost_exception_diagnostic_information_hpp.html">boost/exception/diagnostic_information.hpp</a>&nbsp;| <a href="configuration_macros.html">Configuration Macros</a>&nbsp;| <a href="current_exception_diagnostic_information.html">current_exception_diagnostic_information</a>&nbsp;| <a href="tutorial_diagnostic_information.html">Diagnostic Information</a>&nbsp;| <a href="diagnostic_information_what.html">diagnostic_information_what</a>&nbsp;| <a href="frequently_asked_questions.html">Frequently Asked Questions</a>&nbsp;| <a href="motivation.html">Motivation</a></span>
  66 </div>
  67 <!-- Copyright (c) 2006-2009 Emil Dotchevski and Reverge Studios, Inc. -->
  68 <!-- Distributed under the Boost Software License, Version 1.0. (See accompanying -->
  69 <!-- file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) -->
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  74 <small>Copyright (c) 2006-2009 by Emil Dotchevski and Reverge Studios, Inc.<br/>
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