1<!DOCTYPE html PUBLIC '-//W3C//DTD XHTML 1.0 Strict//EN' 2'http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd'> 3<html xmlns='http://www.w3.org/1999/xhtml' xml:lang='en' lang='en'> 4<head> 5 <meta http-equiv='Content-Type' content='text/html; charset=utf-8'/> 6 <title>diagnostic_information</title> 7 <link href='reno.css' type='text/css' rel='stylesheet'/> 8</head> 9<body> 10<div class="body-0"> 11<div class="body-1"> 12<div class="body-2"> 13<div> 14<div id="boost_logo"> 15<a href="http://www.boost.org"><img style="border:0" src="../../../boost.png" alt="Boost" width="277" height="86"/></a> 16</div> 17<h1>Boost Exception</h1> 18</div> 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> 23</div> 24<div class="RenoIncludeDIV"><p><span class="RenoEscape">#<!--<wiki>`#</wiki>--></span>include <<span class="RenoLink"><a href="boost_exception_diagnostic_information_hpp.html">boost/exception/diagnostic_information.hpp</a></span>><span class="RenoBR"> </span><br/><span class="RenoEscape">#<!--<wiki>`#</wiki>--></span>include <<span class="RenoLink"><a href="boost_exception_ptr_hpp.html">boost/exception_ptr.hpp</a></span>><span class="RenoBR"> </span><br/></p> 25<pre>namespace 26boost 27 { 28<span class="RenoIncludeSPAN"> template <class E> 29 std::string <span class="RenoLink">diagnostic_information</span>( E const & 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 & 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<<</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><Tag,T>, 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><Tag,T> 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 << 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 } 54else return <unspecified-string-value>;</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<struct _iobuf> __cdecl my_fopen(const char *,const char *) 58Dynamic exception type: class boost::exception_detail::clone_impl<struct fopen_error> 59std::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> 65See also: <span class="RenoPageList"><a href="BOOST_THROW_EXCEPTION.html">BOOST_THROW_EXCEPTION</a> | <a href="boost-exception.html">Boost Exception</a> | <a href="boost_exception_diagnostic_information_hpp.html">boost/exception/diagnostic_information.hpp</a> | <a href="configuration_macros.html">Configuration Macros</a> | <a href="current_exception_diagnostic_information.html">current_exception_diagnostic_information</a> | <a href="tutorial_diagnostic_information.html">Diagnostic Information</a> | <a href="diagnostic_information_what.html">diagnostic_information_what</a> | <a href="frequently_asked_questions.html">Frequently Asked Questions</a> | <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) --> 70<div id="footer"> 71<p> 72<a class="logo" href="http://jigsaw.w3.org/css-validator/check/referer"><img class="logo_pic" src="valid-css.png" alt="Valid CSS" height="31" width="88"/></a> 73<a class="logo" href="http://validator.w3.org/check?uri=referer"><img class="logo_pic" src="valid-xhtml.png" alt="Valid XHTML 1.0" height="31" width="88"/></a> 74<small>Copyright (c) 2006-2009 by Emil Dotchevski and Reverge Studios, Inc.<br/> 75Distributed under the <a href="http://www.boost.org/LICENSE_1_0.txt">Boost Software License, Version 1.0</a>.</small> 76</p> 77</div> 78</div> 79</div> 80</div> 81</body> 82</html> 83
