libstdc++-v3/doc/html/manual/diagnostics.html

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   3   Diagnostics
   4
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   6     Standard Contents
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   8   Diagnostics
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  10 </h2></div></div></div><div class="toc"><p><strong>Table of Contents</strong></p><dl class="toc"><dt><span class="section"><a href="diagnostics.html#std.diagnostics.exceptions">Exceptions</a></span></dt><dd><dl><dt><span class="section"><a href="diagnostics.html#std.diagnostics.exceptions.api">API Reference</a></span></dt><dt><span class="section"><a href="diagnostics.html#std.diagnostics.exceptions.data">Adding Data to <code class="classname">exception</code></a></span></dt></dl></dd><dt><span class="section"><a href="errno.html">Use of errno by the library</a></span></dt><dt><span class="section"><a href="concept_checking.html">Concept Checking</a></span></dt></dl></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="std.diagnostics.exceptions"></a>Exceptions</h2></div></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="std.diagnostics.exceptions.api"></a>API Reference</h3></div></div></div><p>
  11       All exception objects are defined in one of the standard header
  12       files: <code class="filename">exception</code>,
  13       <code class="filename">stdexcept</code>, <code class="filename">new</code>, and
  14       <code class="filename">typeinfo</code>.
  15     </p><p>
  16       The base exception object is <code class="classname">exception</code>,
  17       located in <code class="filename">exception</code>. This object has no
  18       <code class="classname">string</code> member.
  19     </p><p>
  20       Derived from this are several classes that may have a
  21       <code class="classname">string</code> member: a full hierarchy can be
  22       found in the source documentation.
  23     </p><p>
  24       Full API details.
  25     </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="std.diagnostics.exceptions.data"></a>Adding Data to <code class="classname">exception</code></h3></div></div></div><p>
  26       The standard exception classes carry with them a single string as
  27       data (usually describing what went wrong or where the 'throw' took
  28     place).  It's good to remember that you can add your own data to
  29     these exceptions when extending the hierarchy:
  30    </p><pre class="programlisting">
  31    struct My_Exception : public std::runtime_error
  32    {
  33      public:
  34        My_Exception (const string&amp; whatarg)
  35            : std::runtime_error(whatarg), e(errno), id(GetDataBaseID()) { }
  36        int  errno_at_time_of_throw() const { return e; }
  37        DBID id_of_thing_that_threw() const { return id; }
  38      protected:
  39        int    e;
  40        DBID   id;     // some user-defined type
  41    };
  42    </pre></div></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="termination.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="std_contents.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="errno.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Termination </td><td width="20%" align="center"><a accesskey="h" href="../index.html">Home</a></td><td width="40%" align="right" valign="top"> Use of errno by the library</td></tr></table></div></body></html>