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

   1 <html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Chapter 5.  Diagnostics</title><meta name="generator" content="DocBook XSL-NS Stylesheets V1.76.1"><meta name="keywords" content="
   2       ISO C++
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   6       ISO C++
   7     ,
   8       runtime
   9     ,
  10       library
  11     "><link rel="home" href="../index.html" title="The GNU C++ Library"><link rel="up" href="bk01pt02.html" title="Part II.  Standard Contents"><link rel="prev" href="termination.html" title="Termination"><link rel="next" href="bk01pt02ch05s02.html" title="Concept Checking"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 5.
  12   Diagnostics
  13
  14 </th></tr><tr><td width="20%" align="left"><a accesskey="p" href="termination.html">Prev</a> </td><th width="60%" align="center">Part II.
  15     Standard Contents
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  17   Diagnostics
  18   <a class="indexterm" name="id608748"></a>
  19 </h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><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="bk01pt02ch05s02.html">Concept Checking</a></span></dt></dl></div><div class="section" title="Exceptions"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="std.diagnostics.exceptions"></a>Exceptions</h2></div></div></div><div class="section" title="API Reference"><div class="titlepage"><div><div><h3 class="title"><a name="std.diagnostics.exceptions.api"></a>API Reference</h3></div></div></div><p>
  20       All exception objects are defined in one of the standard header
  21       files: <code class="filename">exception</code>,
  22       <code class="filename">stdexcept</code>, <code class="filename">new</code>, and
  23       <code class="filename">typeinfo</code>.
  24     </p><p>
  25       The base exception object is <code class="classname">exception</code>,
  26       located in <code class="filename">exception</code>. This object has no
  27       <code class="classname">string</code> member.
  28     </p><p>
  29       Derived from this are several classes that may have a
  30       <code class="classname">string</code> member: a full hierarchy can be
  31       found in the source documentation.
  32     </p><p>
  33       Full API details.
  34     </p></div><div class="section" title="Adding Data to exception"><div class="titlepage"><div><div><h3 class="title"><a name="std.diagnostics.exceptions.data"></a>Adding Data to <code class="classname">exception</code></h3></div></div></div><p>
  35       The standard exception classes carry with them a single string as
  36       data (usually describing what went wrong or where the 'throw' took
  37     place).  It's good to remember that you can add your own data to
  38     these exceptions when extending the hierarchy:
  39    </p><pre class="programlisting">
  40    struct My_Exception : public std::runtime_error
  41    {
  42      public:
  43        My_Exception (const string&amp; whatarg)
  44            : std::runtime_error(whatarg), e(errno), id(GetDataBaseID()) { }
  45        int  errno_at_time_of_throw() const { return e; }
  46        DBID id_of_thing_that_threw() const { return id; }
  47      protected:
  48        int    e;
  49        DBID   id;     // some user-defined type
  50    };
  51    </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="bk01pt02.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="bk01pt02ch05s02.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"> Concept Checking</td></tr></table></div></body></html>