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| <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Chapter 5. Diagnostics</title><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><meta name="keywords" content="ISO C++, library" /><meta name="keywords" content="ISO C++, runtime, library" /><link rel="home" href="../index.html" title="The GNU C++ Library" /><link rel="up" href="std_contents.html" title="Part II. Standard Contents" /><link rel="prev" href="termination.html" title="Termination" /><link rel="next" href="errno.html" title="Use of errno by the library" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 5. |
| Diagnostics |
| |
| </th></tr><tr><td width="20%" align="left"><a accesskey="p" href="termination.html">Prev</a> </td><th width="60%" align="center">Part II. |
| Standard Contents |
| </th><td width="20%" align="right"> <a accesskey="n" href="errno.html">Next</a></td></tr></table><hr /></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="std.diagnostics"></a>Chapter 5. |
| Diagnostics |
| <a id="id-1.3.4.3.1.1.1" class="indexterm"></a> |
| </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> |
| Most exception classes are defined in one of the standard headers |
| <code class="filename"><exception></code>, |
| <code class="filename"><stdexcept></code>, |
| <code class="filename"><new></code>, and |
| <code class="filename"><typeinfo></code>. |
| The C++ 2011 revision of the standard added more exception types |
| in the headers |
| <code class="filename"><functional></code>, |
| <code class="filename"><future></code>, |
| <code class="filename"><regex></code>, and |
| <code class="filename"><system_error></code>. |
| The C++ 2017 revision of the standard added more exception types |
| in the headers |
| <code class="filename"><any></code>, |
| <code class="filename"><filesystem></code>, |
| <code class="filename"><optional></code>, and |
| <code class="filename"><variant></code>. |
| </p><p> |
| All exceptions thrown by the library have a base class of type |
| <code class="classname">std::exception</code>, |
| defined in <code class="filename"><exception></code>. |
| This type has no <code class="classname">std::string</code> member. |
| </p><p> |
| Derived from this are several classes that may have a |
| <code class="classname">std::string</code> member. A full hierarchy can be |
| found in the source documentation. |
| </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> |
| The standard exception classes carry with them a single string as |
| data (usually describing what went wrong or where the 'throw' took |
| place). It's good to remember that you can add your own data to |
| these exceptions when extending the hierarchy: |
| </p><pre class="programlisting"> |
| struct My_Exception : public std::runtime_error |
| { |
| public: |
| My_Exception (const string& whatarg) |
| : std::runtime_error(whatarg), e(errno), id(GetDataBaseID()) { } |
| int errno_at_time_of_throw() const { return e; } |
| DBID id_of_thing_that_threw() const { return id; } |
| protected: |
| int e; |
| DBID id; // some user-defined type |
| }; |
| </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> |