boost_type_index/index.html

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>Chapter&#160;1.&#160;Boost.TypeIndex 3.0</title>
<link rel="stylesheet" href="http://www.boost.org/doc/libs/1_53_0/doc/src/boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
<link rel="home" href="index.html" title="Chapter&#160;1.&#160;Boost.TypeIndex 3.0">
<link rel="next" href="boost_typeindex/getting_started.html" title="Getting started">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr>
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="http://www.boost.org/doc/libs/1_53_0/boost.png"></td>
<td align="center"><a href="http://www.boost.org/doc/libs/1_53_0/index.html">Home</a></td>
<td align="center"><a href="http://www.boost.org/doc/libs/1_53_0/libs/libraries.htm">Libraries</a></td>
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
<td align="center"><a href="http://www.boost.org/doc/libs/1_53_0/more/index.htm">More</a></td>
</tr></table>
<hr>
<div class="spirit-nav"><a accesskey="n" href="boost_typeindex/getting_started.html"><img src="http://www.boost.org/doc/libs/1_53_0/doc/src/images/next.png" alt="Next"></a></div>
<div class="chapter">
<div class="titlepage"><div>
<div><h2 class="title">
<a name="boost_typeindex"></a>Chapter&#160;1.&#160;Boost.TypeIndex 3.0</h2></div>
<div><p class="copyright">Copyright &#169; 2012-2014 Antony Polukhin</p></div>
<div><div class="legalnotice">
<a name="boost_typeindex.legal"></a><p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
      </p>
</div></div>
</div></div>
<div class="toc">
<p><b>Table of Contents</b></p>
<dl>
<dt><span class="section"><a href="index.html#boost_typeindex.motivation">Motivation</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/getting_started.html">Getting started</a></span></dt>
<dd><dl>
<dt><span class="section"><a href="boost_typeindex/getting_started.html#boost_typeindex.getting_started.how_to_use">How to use</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/getting_started.html#boost_typeindex.getting_started.example_with_boost_any">Example
      with Boost.Any</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/getting_started.html#boost_typeindex.getting_started.example_with_boost_variant">Example
      with Boost.Variant</a></span></dt>
</dl></dd>
<dt><span class="section"><a href="boost_typeindex/how_it_works.html">How it works</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/examples.html">Examples</a></span></dt>
<dd><dl>
<dt><span class="section"><a href="boost_typeindex/examples.html#boost_typeindex.examples.getting_human_readable_and_mangl">Getting
      human readable and mangled type names</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/examples.html#boost_typeindex.examples.storing_information_about_a_type">Storing
      information about a type in container </a></span></dt>
<dt><span class="section"><a href="boost_typeindex/examples.html#boost_typeindex.examples.getting_through_the_inheritance_">Getting
      through the inheritance to receive a real type name </a></span></dt>
<dt><span class="section"><a href="boost_typeindex/examples.html#boost_typeindex.examples.exact_type_match_storing_type_wi">Exact
      type match: storing type with const, volatile and reference </a></span></dt>
</dl></dd>
<dt><span class="section"><a href="boost_typeindex_header_reference.html">Boost.TypeIndex Header Reference</a></span></dt>
<dd><dl>
<dt><span class="section"><a href="boost_typeindex_header_reference.html#header.boost.type_index_hpp">Header &lt;boost/type_index.hpp&gt;</a></span></dt>
<dt><span class="section"><a href="boost_typeindex_header_reference.html#header.boost.type_index.ctti_register_class_hpp">Header &lt;boost/type_index/ctti_register_class.hpp&gt;</a></span></dt>
<dt><span class="section"><a href="boost_typeindex_header_reference.html#header.boost.type_index.ctti_type_index_hpp">Header &lt;boost/type_index/ctti_type_index.hpp&gt;</a></span></dt>
<dt><span class="section"><a href="boost_typeindex_header_reference.html#header.boost.type_index.stl_register_class_hpp">Header &lt;boost/type_index/stl_register_class.hpp&gt;</a></span></dt>
<dt><span class="section"><a href="boost_typeindex_header_reference.html#header.boost.type_index.stl_type_index_hpp">Header &lt;boost/type_index/stl_type_index.hpp&gt;</a></span></dt>
<dt><span class="section"><a href="boost_typeindex_header_reference.html#header.boost.type_index.type_index_facade_hpp">Header &lt;boost/type_index/type_index_facade.hpp&gt;</a></span></dt>
</dl></dd>
<dt><span class="section"><a href="boost_typeindex/making_own_type_index.html">Making own type_index</a></span></dt>
<dd><dl>
<dt><span class="section"><a href="boost_typeindex/making_own_type_index.html#boost_typeindex.making_own_type_index.basics">Basics</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/making_own_type_index.html#boost_typeindex.making_own_type_index.getting_type_infos_at_runtime">Getting
      type infos at runtime</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/making_own_type_index.html#boost_typeindex.making_own_type_index.using_new_type_infos_all_around_">Using
      new type infos all around the code</a></span></dt>
</dl></dd>
<dt><span class="section"><a href="boost_typeindex/space_and_performance.html">Space and Performance</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/code_bloat.html">Code bloat</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/compiler_support.html">Compiler support</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/mixing_sources_with_rtti_on_and_.html">Mixing
    sources with RTTI on and RTTI off</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/acknowledgements.html">Acknowledgements</a></span></dt>
</dl>
</div>
<div class="section">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="boost_typeindex.motivation"></a><a class="link" href="index.html#boost_typeindex.motivation" title="Motivation">Motivation</a>
</h2></div></div></div>
<p>
      Sometimes getting and storing information about a type at runtime is required.
      For such cases a construction like <code class="computeroutput"><span class="special">&amp;</span><span class="keyword">typeid</span><span class="special">(</span><span class="identifier">T</span><span class="special">)</span></code> or C++11 class <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">type_index</span></code>
      is usually used. And that is the point, where problems start:
    </p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
          <code class="computeroutput"><span class="keyword">typeid</span><span class="special">(</span><span class="identifier">T</span><span class="special">)</span></code> and
          <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">type_index</span></code> require Run Time Type Info
          (RTTI)
        </li>
<li class="listitem">
          some implementations of <code class="computeroutput"><span class="keyword">typeid</span><span class="special">(</span><span class="identifier">T</span><span class="special">)</span></code>
          strip const, volatile and references from type, while others don't
        </li>
<li class="listitem">
          some compilers have bugs and do not correctly compare <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">type_info</span></code>
          objects across shared libraries
        </li>
<li class="listitem">
          only a few implementations of Standard Library currently provide <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">type_index</span></code>
        </li>
<li class="listitem">
          no easy way to store type info without stripping const, volatile and references
        </li>
<li class="listitem">
          no nice and portable way to get human readable type names
        </li>
<li class="listitem">
          no way to easily make your own type info class
        </li>
</ul></div>
<p>
      Boost.TypeIndex library was designed to work around all those issues.
    </p>
<div class="note"><table border="0" summary="Note">
<tr>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="http://www.boost.org/doc/libs/1_53_0/doc/src/images/note.png"></td>
<th align="left">Note</th>
</tr>
<tr><td align="left" valign="top"><p>
        <code class="computeroutput"><span class="identifier">T</span></code> means type here. Think
        of it as of <code class="computeroutput"><span class="identifier">T</span></code> in <code class="computeroutput"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span></code>
      </p></td></tr>
</table></div>
<div class="warning"><table border="0" summary="Warning">
<tr>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Warning]" src="http://www.boost.org/doc/libs/1_53_0/doc/src/images/warning.png"></td>
<th align="left">Warning</th>
</tr>
<tr><td align="left" valign="top"><p>
        Version 3.0 of this library is waitning for Boost mini-review.
      </p></td></tr>
</table></div>
</div>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"><p><small>Last revised: February 21, 2014 at 13:52:51 GMT</small></p></td>
<td align="right"><div class="copyright-footer"></div></td>
</tr></table>
<hr>
<div class="spirit-nav"><a accesskey="n" href="boost_typeindex/getting_started.html"><img src="http://www.boost.org/doc/libs/1_53_0/doc/src/images/next.png" alt="Next"></a></div>
</body>
</html>