summaryrefslogtreecommitdiff
path: root/doc/html/boost_typeindex.html
blob: 252d2f263b12efcda4310e290c43e64ede8cfc18 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>Chapter&#160;41.&#160;Boost.TypeIndex 4.1</title>
<link rel="stylesheet" href="../../doc/src/boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="index.html" title="The Boost C++ Libraries BoostBook Documentation Subset">
<link rel="up" href="libraries.html" title="Part&#160;I.&#160;The Boost C++ Libraries (BoostBook Subset)">
<link rel="prev" href="boost_typeerasure/related.html" title="Related Work">
<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="../../boost.png"></td>
<td align="center"><a href="../../index.html">Home</a></td>
<td align="center"><a href="../../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="../../more/index.htm">More</a></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="boost_typeerasure/related.html"><img src="../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="libraries.html"><img src="../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="index.html"><img src="../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="boost_typeindex/getting_started.html"><img src="../../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;41.&#160;Boost.TypeIndex 4.1</h2></div>
<div><p class="copyright">Copyright &#169; 2012-2016 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 class="toc">
<dt><span class="section"><a href="boost_typeindex.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/config.html">Configuring and building the library</a></span></dt>
<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.using_runtime_cast_where_rtti_is">Using
      runtime_cast where RTTI is unavailable or undesirable </a></span></dt>
<dt><span class="section"><a href="boost_typeindex/examples.html#boost_typeindex.examples.exact_type_matching_storing_type">Exact
      type matching: storing type with const, volatile and reference qualifiers</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/examples.html#boost_typeindex.examples.table_of_raw_name_and_pretty_nam">Table
      of raw_name() and pretty_name() outputs with and without RTTI </a></span></dt>
<dt><span class="section"><a href="boost_typeindex/examples.html#boost_typeindex.examples.c_14_checking_namespace_at_compi">C++14:
      Checking namespace at compile time </a></span></dt>
<dt><span class="section"><a href="boost_typeindex/examples.html#boost_typeindex.examples.c_14_checking_lexigraphical_orde">C++14:
      Checking lexigraphical order of provided types </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_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.runtime_cast_hpp">Header &lt;boost/type_index/runtime_cast.hpp&gt;</a></span></dt>
<dt><span class="section"><a href="boost_typeindex_header_reference.html#header.boost.type_index.runtime_cast.boost_shared_ptr_cast_hpp">Header &lt;boost/type_index/runtime_cast/boost_shared_ptr_cast.hpp&gt;</a></span></dt>
<dt><span class="section"><a href="boost_typeindex_header_reference.html#header.boost.type_index.runtime_cast.pointer_cast_hpp">Header &lt;boost/type_index/runtime_cast/pointer_cast.hpp&gt;</a></span></dt>
<dt><span class="section"><a href="boost_typeindex_header_reference.html#header.boost.type_index.runtime_cast.reference_cast_hpp">Header &lt;boost/type_index/runtime_cast/reference_cast.hpp&gt;</a></span></dt>
<dt><span class="section"><a href="boost_typeindex_header_reference.html#header.boost.type_index.runtime_cast.register_runtime_class_hpp">Header &lt;boost/type_index/runtime_cast/register_runtime_class.hpp&gt;</a></span></dt>
<dt><span class="section"><a href="boost_typeindex_header_reference.html#header.boost.type_index.runtime_cast.std_shared_ptr_cast_hpp">Header &lt;boost/type_index/runtime_cast/std_shared_ptr_cast.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_a_custom_type_index.html">Making a custom
    type_index</a></span></dt>
<dd><dl>
<dt><span class="section"><a href="boost_typeindex/making_a_custom_type_index.html#boost_typeindex.making_a_custom_type_index.basics">Basics</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/making_a_custom_type_index.html#boost_typeindex.making_a_custom_type_index.getting_type_infos_at_runtime">Getting
      type infos at runtime</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/making_a_custom_type_index.html#boost_typeindex.making_a_custom_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/rtti_emulation_limitations.html">RTTI emulation
    limitations</a></span></dt>
<dd><dl>
<dt><span class="section"><a href="boost_typeindex/rtti_emulation_limitations.html#boost_typeindex.rtti_emulation_limitations.define_the_boost_type_index_func">Define
      the BOOST_TYPE_INDEX_FUNCTION_SIGNATURE macro</a></span></dt>
<dt><span class="section"><a href="boost_typeindex/rtti_emulation_limitations.html#boost_typeindex.rtti_emulation_limitations.fixing_pretty_name_output">Fixing
      pretty_name() output</a></span></dt>
</dl></dd>
<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="boost_typeindex.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, which is where problems start:
    </p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-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>
          erroneously do not strip const, volatile and references from type
        </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="../../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>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"><p><small>Last revised: April 11, 2018 at 14:08:01 GMT</small></p></td>
<td align="right"><div class="copyright-footer"></div></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="boost_typeerasure/related.html"><img src="../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="libraries.html"><img src="../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="index.html"><img src="../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="boost_typeindex/getting_started.html"><img src="../../doc/src/images/next.png" alt="Next"></a>
</div>
</body>
</html>