3 <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
4 <title>Why the TTI Library ?</title>
5 <link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css">
6 <meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
7 <link rel="home" href="../index.html" title="Chapter 1. The Type Traits Introspection Library">
8 <link rel="up" href="../index.html" title="Chapter 1. The Type Traits Introspection Library">
9 <link rel="prev" href="../index.html" title="Chapter 1. The Type Traits Introspection Library">
10 <link rel="next" href="tti_terminology.html" title="Terminology">
12 <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
13 <table cellpadding="2" width="100%"><tr>
14 <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td>
15 <td align="center"><a href="../../../../../index.html">Home</a></td>
16 <td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td>
17 <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
18 <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
19 <td align="center"><a href="../../../../../more/index.htm">More</a></td>
22 <div class="spirit-nav">
23 <a accesskey="p" href="../index.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.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="tti_terminology.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
26 <div class="titlepage"><div><div><h2 class="title" style="clear: both">
27 <a name="the_type_traits_introspection_library.tti_reason"></a><a class="link" href="tti_reason.html" title="Why the TTI Library ?">Why the
29 </h2></div></div></div>
31 In the Boost Type Traits library there is compile time functionality for querying
32 information about a C++ type. This information is very useful during template
33 metaprogramming and forms the basis, along with the constructs of the Boost
34 MPL library, and some other compile time libraries, for much of the template
35 metaprogramming in Boost.
38 One area which is mostly missing in the Type Traits library is the ability
39 to determine what C++ inner elements are part of a type, where the inner element
40 may be a nested type, function or data member, static function or static data
41 member, or class template.
44 There has been some of this functionality in Boost, both in already existing
45 libraries and in libraries on which others have worked but which were never
46 submitted for acceptance into Boost. An example with an existing Boost library
47 is Boost MPL, where there is functionality, in the form of macros and metafunctions,
48 to determine whether an enclosing type has a particular nested type or nested
49 class template. An example with a library which was never submitted to Boost
50 is the Concept Traits Library from which much of the functionality of this
51 library, related to type traits, was taken and expanded.
54 It may also be possible that some other Boost libraries, highly dependent on
55 advanced template metaprogramming techniques, also have internal functionality
56 to introspect a type's elements at compile time. But to the best of my knowledge
57 this sort of functionality has never been incorporated in a single Boost library.
58 This library is an attempt to do so, and to bring a recognizable set of interfaces
59 to compile-time type introspection to Boost so that other metaprogramming libraries
60 can use them for their own needs.
63 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
64 <td align="left"></td>
65 <td align="right"><div class="copyright-footer">Copyright © 2011-2013 Tropic Software
67 Distributed under the Boost Software License, Version 1.0. (See accompanying
68 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>)
73 <div class="spirit-nav">
74 <a accesskey="p" href="../index.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.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="tti_terminology.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>