libs/tti/doc/html/BOOST_TTI_MEMBER_TYPE.html

   1 <html>
   2 <head>
   3 <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
   4 <title>Macro BOOST_TTI_MEMBER_TYPE</title>
   5 <link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css">
   6 <meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
   7 <link rel="home" href="index.html" title="Chapter&#160;1.&#160;The Type Traits Introspection Library">
   8 <link rel="up" href="header/boost/tti/member_type_hpp.html" title="Header &lt;boost/tti/member_type.hpp&gt;">
   9 <link rel="prev" href="BOOST_TT_idm46187185643920.html" title="Macro BOOST_TTI_TRAIT_MEMBER_TYPE">
  10 <link rel="next" href="the_type_traits_introspection_library/tti_tests.html" title="Testing TTI">
  11 </head>
  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>
  20 </tr></table>
  21 <hr>
  22 <div class="spirit-nav">
  23 <a accesskey="p" href="BOOST_TT_idm46187185643920.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="header/boost/tti/member_type_hpp.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="the_type_traits_introspection_library/tti_tests.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a>
  24 </div>
  25 <div class="refentry">
  26 <a name="BOOST_TTI_MEMBER_TYPE"></a><div class="titlepage"></div>
  27 <div class="refnamediv">
  28 <h2><span class="refentrytitle">Macro BOOST_TTI_MEMBER_TYPE</span></h2>
  29 <p>BOOST_TTI_MEMBER_TYPE &#8212; Expands to a metafunction whose typedef 'type' is either the named type or a marker type. </p>
  30 </div>
  31 <h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2>
  32 <div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: &lt;<a class="link" href="header/boost/tti/member_type_hpp.html" title="Header &lt;boost/tti/member_type.hpp&gt;">boost/tti/member_type.hpp</a>&gt;
  33
  34 </span>BOOST_TTI_MEMBER_TYPE(name)</pre></div>
  35 <div class="refsect1">
  36 <a name="idm45456560303504"></a><h2>Description</h2>
  37 <p>name = the name of the inner type.</p>
  38 <p>generates a metafunction called "member_type_name" where 'name' is the macro parameter.       template&lt;class BOOST_TTI_TP_T,class BOOST_TTI_TP_MARKER_TYPE = boost::tti::detail::notype&gt;
  39       struct member_type_name
  40         {
  41         typedef unspecified type;
  42
  43         typedef BOOST_TTI_TP_MARKER_TYPE boost_tti_marker_type;
  44         };
  45
  46       The metafunction types and return:
  47
  48         BOOST_TTI_TP_T           = the enclosing type.
  49         BOOST_TTI_TP_MARKER_TYPE = (optional) a type to use as the marker type.
  50                           defaults to the internal boost::tti::detail::notype.
  51
  52         returns         = 'type' is the inner type of 'name' if the inner type exists
  53                           within the enclosing type, else 'type' is a marker type.
  54                           if the end-user does not specify a marker type then
  55                           an internal boost::tti::detail::notype marker type is used.
  56
  57         The metafunction also encapsulates the type of the marker type as
  58         a nested 'boost_tti_marker_type'.
  59 </p>
  60 <p>The purpose of this macro is to encapsulate the 'name' type as the typedef 'type' of a metafunction, but only if it exists within the enclosing type. This allows for an evaluation of inner type existence, without generating a compiler error, which can be used by other metafunctions in this library. </p>
  61 </div>
  62 </div>
  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 &#169; 2011-2013 Tropic Software
  66       East Inc<p>
  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>)
  69       </p>
  70 </div></td>
  71 </tr></table>
  72 <hr>
  73 <div class="spirit-nav">
  74 <a accesskey="p" href="BOOST_TT_idm46187185643920.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="header/boost/tti/member_type_hpp.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="the_type_traits_introspection_library/tti_tests.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a>
  75 </div>
  76 </body>
  77 </html>