| <html> |
| <head> |
| <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> |
| <title>Implementation</title> |
| <link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> |
| <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> |
| <link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> |
| <link rel="up" href="../boost_tr1.html" title="Chapter 23. Boost.TR1"> |
| <link rel="prev" href="header_list.html" title="TR1 By Header"> |
| <link rel="next" href="testing.html" title="Testing"> |
| </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="header_list.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../boost_tr1.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="testing.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> |
| </div> |
| <div class="section"> |
| <div class="titlepage"><div><div><h2 class="title" style="clear: both"> |
| <a name="boost_tr1.implementation"></a><a class="link" href="implementation.html" title="Implementation">Implementation</a> |
| </h2></div></div></div> |
| <p> |
| When Boost.TR1 is <a class="link" href="config.html" title="Configuration">configured</a> to make |
| use of your standard library's native TR1 implementation, then it doesn't do |
| very much: it just includes the appropriate header. |
| </p> |
| <p> |
| When Boost.TR1 is using the Boost implementation of a particular component, |
| then it includes the appropriate Boost header(s) and imports the necessary |
| declarations in <code class="computeroutput"><span class="keyword">namespace</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">tr1</span></code> with |
| using declarations. Note that only those declarations that are part of the |
| standard are imported: the implementation is deliberately quite strict about |
| not including any Boost-specific extensions in <code class="computeroutput"><span class="keyword">namespace</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">tr1</span></code>, in order to catch any portability errors |
| in user code. If you really need to use Boost-specific extensions then you |
| should include the Boost headers directly and use the declarations in <code class="computeroutput"><span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span></code> instead. Note that this style of implementation |
| is not completely standards-conforming, in particular it is not possible to |
| add user-defined template specializations of TR1 components into <code class="computeroutput"><span class="keyword">namespace</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">tr1</span></code>. There |
| are also one or two Boost libraries that are not yet fully standards conforming, |
| any such non-conformities are documented in <a class="link" href="subject_list.html" title="TR1 By Subject">the |
| TR1 by subject section</a>. Hopefully, occurrences of non-standard behavior |
| should be extremely rare in practice however. |
| </p> |
| <p> |
| If you use the standard conforming header includes (in <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">tr1</span><span class="special">/</span><span class="identifier">tr1</span></code>) then these header names can sometimes |
| conflict with existing standard library headers (for example <code class="computeroutput"><span class="identifier">shared_ptr</span></code> is added to the existing standard |
| library header <code class="computeroutput"><span class="special"><</span><span class="identifier">memory</span><span class="special">></span></code> rather than it's own header). These headers |
| forward on to your existing standard library header in one of two ways: for |
| gcc it uses <code class="computeroutput"><span class="preprocessor">#include_next</span></code>, |
| and for other compilers it uses the macro <code class="computeroutput"><span class="identifier">BOOST_TR1_STD_HEADER</span><span class="special">(</span><span class="identifier">header</span><span class="special">)</span></code> |
| (defined in <a href="../../../boost/tr1/detail/config.hpp" target="_top">boost/tr1/detail/config.hpp</a>) |
| which evaluates to <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special"><../</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">header</span><span class="special">></span></code>. |
| This should work "straight out the box" for most compilers, but does |
| mean that these headers should <span class="bold"><strong>never</strong></span> be placed |
| inside a directory called "include" that is already in your compiler's |
| search path. |
| </p> |
| </div> |
| <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> |
| <td align="left"></td> |
| <td align="right"><div class="copyright-footer">Copyright © 2005 John Maddock<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></td> |
| </tr></table> |
| <hr> |
| <div class="spirit-nav"> |
| <a accesskey="p" href="header_list.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../boost_tr1.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="testing.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> |
| </div> |
| </body> |
| </html> |
