| <html> |
| <head> |
| <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> |
| <title>Mixing sources with RTTI on and RTTI off</title> |
| <link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> |
| <meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> |
| <link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> |
| <link rel="up" href="../boost_typeindex.html" title="Chapter 34. Boost.TypeIndex 4.0"> |
| <link rel="prev" href="rtti_emulation_limitations.html" title="RTTI emulation limitations"> |
| <link rel="next" href="acknowledgements.html" title="Acknowledgements"> |
| </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="rtti_emulation_limitations.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../boost_typeindex.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="acknowledgements.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_typeindex.mixing_sources_with_rtti_on_and_"></a><a class="link" href="mixing_sources_with_rtti_on_and_.html" title="Mixing sources with RTTI on and RTTI off">Mixing |
| sources with RTTI on and RTTI off</a> |
| </h2></div></div></div> |
| <p> |
| Linking a binary from source files that were compiled with different RTTI flags |
| is not a very good idea and may lead to a lot of surprises. However if there |
| is a very strong need, TypeIndex library provides a solution for mixing sources: |
| just define <code class="computeroutput"><a class="link" href="../BOOST_TYPE_INDEX_FORCE_NO_RTTI_COMPATIBILITY.html" title="Macro BOOST_TYPE_INDEX_FORCE_NO_RTTI_COMPATIBILITY">BOOST_TYPE_INDEX_FORCE_NO_RTTI_COMPATIBILITY</a></code> |
| macro. This would lead to usage of same type_index class (<code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">typeindex</span><span class="special">::</span><span class="identifier">ctti_type_index</span></code> |
| or <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">typeindex</span><span class="special">::</span><span class="identifier">stl_type_index</span></code>) all around the project. |
| </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> |
| Do not forget to rebuild <span class="bold"><strong>all</strong></span> the projects |
| with <code class="computeroutput"><span class="identifier">BOOST_TYPE_INDEX_FORCE_NO_RTTI_COMPATIBILITY</span></code> |
| macro defined |
| </p></td></tr> |
| </table></div> |
| <p> |
| You must know that linking RTTI on and RTTI off binaries may succeed even without |
| defining the <code class="computeroutput"><span class="identifier">BOOST_TYPE_INDEX_FORCE_NO_RTTI_COMPATIBILITY</span></code> |
| macro, but that does not mean that you'll get a working binary. Such actions |
| may break the One Definition Rule. Take a look at the table below, that shows |
| how the <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">type_index</span> <span class="identifier">get_integer</span><span class="special">();</span></code> function will look like with different RTTI |
| flags: |
| </p> |
| <div class="informaltable"> |
| <a name="boost_typeindex.mixing_sources_with_rtti_on_and_.diffs"></a><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| RTTI on |
| </p> |
| </th> |
| <th> |
| <p> |
| RTTI off |
| </p> |
| </th> |
| </tr></thead> |
| <tbody><tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">typeindex</span><span class="special">::</span><span class="identifier">stl_type_index</span> <span class="identifier">get_integer</span><span class="special">();</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">typeindex</span><span class="special">::</span><span class="identifier">ctti_type_index</span> <span class="identifier">get_integer</span><span class="special">();</span></code> |
| </p> |
| </td> |
| </tr></tbody> |
| </table> |
| </div> |
| <p> |
| Such differences are usually not detected by linker and lead to errors at runtime. |
| </p> |
| <div class="warning"><table border="0" summary="Warning"> |
| <tr> |
| <td rowspan="2" align="center" valign="top" width="25"><img alt="[Warning]" src="../../../doc/src/images/warning.png"></td> |
| <th align="left">Warning</th> |
| </tr> |
| <tr><td align="left" valign="top"><p> |
| Even with <code class="computeroutput"><span class="identifier">BOOST_TYPE_INDEX_FORCE_NO_RTTI_COMPATIBILITY</span></code> |
| defined there is no guarantee that everything will be OK. Libraries that |
| use their own workarounds for disabled RTTI may fail to link or to work correctly. |
| </p></td></tr> |
| </table></div> |
| </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 © 2012-2014 Antony Polukhin<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="rtti_emulation_limitations.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../boost_typeindex.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="acknowledgements.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> |
| </div> |
| </body> |
| </html> |
