<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>History and Acknowledgements</title> <link rel="stylesheet" href="../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="../foreach.html" title="Chapter 6. Boost.Foreach"> <link rel="prev" href="pitfalls.html" title="Pitfalls"> <link rel="next" href="../function.html" title="Chapter 7. Boost.Function"> </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="pitfalls.html"><img src="../../../doc/html/images/prev.png" alt="Prev"></a><a accesskey="u" href="../foreach.html"><img src="../../../doc/html/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/html/images/home.png" alt="Home"></a><a accesskey="n" href="../function.html"><img src="../../../doc/html/images/next.png" alt="Next"></a> </div> <div class="section" title="History and Acknowledgements"> <div class="titlepage"><div><div><h2 class="title" style="clear: both"> <a name="foreach.history_and_acknowledgements"></a><a class="link" href="history_and_acknowledgements.html" title="History and Acknowledgements">History and Acknowledgements</a> </h2></div></div></div> <a name="foreach.history_and_acknowledgements.history"></a><h3> <a name="id865057"></a> <a class="link" href="history_and_acknowledgements.html#foreach.history_and_acknowledgements.history">History</a> </h3> <p> The ideas for <code class="literal">BOOST_FOREACH</code> began life in the Visual C++ group at Microsoft during the early phases of the design for C++/CLI. Whether to add a dedicated "foreach" looping construct to the language was an open question at the time. As a mental exercise, Anson Tsao sent around some proof-of-concept code which demonstrated that a pure library solution might be possible. The code was written in the proposed C++/CLI dialect of the time, for which there was no compiler as of yet. I was intrigued by the possibility, and I ported his code to Managed C++ and got it working. We worked together to refine the idea and eventually published an article about it in the November 2003 issue of the <a href="http://www.cuj.com" target="_top">CUJ</a>. </p> <p> After leaving Microsoft, I revisited the idea of a looping construct. I reimplemented the macro from scratch in standard C++, corrected some shortcomings of the CUJ version and rechristened it <code class="literal">BOOST_FOREACH</code>. In October of 2003 I began a discussion about it on the Boost developers list, where it met with a luke-warm reception. I dropped the issue until December 2004, when I reimplemented <code class="literal">BOOST_FOREACH</code> yet again. The new version only evaluated its sequence expression once and correctly handled both lvalue and rvalue sequence expressions. It was built on top of the recently accepted <a href="../../../libs/range/index.html" target="_top">Boost.Range</a> library, which increased its portability. This was the version that, on Dec. 12 2004, I finally submitted to Boost for review. It was accepted into Boost on May 5, 2005. </p> <a name="foreach.history_and_acknowledgements.acknowledgements"></a><h3> <a name="id865128"></a> <a class="link" href="history_and_acknowledgements.html#foreach.history_and_acknowledgements.acknowledgements">Acknowledgements</a> </h3> <p> Thanks go out to Anson Tsao of Microsoft for coming up with the idea and demonstrating its feasibility. I would also like to thank <a href="http://boost.org/people/thorsten_ottosen.html" target="_top">Thorsten Ottosen</a> for the <a href="../../../libs/range/index.html" target="_top">Boost.Range</a> library, on which the current version of <code class="literal">BOOST_FOREACH</code> is built. Finally, I'd like to thank Russell Hind, Alisdair Meredith and Stefan Slapeta for their help porting to various compilers. </p> <a name="foreach.history_and_acknowledgements.further_reading"></a><h3> <a name="id865178"></a> <a class="link" href="history_and_acknowledgements.html#foreach.history_and_acknowledgements.further_reading">Further Reading</a> </h3> <p> For more information about how <code class="literal">BOOST_FOREACH</code> works, you may refer to the article <a href="http://www.artima.com/cppsource/foreach.html" target="_top"><span class="quote">“<span class="quote">Conditional Love</span>”</span></a> at <a href="http://www.artima.com/cppsource/" target="_top">The C++ Source</a>. </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 © 2004 Eric Niebler<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="pitfalls.html"><img src="../../../doc/html/images/prev.png" alt="Prev"></a><a accesskey="u" href="../foreach.html"><img src="../../../doc/html/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/html/images/home.png" alt="Home"></a><a accesskey="n" href="../function.html"><img src="../../../doc/html/images/next.png" alt="Next"></a> </div> </body> </html>