1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> 4<title>Background</title> 5<link rel="stylesheet" href="boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="index.html" title="Safe Numerics"> 8<link rel="up" href="index.html" title="Safe Numerics"> 9<link rel="prev" href="safety_critical_embedded_controller.html" title="Safety Critical Embedded Controller"> 10<link rel="next" href="concepts.html" title="Type Requirements"> 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 href="index.html" height="164px" src="pre-boost.jpg" alt="Library Documentation Index"></td> 15<td><h2>Safe Numerics</h2></td> 16</tr></table> 17<div class="spirit-nav"> 18<a accesskey="p" href="safety_critical_embedded_controller.html"><img src="images/prev.png" alt="Prev"></a><a accesskey="u" href="index.html"><img src="images/up.png" alt="Up"></a><a accesskey="h" href="index.html"><img src="images/home.png" alt="Home"></a><a accesskey="n" href="concepts.html"><img src="images/next.png" alt="Next"></a> 19</div> 20<div class="section"> 21<div class="titlepage"><div><div><h2 class="title" style="clear: both"> 22<a name="safe_numerics.notes"></a>Background</h2></div></div></div> 23<p>This library started out as a re-implementation of the facilities 24 provided by <a href="http://safeint.codeplex.com" target="_top">David LeBlanc's SafeInt 25 Library</a>. I found this library to be well done in every way. My main 26 usage was to run unit tests for my embedded systems projects on my PC. 27 Still, from my perspective it had a few issues.</p> 28<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 29<li class="listitem"><p>It was a lot of code in one header - 6400 lines. Very unwieldy to 30 understand, modify and maintain.</p></li> 31<li class="listitem"><p>I couldn't find separate documentation other than that in the 32 header file.</p></li> 33<li class="listitem"><p>It didn't use <a href="http://www.boost.org" target="_top">Boost</a> 34 conventions for naming.</p></li> 35<li class="listitem"><p>It required porting to different compilers.</p></li> 36<li class="listitem"><p>It had a very long license associated with it.</p></li> 37<li class="listitem"><p>I could find no test suite for the library.</p></li> 38</ul></div> 39<p>Using later versions of C++ and the its standard library, template 40 metaprogramming and <a href="http://www.boost.org" target="_top">Boost 41 libraries</a> I managed to (re)implement similar functionality in under 42 2000 ? lines of code. I promoted this version as a possible submission to 43 the Boost. The feedback I received convinced me that no such library would 44 be considered acceptable to the large majority of C++ programmers. It seems 45 that the desire for maximum performance overrides any requirement that a 46 program be known to be free of bugs. By this time I had a better idea of the 47 opportunities available with the latest version of C++ (C++14) and resolved 48 to address this issue by creating a library which would provide all the 49 facilities of safe numerics at minimal runtime cost. The result is what you 50 see here. The library now consists of 7000 lines of code, approximately 50 51 separate tests and more than 60 pages of documentation and examples.</p> 52<p>Since I wrote the above, I've been contacted by David LeBlanc. He's 53 been updating his package and informs me that the latest 54 version:</p> 55<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 56<li class="listitem"><p>SafeInt does not require porting for different compilers, is 57 fully supported on gcc, clang, and Visual Studio.</p></li> 58<li class="listitem"><p>The license has been changed from MS-PL to MIT license.</p></li> 59<li class="listitem"><p>The library has had a test suite since before it was public, and 60 is now located here:</p></li> 61<li class="listitem"><p>SafeInt also has no external dependencies other than standard 62 library files, and doesn't need anything else installed to 63 work.</p></li> 64</ul></div> 65<p>His current package can now be found at in <a href="https://github.com/dcleblanc/SafeInt" target="_top">github</a>.</p> 66</div> 67<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 68<td align="left"></td> 69<td align="right"><div class="copyright-footer">Copyright © 2012-2018 Robert Ramey<p><a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">Subject to Boost 70 Software License</a></p> 71</div></td> 72</tr></table> 73<hr> 74<div class="spirit-nav"> 75<a accesskey="p" href="safety_critical_embedded_controller.html"><img src="images/prev.png" alt="Prev"></a><a accesskey="u" href="index.html"><img src="images/up.png" alt="Up"></a><a accesskey="h" href="index.html"><img src="images/home.png" alt="Home"></a><a accesskey="n" href="concepts.html"><img src="images/next.png" alt="Next"></a> 76</div> 77</body> 78</html> 79
