1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> 4<title>safe_signed_range<MIN, MAX, PP, EP> and safe_unsigned_range<MIN, MAX, PP, EP></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="types.html" title="Types"> 9<link rel="prev" href="safe.html" title="safe<T, PP, EP>"> 10<link rel="next" href="safe_literal.html" title="safe_signed_literal<Value, PP , EP> and safe_unsigned_literal<Value, PP, EP>"> 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="safe.html"><img src="images/prev.png" alt="Prev"></a><a accesskey="u" href="types.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="safe_literal.html"><img src="images/next.png" alt="Next"></a> 19</div> 20<div class="section"> 21<div class="titlepage"><div><div><h3 class="title"> 22<a name="safe_numerics.safe_range"></a>safe_signed_range<MIN, MAX, PP, EP> and 23 safe_unsigned_range<MIN, MAX, PP, EP></h3></div></div></div> 24<div class="toc"><dl class="toc"> 25<dt><span class="section"><a href="safe_range.html#idm130203244016">Description</a></span></dt> 26<dt><span class="section"><a href="safe_range.html#idm130203241136">Notation</a></span></dt> 27<dt><span class="section"><a href="safe_range.html#idm130203233776">Associated Types</a></span></dt> 28<dt><span class="section"><a href="safe_range.html#idm130203226688">Template Parameters</a></span></dt> 29<dt><span class="section"><a href="safe_range.html#idm130203205424">Model of</a></span></dt> 30<dt><span class="section"><a href="safe_range.html#idm130203186512">Valid Expressions</a></span></dt> 31<dt><span class="section"><a href="safe_range.html#idm130203184224">Example of use</a></span></dt> 32<dt><span class="section"><a href="safe_range.html#idm130203099968">Header</a></span></dt> 33</dl></div> 34<div class="section"> 35<div class="titlepage"><div><div><h4 class="title"> 36<a name="idm130203244016"></a>Description</h4></div></div></div> 37<p>This type holds a signed or unsigned integer in the closed range 38 [MIN, MAX]. A <code class="computeroutput">safe_signed_range<MIN, MAX, PP, EP></code> or 39 <code class="computeroutput">safe_unsigned_range<MIN, MAX, PP, EP></code> can be used 40 anywhere an arithmetic type is permitted. Any expression which uses either 41 of these types is guaranteed to return an arithmetically correct value or 42 to trap in some way.</p> 43</div> 44<div class="section"> 45<div class="titlepage"><div><div><h4 class="title"> 46<a name="idm130203241136"></a>Notation</h4></div></div></div> 47<div class="informaltable"><table class="table"> 48<colgroup> 49<col align="left"> 50<col align="left"> 51</colgroup> 52<thead><tr> 53<th align="left">Symbol</th> 54<th align="left">Description</th> 55</tr></thead> 56<tbody><tr> 57<td align="left"><code class="computeroutput">MIN, MAX</code></td> 58<td align="left">Minimum and maximum values that the range can 59 represent.</td> 60</tr></tbody> 61</table></div> 62</div> 63<div class="section"> 64<div class="titlepage"><div><div><h4 class="title"> 65<a name="idm130203233776"></a>Associated Types</h4></div></div></div> 66<div class="informaltable"><table class="table"> 67<colgroup> 68<col align="left"> 69<col align="left"> 70</colgroup> 71<tbody> 72<tr> 73<td align="left"><code class="computeroutput">PP</code></td> 74<td align="left">Promotion Policy. A type which specifies the result type of 75 an expression using safe types.</td> 76</tr> 77<tr> 78<td align="left"><code class="computeroutput">EP</code></td> 79<td align="left">Exception Policy. A type containing members which are 80 called when a correct result cannot be returned</td> 81</tr> 82</tbody> 83</table></div> 84</div> 85<div class="section"> 86<div class="titlepage"><div><div><h4 class="title"> 87<a name="idm130203226688"></a>Template Parameters</h4></div></div></div> 88<div class="informaltable"><table class="table"> 89<colgroup> 90<col align="left"> 91<col align="left"> 92<col align="left"> 93</colgroup> 94<thead><tr> 95<th align="left">Parameter</th> 96<th align="left">Requirements</th> 97<th align="left">Description</th> 98</tr></thead> 99<tbody> 100<tr> 101<td align="left"><code class="computeroutput">MIN</code></td> 102<td align="left">must be a non-negative literal</td> 103<td align="left">The minimum non-negative integer value that this type may 104 hold</td> 105</tr> 106<tr> 107<td align="left"><code class="computeroutput">MAX</code></td> 108<td align="left">must be a non-negative literal</td> 109<td align="left">The maximum non-negative integer value that this type may 110 hold</td> 111</tr> 112<tr> 113<td align="left"> </td> 114<td align="left">MIN <= MAX</td> 115<td align="left">must be a valid closed range</td> 116</tr> 117<tr> 118<td align="left"><code class="computeroutput">PP</code></td> 119<td align="left"><a class="link" href="numeric.html" title="Numeric<T>">PromotionPolicy<PP></a></td> 120<td align="left"><p>Default value is <a class="link" href="promotion_policies/native.html" title="native"><code class="computeroutput">boost::numeric::native</code></a></p></td> 121</tr> 122<tr> 123<td align="left"><code class="computeroutput">EP</code></td> 124<td align="left"><a class="link" href="numeric.html" title="Numeric<T>">Exception 125 Policy<EP></a></td> 126<td align="left"><p>Default value is <a class="link" href="exception_policies.html#safe_numerics.exception_policies.default_exception_policy"><code class="computeroutput">boost::numeric::default_exception_policy</code></a></p></td> 127</tr> 128</tbody> 129</table></div> 130</div> 131<div class="section"> 132<div class="titlepage"><div><div><h4 class="title"> 133<a name="idm130203205424"></a>Model of</h4></div></div></div> 134<p><a class="link" href="numeric.html" title="Numeric<T>">Integer</a></p> 135<p><a class="link" href="safe_numeric_concept.html" title="SafeNumeric<T>">SafeNumeric</a></p> 136</div> 137<div class="section"> 138<div class="titlepage"><div><div><h4 class="title"> 139<a name="idm130203186512"></a>Valid Expressions</h4></div></div></div> 140<p>Implements all expressions and only those expressions defined by the 141 <a class="link" href="safe_numeric_concept.html" title="SafeNumeric<T>">SafeNumeric</a> type 142 requirements. Thus, the result type of such an expression will be another 143 safe type. The actual type of the result of such an expression will depend 144 upon the specific promotion policy template parameter.</p> 145</div> 146<div class="section"> 147<div class="titlepage"><div><div><h4 class="title"> 148<a name="idm130203184224"></a>Example of use</h4></div></div></div> 149<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">type_traits</span><span class="special">></span> 150<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">safe_numerics</span><span class="special">/</span><span class="identifier">safe_integer</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 151<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">safe_numerics</span><span class="special">/</span><span class="identifier">safe_integer_range</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 152 153<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">safe_numerics</span><span class="special">/</span><span class="identifier">utility</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 154 155<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">safe_numerics</span><span class="special">;</span> 156 157<span class="keyword">void</span> <span class="identifier">f</span><span class="special">(</span><span class="special">)</span><span class="special">{</span> 158 <span class="identifier">safe_unsigned_range</span><span class="special"><</span><span class="number">7</span><span class="special">,</span> <span class="number">24</span><span class="special">></span> <span class="identifier">i</span><span class="special">;</span> 159 <span class="comment">// since the range is included in [0,255], the underlying type of i </span> 160 <span class="comment">// will be an unsigned char.</span> 161 <span class="identifier">i</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="comment">// throws out_of_range exception</span> 162 <span class="identifier">i</span> <span class="special">=</span> <span class="number">9</span><span class="special">;</span> <span class="comment">// ok</span> 163 <span class="identifier">i</span> <span class="special">*=</span> <span class="number">9</span><span class="special">;</span> <span class="comment">// throws out_of_range exception</span> 164 <span class="identifier">i</span> <span class="special">=</span> <span class="special">-</span><span class="number">1</span><span class="special">;</span> <span class="comment">// throws out_of_range exception</span> 165 <span class="identifier">std</span><span class="special">::</span><span class="identifier">uint8_t</span> <span class="identifier">j</span> <span class="special">=</span> <span class="number">4</span><span class="special">;</span> 166 <span class="keyword">auto</span> <span class="identifier">k</span> <span class="special">=</span> <span class="identifier">i</span> <span class="special">+</span> <span class="identifier">j</span><span class="special">;</span> 167 168 <span class="comment">// if either or both types are safe types, the result is a safe type</span> 169 <span class="comment">// determined by promotion policy. In this instance</span> 170 <span class="comment">// the range of i is [7, 24] and the range of j is [0,255].</span> 171 <span class="comment">// so the type of k will be a safe type with a range of [7,279]</span> 172 <span class="identifier">static_assert</span><span class="special">(</span> 173 <span class="identifier">is_safe</span><span class="special"><</span><span class="keyword">decltype</span><span class="special">(</span><span class="identifier">k</span><span class="special">)</span><span class="special">></span><span class="special">::</span><span class="identifier">value</span> 174 <span class="special">&&</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span><span class="special"><</span><span class="keyword">decltype</span><span class="special">(</span><span class="identifier">k</span><span class="special">)</span><span class="special">></span><span class="special">::</span><span class="identifier">min</span><span class="special">(</span><span class="special">)</span> <span class="special">==</span> <span class="number">7</span> 175 <span class="special">&&</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span><span class="special"><</span><span class="keyword">decltype</span><span class="special">(</span><span class="identifier">k</span><span class="special">)</span><span class="special">></span><span class="special">::</span><span class="identifier">max</span><span class="special">(</span><span class="special">)</span> <span class="special">==</span> <span class="number">279</span><span class="special">,</span> 176 <span class="string">"k is a safe range of [7,279]"</span> 177 <span class="special">)</span><span class="special">;</span> 178<span class="special">}</span> 179 180<span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="special">)</span><span class="special">{</span><span class="special">}</span> 181</pre> 182</div> 183<div class="section"> 184<div class="titlepage"><div><div><h4 class="title"> 185<a name="idm130203099968"></a>Header</h4></div></div></div> 186<p><code class="filename"><a href="../../include/safe_range.hpp" target="_top">#include 187 <boost/numeric/safe_numerics/safe_range.hpp></a></code></p> 188</div> 189</div> 190<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 191<td align="left"></td> 192<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 193 Software License</a></p> 194</div></td> 195</tr></table> 196<hr> 197<div class="spirit-nav"> 198<a accesskey="p" href="safe.html"><img src="images/prev.png" alt="Prev"></a><a accesskey="u" href="types.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="safe_literal.html"><img src="images/next.png" alt="Next"></a> 199</div> 200</body> 201</html> 202
