Files
safe_numerics/doc/html/numeric.html
Robert Ramey 1bc0b94e65 changes to implement the following:
a) made trap_exception work
b) updated manual and examples to show how to use library to eliminate runtime penalty
c) added in safe_literal
d) made corrections of various types
2015-12-21 23:14:06 -08:00

366 lines
13 KiB
HTML

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>Numeric&lt;T&gt;</title>
<link rel="stylesheet" href="boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.76.1">
<link rel="home" href="index.html" title="Safe Numerics">
<link rel="up" href="concepts.html" title="Type Requirements">
<link rel="prev" href="concepts.html" title="Type Requirements">
<link rel="next" href="integer.html" title="Integer&lt;T&gt;">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr>
<td valign="top"><img href="index.html" height="164px" src="pre-boost.jpg" alt="Library Documentation Index"></td>
<td><h2>Safe Numerics</h2></td>
</tr></table>
<div class="spirit-nav">
<a accesskey="p" href="concepts.html"><img src="images/prev.png" alt="Prev"></a><a accesskey="u" href="concepts.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="integer.html"><img src="images/next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="safe_numerics.numeric"></a>Numeric&lt;T&gt;</h3></div></div></div>
<div class="toc"><dl>
<dt><span class="section"><a href="numeric.html#idm473861967648">Description</a></span></dt>
<dt><span class="section"><a href="numeric.html#idm473861962416">Notation</a></span></dt>
<dt><span class="section"><a href="numeric.html#idm473861952624">Associated Types</a></span></dt>
<dt><span class="section"><a href="numeric.html#idm473861947552">Valid Expressions</a></span></dt>
<dt><span class="section"><a href="numeric.html#idm473861856208">Header</a></span></dt>
<dt><span class="section"><a href="numeric.html#idm473861854208">Models</a></span></dt>
</dl></div>
<div class="section">
<div class="titlepage"><div><div><h4 class="title">
<a name="idm473861967648"></a>Description</h4></div></div></div>
<p>A type is Numeric if it has the properties of a number.</p>
<p>More specifically, a type T is Numeric if there exists
specialization of <code class="computeroutput">std::numeric_limits&lt;T&gt;</code>. See the
documentation for standard library class numeric_limits. The standard
library includes such specializations for all the primitive numeric types.
Note that this concept is distinct from the C++ standard library type
traits <code class="computeroutput">is_integral</code> and <code class="computeroutput">is_arithmetic</code>. These
latter fulfill the requirement of the concept Numeric. But there are types
T which fulfill this concept for which <code class="computeroutput">is_arithmetic&lt;T&gt;::value
== false</code>. For example see
<code class="computeroutput">safe_signed_integer&lt;int&gt;</code>.</p>
</div>
<div class="section">
<div class="titlepage"><div><div><h4 class="title">
<a name="idm473861962416"></a>Notation</h4></div></div></div>
<div class="informaltable"><table class="table">
<colgroup>
<col align="left">
<col align="left">
</colgroup>
<tbody>
<tr>
<td align="left"><code class="computeroutput">T, U, V</code></td>
<td align="left">A type that is a model of the Numeric</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t, u</code></td>
<td align="left">An object of type modeling Numeric</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">os</code></td>
<td align="left">An object of type std::base_ostreami</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">is</code></td>
<td align="left">An object of type std::base_istream</td>
</tr>
</tbody>
</table></div>
</div>
<div class="section">
<div class="titlepage"><div><div><h4 class="title">
<a name="idm473861952624"></a>Associated Types</h4></div></div></div>
<div class="informaltable"><table class="table">
<colgroup>
<col align="left">
<col align="left">
</colgroup>
<tbody><tr>
<td align="left"><code class="computeroutput">std::numeric_limits&lt;T&gt;</code></td>
<td align="left">The numeric_limits class template provides a C++ program
with information about various properties of the implementation's
representation of the arithmetic types. See C++ standard
18.3.2.2.</td>
</tr></tbody>
</table></div>
</div>
<div class="section">
<div class="titlepage"><div><div><h4 class="title">
<a name="idm473861947552"></a>Valid Expressions</h4></div></div></div>
<p>In addition to the expressions defined in <a href="http://www.sgi.com/tech/stl/Assignable.html" target="_top">Assignable</a> the
following expressions must be valid. Any operations which result in
integers which cannot be represented as some Numeric type will throw an
exception.</p>
<div class="table">
<a name="idm473861945872"></a><p class="title"><b>Table&#160;1.&#160;General</b></p>
<div class="table-contents"><table class="table" summary="General">
<colgroup>
<col align="left">
<col align="left">
</colgroup>
<thead><tr>
<th align="left">Expression</th>
<th align="left">Return Value</th>
</tr></thead>
<tbody>
<tr>
<td align="left"><code class="computeroutput">std::numeric_limits&lt;T&gt;.is_bounded
</code></td>
<td align="left">true</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">std::numeric_limits&lt;T&gt;.is_specialized
</code></td>
<td align="left">true</td>
</tr>
<tr>
<td align="left"><code class="computeroutput"><td align="left">os &lt;&lt; T</td></code></td>
<td align="left">os &amp;i</td>
</tr>
<tr>
<td align="left"><code class="computeroutput"><td align="left">is &gt;&gt; T</td></code></td>
<td align="left">is &amp;</td>
</tr>
</tbody>
</table></div>
</div>
<p><br class="table-break"></p>
<div class="table">
<a name="idm473861934064"></a><p class="title"><b>Table&#160;2.&#160;Unary Operators</b></p>
<div class="table-contents"><table class="table" summary="Unary Operators">
<colgroup>
<col align="left">
<col align="left">
<col align="left">
</colgroup>
<thead><tr>
<th align="left">Expression</th>
<th align="left">Return Type</th>
<th align="left">Semantics</th>
</tr></thead>
<tbody>
<tr>
<td align="left"><code class="computeroutput">-t</code></td>
<td align="left">T</td>
<td align="left">Invert sign</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">+t</code></td>
<td align="left">T</td>
<td align="left">unary plus - a no op</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t--</code></td>
<td align="left">T</td>
<td align="left">post decrement</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t++</code></td>
<td align="left">T</td>
<td align="left">post increment</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">--t</code></td>
<td align="left">T</td>
<td align="left">pre decrement</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">++t</code></td>
<td align="left">T</td>
<td align="left">pre increment</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">~</code></td>
<td align="left">T</td>
<td align="left">complement</td>
</tr>
</tbody>
</table></div>
</div>
<br class="table-break"><div class="table">
<a name="idm473861915280"></a><p class="title"><b>Table&#160;3.&#160;Binary Operators</b></p>
<div class="table-contents"><table class="table" summary="Binary Operators">
<colgroup>
<col align="left">
<col align="left">
<col align="left">
</colgroup>
<thead><tr>
<th align="left">Expression</th>
<th align="left">Return Type</th>
<th align="left">Semantics</th>
</tr></thead>
<tbody>
<tr>
<td align="left"><code class="computeroutput">t - u</code></td>
<td align="left">V</td>
<td align="left">subtract u from t</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t + u</code></td>
<td align="left">V</td>
<td align="left">add u to t</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t * u</code></td>
<td align="left">V</td>
<td align="left">multiply t by u</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t / u</code></td>
<td align="left">T</td>
<td align="left">divide t by u</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t % u</code></td>
<td align="left">T</td>
<td align="left">t modulus u</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t &lt;&lt; u</code></td>
<td align="left">T</td>
<td align="left">shift t left u bits</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t &gt;&gt; u</code></td>
<td align="left">T</td>
<td align="left">shift t right by u bits</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t &lt; u</code></td>
<td align="left">bool</td>
<td align="left">true if t less than u, false otherwise</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t &lt;= u</code></td>
<td align="left">bool</td>
<td align="left">true if t less than or equal to u, false otherwise</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t &gt; u</code></td>
<td align="left">bool</td>
<td align="left">true if t greater than u, false otherwise</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t &gt;= u</code></td>
<td align="left">bool</td>
<td align="left">true if t greater than or equal to u, false
otherwise</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t == u</code></td>
<td align="left">bool</td>
<td align="left">true if t equal to u, false otherwise</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t != u</code></td>
<td align="left">bool</td>
<td align="left">true if t not equal to u, false otherwise</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t &amp; u</code></td>
<td align="left">V</td>
<td align="left">and of t and u padded out max # bits in t, u</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t | u</code></td>
<td align="left">V</td>
<td align="left">or of t and u padded out max # bits in t, u</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t ^ u</code></td>
<td align="left">V</td>
<td align="left">exclusive or of t and u padded out max # bits in t,
u</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t = u</code></td>
<td align="left"><code class="computeroutput">T</code></td>
<td align="left">assign value of u to t</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t += u</code></td>
<td align="left"><code class="computeroutput">T</code></td>
<td align="left">add u to t and assign to t</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t -= u</code></td>
<td align="left"><code class="computeroutput">T</code></td>
<td align="left">subtract u from t and assign to t</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t *= u</code></td>
<td align="left"><code class="computeroutput">T</code></td>
<td align="left">multiply t by u and assign to t</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t /= u</code></td>
<td align="left"><code class="computeroutput">T</code></td>
<td align="left">divide t by u and assign to t</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t &amp;= u</code></td>
<td align="left"><code class="computeroutput">T</code></td>
<td align="left">and t with u and assign to t</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t &lt;&lt;= u</code></td>
<td align="left">T</td>
<td align="left">left shift the value of t by u bits</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t &gt;&gt;= u</code></td>
<td align="left">T</td>
<td align="left">right shift the value of t by u bits</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t &amp;= u</code></td>
<td align="left">T</td>
<td align="left">and the value of t with u and assign to t</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t |= u</code></td>
<td align="left">T</td>
<td align="left">or the value of t with u and assign to t</td>
</tr>
<tr>
<td align="left"><code class="computeroutput">t ^= u</code></td>
<td align="left">T</td>
<td align="left">exclusive or the value of t with u and assign to t</td>
</tr>
</tbody>
</table></div>
</div>
<br class="table-break">
</div>
<div class="section">
<div class="titlepage"><div><div><h4 class="title">
<a name="idm473861856208"></a>Header</h4></div></div></div>
<p><a href="../../include/concept/numeric.hpp" target="_top"><code class="computeroutput">#include
&lt;safe_numerics/include/concepts/numeric.hpp&gt; </code></a></p>
</div>
<div class="section">
<div class="titlepage"><div><div><h4 class="title">
<a name="idm473861854208"></a>Models</h4></div></div></div>
<p><code class="computeroutput">int, safe_signed_integer&lt;int&gt;,
safe_signed_range&lt;int&gt;, etc.</code></p>
<p>The definition of this concept</p>
</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 &#169; 2012 Robert Ramey<p><a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">Subject to Boost
Software License</a></p>
</div></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="concepts.html"><img src="images/prev.png" alt="Prev"></a><a accesskey="u" href="concepts.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="integer.html"><img src="images/next.png" alt="Next"></a>
</div>
</body>
</html>