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| 24 | </div> | |
| 25 | <div class="section"> | |
| 26 | <div class="titlepage"><div><div><h2 class="title" style="clear: both"> | |
| 27 | <a name="boost_integer.minmax"></a><a class="link" href="minmax.html" title="Compile time min/max calculation">Compile time min/max calculation</a> | |
| 28 | </h2></div></div></div> | |
| 29 | <div class="toc"><dl class="toc"> | |
| 30 | <dt><span class="section"><a href="minmax.html#boost_integer.minmax.synopsis">Synopsis</a></span></dt> | |
| 31 | <dt><span class="section"><a href="minmax.html#boost_integer.minmax.usage">Usage</a></span></dt> | |
| 32 | <dt><span class="section"><a href="minmax.html#boost_integer.minmax.example">Example</a></span></dt> | |
| 33 | <dt><span class="section"><a href="minmax.html#boost_integer.minmax.demonstration_program">Demonstration | |
| 34 | Program</a></span></dt> | |
| 35 | <dt><span class="section"><a href="minmax.html#boost_integer.minmax.rationale">Rationale</a></span></dt> | |
| 36 | <dt><span class="section"><a href="minmax.html#boost_integer.minmax.credits">Credits</a></span></dt> | |
| 37 | </dl></div> | |
| 38 | <p> | |
| 39 | The class templates in <a href="../../../../../boost/integer/static_min_max.hpp" target="_top"><boost/integer/static_min_max.hpp></a> | |
| 40 | provide a compile-time evaluation of the minimum or maximum of two integers. | |
| 41 | These facilities are useful for generic programming problems. | |
| 42 | </p> | |
| 43 | <div class="section"> | |
| 44 | <div class="titlepage"><div><div><h3 class="title"> | |
| 45 | <a name="boost_integer.minmax.synopsis"></a><a class="link" href="minmax.html#boost_integer.minmax.synopsis" title="Synopsis">Synopsis</a> | |
| 46 | </h3></div></div></div> | |
| 47 | <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> | |
| 48 | <span class="special">{</span> | |
| 49 | ||
| 50 | <span class="keyword">typedef</span> <span class="emphasis"><em>implementation-defined</em></span> <span class="identifier">static_min_max_signed_type</span><span class="special">;</span> | |
| 51 | <span class="keyword">typedef</span> <span class="emphasis"><em>implementation-defined</em></span> <span class="identifier">static_min_max_unsigned_type</span><span class="special">;</span> | |
| 52 | ||
| 53 | <span class="keyword">template</span> <span class="special"><</span><span class="identifier">static_min_max_signed_type</span> <span class="identifier">Value1</span><span class="special">,</span> <span class="identifier">static_min_max_signed_type</span> <span class="identifier">Value2</span> <span class="special">></span> | |
| 54 | <span class="keyword">struct</span> <span class="identifier">static_signed_min</span><span class="special">;</span> | |
| 55 | ||
| 56 | <span class="keyword">template</span> <span class="special"><</span><span class="identifier">static_min_max_signed_type</span> <span class="identifier">Value1</span><span class="special">,</span> <span class="identifier">static_min_max_signed_type</span> <span class="identifier">Value2</span><span class="special">></span> | |
| 57 | <span class="keyword">struct</span> <span class="identifier">static_signed_max</span><span class="special">;</span> | |
| 58 | ||
| 59 | <span class="keyword">template</span> <span class="special"><</span><span class="identifier">static_min_max_unsigned_type</span> <span class="identifier">Value1</span><span class="special">,</span> <span class="identifier">static_min_max_unsigned_type</span> <span class="identifier">Value2</span><span class="special">></span> | |
| 60 | <span class="keyword">struct</span> <span class="identifier">static_unsigned_min</span><span class="special">;</span> | |
| 61 | ||
| 62 | <span class="keyword">template</span> <span class="special"><</span><span class="identifier">static_min_max_unsigned_type</span> <span class="identifier">Value1</span><span class="special">,</span> <span class="identifier">static_min_max_unsigned_type</span> <span class="identifier">Value2</span><span class="special">></span> | |
| 63 | <span class="keyword">struct</span> <span class="identifier">static_unsigned_max</span><span class="special">;</span> | |
| 64 | ||
| 65 | <span class="special">}</span> | |
| 66 | </pre> | |
| 67 | </div> | |
| 68 | <div class="section"> | |
| 69 | <div class="titlepage"><div><div><h3 class="title"> | |
| 70 | <a name="boost_integer.minmax.usage"></a><a class="link" href="minmax.html#boost_integer.minmax.usage" title="Usage">Usage</a> | |
| 71 | </h3></div></div></div> | |
| 72 | <p> | |
| 73 | The four class templates provide the combinations for finding the minimum | |
| 74 | or maximum of two <code class="literal">signed</code> or <code class="literal">unsigned</code> | |
| 75 | (<code class="literal">long</code>) parameters, <span class="emphasis"><em>Value1</em></span> and <span class="emphasis"><em>Value2</em></span>, | |
| 76 | at compile-time. Each template has a single static data member, <code class="literal">value</code>, | |
| 77 | which is set to the respective minimum or maximum of the template's parameters. | |
| 78 | </p> | |
| 79 | </div> | |
| 80 | <div class="section"> | |
| 81 | <div class="titlepage"><div><div><h3 class="title"> | |
| 82 | <a name="boost_integer.minmax.example"></a><a class="link" href="minmax.html#boost_integer.minmax.example" title="Example">Example</a> | |
| 83 | </h3></div></div></div> | |
| 84 | <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">integer</span><span class="special">/</span><span class="identifier">static_min_max</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> | |
| 85 | ||
| 86 | <span class="keyword">template</span> <span class="special"><</span> <span class="keyword">unsigned</span> <span class="keyword">long</span> <span class="identifier">AddendSize1</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="keyword">long</span> <span class="identifier">AddendSize2</span> <span class="special">></span> | |
| 87 | <span class="keyword">class</span> <span class="identifier">adder</span> | |
| 88 | <span class="special">{</span> | |
| 89 | <span class="keyword">public</span><span class="special">:</span> | |
| 90 | <span class="keyword">static</span> <span class="keyword">unsigned</span> <span class="keyword">long</span> <span class="keyword">const</span> <span class="identifier">addend1_size</span> <span class="special">=</span> <span class="identifier">AddendSize1</span><span class="special">;</span> | |
| 91 | <span class="keyword">static</span> <span class="keyword">unsigned</span> <span class="keyword">long</span> <span class="keyword">const</span> <span class="identifier">addend2_size</span> <span class="special">=</span> <span class="identifier">AddendSize2</span><span class="special">;</span> | |
| 92 | <span class="keyword">static</span> <span class="keyword">unsigned</span> <span class="keyword">long</span> <span class="keyword">const</span> <span class="identifier">sum_size</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">static_unsigned_max</span><span class="special"><</span><span class="identifier">AddendSize1</span><span class="special">,</span> <span class="identifier">AddendSize2</span><span class="special">>::</span><span class="identifier">value</span> <span class="special">+</span> <span class="number">1</span><span class="special">;</span> | |
| 93 | ||
| 94 | <span class="keyword">typedef</span> <span class="keyword">int</span> <span class="identifier">addend1_type</span><span class="special">[</span> <span class="identifier">addend1_size</span> <span class="special">];</span> | |
| 95 | <span class="keyword">typedef</span> <span class="keyword">int</span> <span class="identifier">addend2_type</span><span class="special">[</span> <span class="identifier">addend2_size</span> <span class="special">];</span> | |
| 96 | <span class="keyword">typedef</span> <span class="keyword">int</span> <span class="identifier">sum_type</span><span class="special">[</span> <span class="identifier">sum_size</span> <span class="special">];</span> | |
| 97 | ||
| 98 | <span class="keyword">void</span> <span class="keyword">operator</span> <span class="special">()(</span> <span class="identifier">addend1_type</span> <span class="keyword">const</span> <span class="special">&</span><span class="identifier">a1</span><span class="special">,</span> <span class="identifier">addend2_type</span> <span class="keyword">const</span> <span class="special">&</span><span class="identifier">a2</span><span class="special">,</span> <span class="identifier">sum_type</span> <span class="special">&</span><span class="identifier">s</span> <span class="special">)</span> <span class="keyword">const</span><span class="special">;</span> | |
| 99 | <span class="special">};</span> | |
| 100 | ||
| 101 | <span class="comment">//...</span> | |
| 102 | ||
| 103 | <span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> | |
| 104 | <span class="special">{</span> | |
| 105 | <span class="keyword">int</span> <span class="keyword">const</span> <span class="identifier">a1</span><span class="special">[]</span> <span class="special">=</span> <span class="special">{</span> <span class="number">0</span><span class="special">,</span> <span class="number">4</span><span class="special">,</span> <span class="number">3</span> <span class="special">};</span> <span class="comment">// 340</span> | |
| 106 | <span class="keyword">int</span> <span class="keyword">const</span> <span class="identifier">a2</span><span class="special">[]</span> <span class="special">=</span> <span class="special">{</span> <span class="number">9</span><span class="special">,</span> <span class="number">8</span> <span class="special">};</span> <span class="comment">// 89</span> | |
| 107 | <span class="keyword">int</span> <span class="identifier">s</span><span class="special">[</span> <span class="number">4</span> <span class="special">];</span> | |
| 108 | <span class="identifier">adder</span><span class="special"><</span><span class="number">3</span><span class="special">,</span><span class="number">2</span><span class="special">></span> <span class="identifier">obj</span><span class="special">;</span> | |
| 109 | ||
| 110 | <span class="identifier">obj</span><span class="special">(</span> <span class="identifier">a1</span><span class="special">,</span> <span class="identifier">a2</span><span class="special">,</span> <span class="identifier">s</span> <span class="special">);</span> <span class="comment">// 's' should be 429 or { 9, 2, 4, 0 }</span> | |
| 111 | <span class="comment">//...</span> | |
| 112 | <span class="special">}</span> | |
| 113 | </pre> | |
| 114 | </div> | |
| 115 | <div class="section"> | |
| 116 | <div class="titlepage"><div><div><h3 class="title"> | |
| 117 | <a name="boost_integer.minmax.demonstration_program"></a><a class="link" href="minmax.html#boost_integer.minmax.demonstration_program" title="Demonstration Program">Demonstration | |
| 118 | Program</a> | |
| 119 | </h3></div></div></div> | |
| 120 | <p> | |
| 121 | The program <a href="../../../test/static_min_max_test.cpp" target="_top">static_min_max_test.cpp</a> | |
| 122 | is a simplistic demonstration of various comparisons using the compile-time | |
| 123 | extrema class templates. | |
| 124 | </p> | |
| 125 | </div> | |
| 126 | <div class="section"> | |
| 127 | <div class="titlepage"><div><div><h3 class="title"> | |
| 128 | <a name="boost_integer.minmax.rationale"></a><a class="link" href="minmax.html#boost_integer.minmax.rationale" title="Rationale">Rationale</a> | |
| 129 | </h3></div></div></div> | |
| 130 | <p> | |
| 131 | Sometimes the minimum or maximum of several values needs to be found for | |
| 132 | later compile-time processing, <span class="emphasis"><em>e.g.</em></span> for a bound for | |
| 133 | another class template. | |
| 134 | </p> | |
| 135 | </div> | |
| 136 | <div class="section"> | |
| 137 | <div class="titlepage"><div><div><h3 class="title"> | |
| 138 | <a name="boost_integer.minmax.credits"></a><a class="link" href="minmax.html#boost_integer.minmax.credits" title="Credits">Credits</a> | |
| 139 | </h3></div></div></div> | |
| 140 | <p> | |
| 141 | The author of the Boost compile-time extrema class templates is <a href="http://www.boost.org/people/daryle_walker.html" target="_top">Daryle | |
| 142 | Walker</a>. | |
| 143 | </p> | |
| 144 | </div> | |
| 145 | </div> | |
| 146 | <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> | |
| 147 | <td align="left"></td> | |
| 148 | <td align="right"><div class="copyright-footer">Copyright © 2001-2009 Beman | |
| 149 | Dawes, Daryle Walker, Gennaro Prota, John Maddock<p> | |
| 150 | Distributed under the Boost Software License, Version 1.0. (See accompanying | |
| 151 | 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>) | |
| 152 | </p> | |
| 153 | </div></td> | |
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