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| <div class="section" title="bounds<> traits class"> |
| <div class="titlepage"><div><div><h2 class="title" style="clear: both"> |
| <a name="boost_numericconversion.bounds___traits_class"></a><a class="link" href="bounds___traits_class.html" title="bounds<> traits class">bounds<> |
| traits class</a> |
| </h2></div></div></div> |
| <div class="toc"><dl> |
| <dt><span class="section"><a href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.introduction">Introduction</a></span></dt> |
| <dt><span class="section"><a href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.traits_class_bounds_n_">traits |
| class bounds<N></a></span></dt> |
| <dt><span class="section"><a href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.examples">Examples</a></span></dt> |
| </dl></div> |
| <div class="section" title="Introduction"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="boost_numericconversion.bounds___traits_class.introduction"></a><a class="link" href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.introduction" title="Introduction">Introduction</a> |
| </h3></div></div></div> |
| <p> |
| To determine the ranges of numeric types with <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span></code> |
| [18.2.1], different syntax have to be used depending on numeric type. Specifically, |
| <code class="computeroutput"><span class="identifier">numeric_limits</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">min</span><span class="special">()</span></code> for |
| integral types returns the minimum finite value, whereas for floating point |
| types it returns the minimum positive normalized value. The difference in |
| semantics makes client code unnecessarily complex and error prone. |
| </p> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">bounds</span><span class="special"><></span></code> |
| provides a consistent interface for retrieving the maximum finite value, |
| the minimum finite value and the minimum positive normalized value (0 for |
| integral types) for numeric types. The selection of implementation is performed |
| at compile time, so there is no runtime overhead. |
| </p> |
| </div> |
| <div class="section" title="traits class bounds<N>"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="boost_numericconversion.bounds___traits_class.traits_class_bounds_n_"></a><a class="link" href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.traits_class_bounds_n_" title="traits class bounds<N>">traits |
| class bounds<N></a> |
| </h3></div></div></div> |
| <pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">N</span><span class="special">></span> |
| <span class="keyword">struct</span> <span class="identifier">bounds</span> |
| <span class="special">{</span> |
| <span class="keyword">static</span> <span class="identifier">N</span> <span class="identifier">lowest</span> <span class="special">()</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">implementation_defined</span><span class="special">;</span> <span class="special">}</span> |
| <span class="keyword">static</span> <span class="identifier">N</span> <span class="identifier">highest</span> <span class="special">()</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">implementation_defined</span><span class="special">;</span> <span class="special">}</span> |
| <span class="keyword">static</span> <span class="identifier">N</span> <span class="identifier">smallest</span><span class="special">()</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">implementation_defined</span><span class="special">;</span> <span class="special">}</span> |
| <span class="special">};</span> |
| </pre> |
| <a name="boost_numericconversion.bounds___traits_class.traits_class_bounds_n_.members"></a><h5> |
| <a name="id565414"></a> |
| <a class="link" href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.traits_class_bounds_n_.members">Members</a> |
| </h5> |
| <div class="blockquote"><blockquote class="blockquote"> |
| <p> |
| </p> |
| <p> |
| <code class="computeroutput"><span class="identifier">lowest</span><span class="special">()</span></code> |
| </p> |
| <p> |
| </p> |
| </blockquote></div> |
| <p> |
| Returns the minimum finite value, equivalent to <code class="computeroutput"><span class="identifier">numeric_limits</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">min</span><span class="special">()</span></code> when |
| <code class="computeroutput"><span class="identifier">T</span></code> is an integral type, and |
| to <code class="computeroutput"><span class="special">-</span><span class="identifier">numeric_limits</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">max</span><span class="special">()</span></code> when |
| <code class="computeroutput"><span class="identifier">T</span></code> is a floating point type. |
| </p> |
| <div class="blockquote"><blockquote class="blockquote"> |
| <p> |
| </p> |
| <p> |
| <code class="computeroutput"><span class="identifier">highest</span><span class="special">()</span></code> |
| </p> |
| <p> |
| </p> |
| </blockquote></div> |
| <p> |
| Returns the maximum finite value, equivalent to <code class="computeroutput"><span class="identifier">numeric_limits</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">max</span><span class="special">()</span></code>. |
| </p> |
| <div class="blockquote"><blockquote class="blockquote"> |
| <p> |
| </p> |
| <p> |
| <code class="computeroutput"><span class="identifier">smallest</span><span class="special">()</span></code> |
| </p> |
| <p> |
| </p> |
| </blockquote></div> |
| <p> |
| Returns the smallest positive normalized value for floating point types with |
| denormalization, or returns 0 for integral types. |
| </p> |
| </div> |
| <div class="section" title="Examples"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="boost_numericconversion.bounds___traits_class.examples"></a><a class="link" href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.examples" title="Examples">Examples</a> |
| </h3></div></div></div> |
| <p> |
| The following example demonstrates the use of <code class="computeroutput"><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">bounds</span><span class="special"><></span></code> and the equivalent code using <code class="computeroutput"><span class="identifier">numeric_limits</span></code>: |
| </p> |
| <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> |
| |
| <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">numeric</span><span class="special">/</span><span class="identifier">conversion</span><span class="special">/</span><span class="identifier">bounds</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">limits</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| |
| <span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> <span class="special">{</span> |
| |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"numeric::bounds versus numeric_limits example.\n"</span><span class="special">;</span> |
| |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"The maximum value for float:\n"</span><span class="special">;</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">bounds</span><span class="special"><</span><span class="keyword">float</span><span class="special">>::</span><span class="identifier">highest</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"\n"</span><span class="special">;</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <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">float</span><span class="special">>::</span><span class="identifier">max</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"\n"</span><span class="special">;</span> |
| |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"The minimum value for float:\n"</span><span class="special">;</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">bounds</span><span class="special"><</span><span class="keyword">float</span><span class="special">>::</span><span class="identifier">lowest</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"\n"</span><span class="special">;</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <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">float</span><span class="special">>::</span><span class="identifier">max</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"\n"</span><span class="special">;</span> |
| |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"The smallest positive value for float:\n"</span><span class="special">;</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">bounds</span><span class="special"><</span><span class="keyword">float</span><span class="special">>::</span><span class="identifier">smallest</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"\n"</span><span class="special">;</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <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">float</span><span class="special">>::</span><span class="identifier">min</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"\n"</span><span class="special">;</span> |
| |
| <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> |
| <span class="special">}</span> |
| </pre> |
| </div> |
| </div> |
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| <td align="left"></td> |
| <td align="right"><div class="copyright-footer">Copyright © 2004 -2007 Fernando Luis Cacciola Carballal<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> |
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