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26<div class="refentry"> 27<a name="boost.CV.constrained_value"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Class template constrained_value</span></h2> 30<p>boost::CV::constrained_value — A template to specify a constrained basic value type. </p> 31</div> 32<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 33<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../date_time/doxy.html#header.boost.date_time.constrained_value_hpp" title="Header <boost/date_time/constrained_value.hpp>">boost/date_time/constrained_value.hpp</a>> 34 35</span><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> value_policies<span class="special">></span> 36<span class="keyword">class</span> <a class="link" href="constrained_value.html" title="Class template constrained_value">constrained_value</a> <span class="special">{</span> 37<span class="keyword">public</span><span class="special">:</span> 38 <span class="comment">// types</span> 39 <span class="keyword">typedef</span> <span class="identifier">value_policies</span><span class="special">::</span><span class="identifier">value_type</span> <a name="boost.CV.constrained_value.value_type"></a><span class="identifier">value_type</span><span class="special">;</span> 40 41 <span class="comment">// <a class="link" href="constrained_value.html#boost.CV.constrained_valueconstruct-copy-destruct">construct/copy/destruct</a></span> 42 <a class="link" href="constrained_value.html#id-1_3_14_15_3_6_1_1_1_6-bb"><span class="identifier">constrained_value</span></a><span class="special">(</span><span class="identifier">value_type</span><span class="special">)</span><span class="special">;</span> 43 <span class="identifier">BOOST_CXX14_CONSTEXPR</span> <a class="link" href="constrained_value.html" title="Class template constrained_value">constrained_value</a> <span class="special">&</span> <a class="link" href="constrained_value.html#id-1_3_14_15_3_6_1_1_1_7-bb"><span class="keyword">operator</span><span class="special">=</span></a><span class="special">(</span><span class="identifier">value_type</span><span class="special">)</span><span class="special">;</span> 44 45 <span class="comment">// <a class="link" href="constrained_value.html#id-1_3_14_15_3_6_1_1_1_5-bb">public member functions</a></span> 46 <span class="identifier">BOOST_CXX14_CONSTEXPR</span> <a class="link" href="constrained_value.html#id-1_3_14_15_3_6_1_1_1_5_1-bb"><span class="keyword">operator</span> <span class="identifier">value_type</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span> 47 48 <span class="comment">// <a class="link" href="constrained_value.html#id-1_3_14_15_3_6_1_1_1_8-bb">public static functions</a></span> 49 <span class="keyword">static</span> <span class="identifier">BOOST_CONSTEXPR</span> <span class="identifier">value_type</span> <span class="identifier">max</span> <a class="link" href="constrained_value.html#id-1_3_14_15_3_6_1_1_1_8_1-bb"><span class="identifier">BOOST_PREVENT_MACRO_SUBSTITUTION</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 50 <span class="keyword">static</span> <span class="identifier">BOOST_CONSTEXPR</span> <span class="identifier">value_type</span> <span class="identifier">min</span> <a class="link" href="constrained_value.html#id-1_3_14_15_3_6_1_1_1_8_2-bb"><span class="identifier">BOOST_PREVENT_MACRO_SUBSTITUTION</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 51 52 <span class="comment">// <a class="link" href="constrained_value.html#id-1_3_14_15_3_6_1_1_1_9-bb">private member functions</a></span> 53 <span class="identifier">BOOST_CXX14_CONSTEXPR</span> <span class="keyword">void</span> <a class="link" href="constrained_value.html#id-1_3_14_15_3_6_1_1_1_9_1-bb"><span class="identifier">assign</span></a><span class="special">(</span><span class="identifier">value_type</span><span class="special">)</span><span class="special">;</span> 54<span class="special">}</span><span class="special">;</span></pre></div> 55<div class="refsect1"> 56<a name="id-1.3.14.15.3.6.3.4"></a><h2>Description</h2> 57<p>This template provides a quick way to generate an integer type with a constrained range. The type provides for the ability to specify the min, max, and and error handling policy.</p> 58<p><span class="bold"><strong>value policies</strong></span> A class that provides the range limits via the min and max functions as well as a function on_error that determines how errors are handled. A common strategy would be to assert or throw and exception. The on_error is passed both the current value and the new value that is in error. </p> 59<div class="refsect2"> 60<a name="id-1.3.14.15.3.6.3.4.4"></a><h3> 61<a name="boost.CV.constrained_valueconstruct-copy-destruct"></a><code class="computeroutput">constrained_value</code> 62 public 63 construct/copy/destruct</h3> 64<div class="orderedlist"><ol class="orderedlist" type="1"> 65<li class="listitem"><pre class="literallayout"><a name="id-1_3_14_15_3_6_1_1_1_6-bb"></a><span class="identifier">constrained_value</span><span class="special">(</span><span class="identifier">value_type</span> value<span class="special">)</span><span class="special">;</span></pre></li> 66<li class="listitem"><pre class="literallayout"><span class="identifier">BOOST_CXX14_CONSTEXPR</span> <a class="link" href="constrained_value.html" title="Class template constrained_value">constrained_value</a> <span class="special">&</span> <a name="id-1_3_14_15_3_6_1_1_1_7-bb"></a><span class="keyword">operator</span><span class="special">=</span><span class="special">(</span><span class="identifier">value_type</span> v<span class="special">)</span><span class="special">;</span></pre></li> 67</ol></div> 68</div> 69<div class="refsect2"> 70<a name="id-1.3.14.15.3.6.3.4.5"></a><h3> 71<a name="id-1_3_14_15_3_6_1_1_1_5-bb"></a><code class="computeroutput">constrained_value</code> public member functions</h3> 72<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"> 73<pre class="literallayout"><span class="identifier">BOOST_CXX14_CONSTEXPR</span> <a name="id-1_3_14_15_3_6_1_1_1_5_1-bb"></a><span class="keyword">operator</span> <span class="identifier">value_type</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>Coerce into the representation type. </li></ol></div> 74</div> 75<div class="refsect2"> 76<a name="id-1.3.14.15.3.6.3.4.6"></a><h3> 77<a name="id-1_3_14_15_3_6_1_1_1_8-bb"></a><code class="computeroutput">constrained_value</code> public static functions</h3> 78<div class="orderedlist"><ol class="orderedlist" type="1"> 79<li class="listitem"> 80<pre class="literallayout"><span class="keyword">static</span> <span class="identifier">BOOST_CONSTEXPR</span> <span class="identifier">value_type</span> <span class="identifier">max</span> <a name="id-1_3_14_15_3_6_1_1_1_8_1-bb"></a><span class="identifier">BOOST_PREVENT_MACRO_SUBSTITUTION</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>Return the max allowed value (traits method) </li> 81<li class="listitem"> 82<pre class="literallayout"><span class="keyword">static</span> <span class="identifier">BOOST_CONSTEXPR</span> <span class="identifier">value_type</span> <span class="identifier">min</span> <a name="id-1_3_14_15_3_6_1_1_1_8_2-bb"></a><span class="identifier">BOOST_PREVENT_MACRO_SUBSTITUTION</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>Return the min allowed value (traits method) </li> 83</ol></div> 84</div> 85<div class="refsect2"> 86<a name="id-1.3.14.15.3.6.3.4.7"></a><h3> 87<a name="id-1_3_14_15_3_6_1_1_1_9-bb"></a><code class="computeroutput">constrained_value</code> private member functions</h3> 88<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><pre class="literallayout"><span class="identifier">BOOST_CXX14_CONSTEXPR</span> <span class="keyword">void</span> <a name="id-1_3_14_15_3_6_1_1_1_9_1-bb"></a><span class="identifier">assign</span><span class="special">(</span><span class="identifier">value_type</span> value<span class="special">)</span><span class="special">;</span></pre></li></ol></div> 89</div> 90</div> 91</div> 92<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 93<td align="left"></td> 94<td align="right"><div class="copyright-footer">Copyright © 2001-2005 CrystalClear Software, Inc<p>Subject to the Boost Software License, Version 1.0. (See accompanying file 95 <code class="filename">LICENSE_1_0.txt</code> 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> 96</div></td> 97</tr></table> 98<hr> 99<div class="spirit-nav"> 100<a accesskey="p" href="../date_time/c_time.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../date_time/doxy.html#header.boost.date_time.constrained_value_hpp"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="simple_exception_policy.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 101</div> 102</body> 103</html> 104
