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- <title>safe_signed_range<MIN, MAX, PP, EP> and safe_unsigned_range<MIN, MAX, PP, EP></title>
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- <td><h2>Safe Numerics</h2></td>
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- <a name="safe_numerics.safe_range"></a>safe_signed_range<MIN, MAX, PP, EP> and
- safe_unsigned_range<MIN, MAX, PP, EP></h3></div></div></div>
- <div class="toc"><dl class="toc">
- <dt><span class="section"><a href="safe_range.html#idm130203244016">Description</a></span></dt>
- <dt><span class="section"><a href="safe_range.html#idm130203241136">Notation</a></span></dt>
- <dt><span class="section"><a href="safe_range.html#idm130203233776">Associated Types</a></span></dt>
- <dt><span class="section"><a href="safe_range.html#idm130203226688">Template Parameters</a></span></dt>
- <dt><span class="section"><a href="safe_range.html#idm130203205424">Model of</a></span></dt>
- <dt><span class="section"><a href="safe_range.html#idm130203186512">Valid Expressions</a></span></dt>
- <dt><span class="section"><a href="safe_range.html#idm130203184224">Example of use</a></span></dt>
- <dt><span class="section"><a href="safe_range.html#idm130203099968">Header</a></span></dt>
- </dl></div>
- <div class="section">
- <div class="titlepage"><div><div><h4 class="title">
- <a name="idm130203244016"></a>Description</h4></div></div></div>
- <p>This type holds a signed or unsigned integer in the closed range
- [MIN, MAX]. A <code class="computeroutput">safe_signed_range<MIN, MAX, PP, EP></code> or
- <code class="computeroutput">safe_unsigned_range<MIN, MAX, PP, EP></code> can be used
- anywhere an arithmetic type is permitted. Any expression which uses either
- of these types is guaranteed to return an arithmetically correct value or
- to trap in some way.</p>
- </div>
- <div class="section">
- <div class="titlepage"><div><div><h4 class="title">
- <a name="idm130203241136"></a>Notation</h4></div></div></div>
- <div class="informaltable"><table class="table">
- <colgroup>
- <col align="left">
- <col align="left">
- </colgroup>
- <thead><tr>
- <th align="left">Symbol</th>
- <th align="left">Description</th>
- </tr></thead>
- <tbody><tr>
- <td align="left"><code class="computeroutput">MIN, MAX</code></td>
- <td align="left">Minimum and maximum values that the range can
- represent.</td>
- </tr></tbody>
- </table></div>
- </div>
- <div class="section">
- <div class="titlepage"><div><div><h4 class="title">
- <a name="idm130203233776"></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">PP</code></td>
- <td align="left">Promotion Policy. A type which specifies the result type of
- an expression using safe types.</td>
- </tr>
- <tr>
- <td align="left"><code class="computeroutput">EP</code></td>
- <td align="left">Exception Policy. A type containing members which are
- called when a correct result cannot be returned</td>
- </tr>
- </tbody>
- </table></div>
- </div>
- <div class="section">
- <div class="titlepage"><div><div><h4 class="title">
- <a name="idm130203226688"></a>Template Parameters</h4></div></div></div>
- <div class="informaltable"><table class="table">
- <colgroup>
- <col align="left">
- <col align="left">
- <col align="left">
- </colgroup>
- <thead><tr>
- <th align="left">Parameter</th>
- <th align="left">Requirements</th>
- <th align="left">Description</th>
- </tr></thead>
- <tbody>
- <tr>
- <td align="left"><code class="computeroutput">MIN</code></td>
- <td align="left">must be a non-negative literal</td>
- <td align="left">The minimum non-negative integer value that this type may
- hold</td>
- </tr>
- <tr>
- <td align="left"><code class="computeroutput">MAX</code></td>
- <td align="left">must be a non-negative literal</td>
- <td align="left">The maximum non-negative integer value that this type may
- hold</td>
- </tr>
- <tr>
- <td align="left"> </td>
- <td align="left">MIN <= MAX</td>
- <td align="left">must be a valid closed range</td>
- </tr>
- <tr>
- <td align="left"><code class="computeroutput">PP</code></td>
- <td align="left"><a class="link" href="numeric.html" title="Numeric<T>">PromotionPolicy<PP></a></td>
- <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>
- </tr>
- <tr>
- <td align="left"><code class="computeroutput">EP</code></td>
- <td align="left"><a class="link" href="numeric.html" title="Numeric<T>">Exception
- Policy<EP></a></td>
- <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>
- </tr>
- </tbody>
- </table></div>
- </div>
- <div class="section">
- <div class="titlepage"><div><div><h4 class="title">
- <a name="idm130203205424"></a>Model of</h4></div></div></div>
- <p><a class="link" href="numeric.html" title="Numeric<T>">Integer</a></p>
- <p><a class="link" href="safe_numeric_concept.html" title="SafeNumeric<T>">SafeNumeric</a></p>
- </div>
- <div class="section">
- <div class="titlepage"><div><div><h4 class="title">
- <a name="idm130203186512"></a>Valid Expressions</h4></div></div></div>
- <p>Implements all expressions and only those expressions defined by the
- <a class="link" href="safe_numeric_concept.html" title="SafeNumeric<T>">SafeNumeric</a> type
- requirements. Thus, the result type of such an expression will be another
- safe type. The actual type of the result of such an expression will depend
- upon the specific promotion policy template parameter.</p>
- </div>
- <div class="section">
- <div class="titlepage"><div><div><h4 class="title">
- <a name="idm130203184224"></a>Example of use</h4></div></div></div>
- <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">type_traits</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">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>
- <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>
- <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>
- <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>
- <span class="keyword">void</span> <span class="identifier">f</span><span class="special">(</span><span class="special">)</span><span class="special">{</span>
- <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>
- <span class="comment">// since the range is included in [0,255], the underlying type of i </span>
- <span class="comment">// will be an unsigned char.</span>
- <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>
- <span class="identifier">i</span> <span class="special">=</span> <span class="number">9</span><span class="special">;</span> <span class="comment">// ok</span>
- <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>
- <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>
- <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>
- <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>
- <span class="comment">// if either or both types are safe types, the result is a safe type</span>
- <span class="comment">// determined by promotion policy. In this instance</span>
- <span class="comment">// the range of i is [7, 24] and the range of j is [0,255].</span>
- <span class="comment">// so the type of k will be a safe type with a range of [7,279]</span>
- <span class="identifier">static_assert</span><span class="special">(</span>
- <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>
- <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>
- <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>
- <span class="string">"k is a safe range of [7,279]"</span>
- <span class="special">)</span><span class="special">;</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="special">{</span><span class="special">}</span>
- </pre>
- </div>
- <div class="section">
- <div class="titlepage"><div><div><h4 class="title">
- <a name="idm130203099968"></a>Header</h4></div></div></div>
- <p><code class="filename"><a href="../../include/safe_range.hpp" target="_top">#include
- <boost/numeric/safe_numerics/safe_range.hpp></a></code></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 © 2012-2018 Robert Ramey<p><a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">Subject to Boost
- Software License</a></p>
- </div></td>
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