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| <a name="boost_typetraits.examples.improved_min"></a><a class="link" href="improved_min.html" title="Improving std::min with common_type"> Improving std::min |
| with common_type</a> |
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| <p> |
| An improved <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">min</span></code> function could be written like this: |
| </p> |
| <pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">U</span><span class="special">></span> |
| <span class="keyword">typename</span> <a class="link" href="../reference/common_type.html" title="common_type">common_type</a><span class="special"><</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">U</span><span class="special">>::</span><span class="identifier">type</span> <span class="identifier">min</span><span class="special">(</span><span class="identifier">T</span> <span class="identifier">t</span><span class="special">,</span> <span class="identifier">T</span> <span class="identifier">u</span><span class="special">)</span> |
| <span class="special">{</span> |
| <span class="keyword">return</span> <span class="identifier">t</span> <span class="special"><</span> <span class="identifier">u</span> <span class="special">?</span> <span class="identifier">t</span> <span class="special">:</span> <span class="identifier">u</span><span class="special">;</span> |
| <span class="special">}</span> |
| </pre> |
| <p> |
| And now expressions such as: |
| </p> |
| <pre class="programlisting"><span class="identifier">min</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="number">2.0</span><span class="special">)</span> |
| </pre> |
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| will actually compile and return the correct type! |
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| <td align="right"><div class="copyright-footer">Copyright © 2000, 2006 Adobe Systems Inc, David Abrahams, |
| Steve Cleary, Beman Dawes, Aleksey Gurtovoy, Howard Hinnant, Jesse Jones, Mat |
| Marcus, Itay Maman, John Maddock, Alexander Nasonov, Thorsten Ottosen, Robert |
| Ramey and Jeremy Siek<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>) |
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