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  5. <title>References</title>
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  9. <link rel="up" href="../primitives.html" title="Primitives">
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  10. <link rel="prev" href="values.html" title="Values">
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  11. <link rel="next" href="arguments.html" title="Arguments">
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  17. <a accesskey="p" href="values.html"><img src="../../../images/prev.png" alt="Prev"></a><a accesskey="u" href="../primitives.html"><img src="../../../images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../images/home.png" alt="Home"></a><a accesskey="n" href="arguments.html"><img src="../../../images/next.png" alt="Next"></a>
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  19. <div class="section">
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  20. <div class="titlepage"><div><div><h4 class="title">
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  21. <a name="phoenix.starter_kit.primitives.references"></a><a class="link" href="references.html" title="References">References</a>
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  22. </h4></div></div></div>
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  23. <p>
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  24.           References are functions. They hold a reference to a value stored somewhere.
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  25.           For example, given:
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  26.         </p>
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  27. <pre class="programlisting"><span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="number">3</span><span class="special">;</span>
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  28. <span class="keyword">char</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">s</span> <span class="special">=</span> <span class="string">"Hello World"</span><span class="special">;</span>
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  29. </pre>
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  30. <p>
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  31.           we create <code class="computeroutput"><span class="identifier">references</span></code> to
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  32.           <code class="computeroutput"><span class="identifier">i</span></code> and <code class="computeroutput"><span class="identifier">s</span></code>
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  33.           this way:
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  34.         </p>
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  35. <pre class="programlisting"><span class="identifier">ref</span><span class="special">(</span><span class="identifier">i</span><span class="special">)</span>
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  36. <span class="identifier">ref</span><span class="special">(</span><span class="identifier">s</span><span class="special">)</span>
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  37. </pre>
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  38. <p>
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  39.           Like <code class="computeroutput"><span class="identifier">val</span></code>, the expressions
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  40.           above evaluates to a nullary function; the first one returning an <code class="computeroutput"><span class="keyword">int</span><span class="special">&amp;</span></code>,
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  41.           and the second one returning a <code class="computeroutput"><span class="keyword">char</span>
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  42.           <span class="keyword">const</span><span class="special">*&amp;</span></code>.
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  43.         </p>
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  44. <p>
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  45.           (See <a href="../../../../../example/references.cpp" target="_top">references.cpp</a>)
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  46.         </p>
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  48. <div class="titlepage"></div>
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  49. <p>
    50. 

  50.           <span class="inlinemediaobject"><img src="../../../images/tip.png" alt="tip"></span> Learn more about references <a class="link" href="../../modules/core/references.html" title="References">here.</a>
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  51.         </p>
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  52. </div>
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  53. </div>
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  54. <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
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  55. <td align="left"></td>
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  56. <td align="right"><div class="copyright-footer">Copyright &#169; 2002-2005, 2010 Joel de Guzman, Dan Marsden, Thomas Heller<p>
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  57.         Distributed under the Boost Software License, Version 1.0. (See accompanying
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  58.         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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  59.       </p>
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