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26 | <div class="titlepage"><div><div><h4 class="title"> | |
27 | <a name="phoenix.modules.statement.switch__statement"></a><a class="link" href="switch__statement.html" title="switch_ Statement">switch_ | |
28 | Statement</a> | |
29 | </h4></div></div></div> | |
30 | <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">phoenix</span><span class="special">/</span><span class="identifier">statement</span><span class="special">/</span><span class="keyword">switch</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> | |
31 | </pre> | |
32 | <p> | |
33 | The syntax is: | |
34 | </p> | |
35 | <pre class="programlisting"><span class="identifier">switch_</span><span class="special">(</span><span class="identifier">integral_expression</span><span class="special">)</span> | |
36 | <span class="special">[</span> | |
37 | <span class="identifier">case_</span><span class="special"><</span><span class="identifier">integral_value</span><span class="special">>(</span><span class="identifier">sequenced_statements</span><span class="special">),</span> | |
38 | <span class="special">...</span> | |
39 | <span class="identifier">default_</span><span class="special"><</span><span class="identifier">integral_value</span><span class="special">>(</span><span class="identifier">sequenced_statements</span><span class="special">)</span> | |
40 | <span class="special">]</span> | |
41 | </pre> | |
42 | <p> | |
43 | A comma separated list of cases, and an optional default can be provided. | |
44 | Note unlike a normal switch statement, cases do not fall through. | |
45 | </p> | |
46 | <p> | |
47 | Example: This code prints out <code class="computeroutput"><span class="string">"one"</span></code>, | |
48 | <code class="computeroutput"><span class="string">"two"</span></code> or <code class="computeroutput"><span class="string">"other value"</span></code> depending on the | |
49 | element's actual value: | |
50 | </p> | |
51 | <pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">for_each</span><span class="special">(</span><span class="identifier">c</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">c</span><span class="special">.</span><span class="identifier">end</span><span class="special">(),</span> | |
52 | <span class="identifier">switch_</span><span class="special">(</span><span class="identifier">arg1</span><span class="special">)</span> | |
53 | <span class="special">[</span> | |
54 | <span class="identifier">case_</span><span class="special"><</span><span class="number">1</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">val</span><span class="special">(</span><span class="string">"one"</span><span class="special">)</span> <span class="special"><<</span> <span class="char">'\n'</span><span class="special">),</span> | |
55 | <span class="identifier">case_</span><span class="special"><</span><span class="number">2</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">val</span><span class="special">(</span><span class="string">"two"</span><span class="special">)</span> <span class="special"><<</span> <span class="char">'\n'</span><span class="special">),</span> | |
56 | <span class="identifier">default_</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">val</span><span class="special">(</span><span class="string">"other value"</span><span class="special">)</span> <span class="special"><<</span> <span class="char">'\n'</span><span class="special">)</span> | |
57 | <span class="special">]</span> | |
58 | <span class="special">);</span> | |
59 | </pre> | |
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63 | <td align="right"><div class="copyright-footer">Copyright © 2002-2005, 2010, 2014, 2015 Joel de Guzman, Dan Marsden, Thomas | |
64 | Heller, John Fletcher<p> | |
65 | Distributed under the Boost Software License, Version 1.0. (See accompanying | |
66 | 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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