ceph/src/boost/libs/phoenix/doc/html/phoenix/modules/statement/block_statement.html

   1 <html>
   2 <head>
   3 <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
   4 <title>Block Statement</title>
   5 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
   6 <meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
   7 <link rel="home" href="../../../index.html" title="Chapter&#160;1.&#160;Phoenix 3.2.0">
   8 <link rel="up" href="../statement.html" title="Statement">
   9 <link rel="prev" href="../statement.html" title="Statement">
  10 <link rel="next" href="if__statement.html" title="if_ Statement">
  11 </head>
  12 <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
  13 <table cellpadding="2" width="100%"><tr>
  14 <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td>
  15 <td align="center"><a href="../../../../../../../index.html">Home</a></td>
  16 <td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td>
  17 <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
  18 <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
  19 <td align="center"><a href="../../../../../../../more/index.htm">More</a></td>
  20 </tr></table>
  21 <hr>
  22 <div class="spirit-nav">
  23 <a accesskey="p" href="../statement.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../statement.html"><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="if__statement.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
  24 </div>
  25 <div class="section">
  26 <div class="titlepage"><div><div><h4 class="title">
  27 <a name="phoenix.modules.statement.block_statement"></a><a class="link" href="block_statement.html" title="Block Statement">Block Statement</a>
  28 </h4></div></div></div>
  29 <p>
  30           Syntax:
  31         </p>
  32 <pre class="programlisting"><span class="identifier">statement</span><span class="special">,</span>
  33 <span class="identifier">statement</span><span class="special">,</span>
  34 <span class="special">....</span>
  35 <span class="identifier">statement</span>
  36 </pre>
  37 <p>
  38           Basically, these are comma separated statements. Take note that unlike
  39           the C/C++ semicolon, the comma is a separator put <span class="bold"><strong>in-between</strong></span>
  40           statements. This is like Pascal's semicolon separator, rather than C/C++'s
  41           semicolon terminator. For example:
  42         </p>
  43 <pre class="programlisting"><span class="identifier">statement</span><span class="special">,</span>
  44 <span class="identifier">statement</span><span class="special">,</span>
  45 <span class="identifier">statement</span><span class="special">,</span> <span class="comment">// ERROR!</span>
  46 </pre>
  47 <p>
  48           Is an error. The last statement should not have a comma. Block statements
  49           can be grouped using the parentheses. Again, the last statement in a group
  50           should not have a trailing comma.
  51         </p>
  52 <pre class="programlisting"><span class="identifier">statement</span><span class="special">,</span>
  53 <span class="identifier">statement</span><span class="special">,</span>
  54 <span class="special">(</span>
  55     <span class="identifier">statement</span><span class="special">,</span>
  56     <span class="identifier">statement</span>
  57 <span class="special">),</span>
  58 <span class="identifier">statement</span>
  59 </pre>
  60 <p>
  61           Outside the square brackets, block statements should be grouped. For example:
  62         </p>
  63 <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>
  64     <span class="special">(</span>
  65         <span class="identifier">do_this</span><span class="special">(</span><span class="identifier">arg1</span><span class="special">),</span>
  66         <span class="identifier">do_that</span><span class="special">(</span><span class="identifier">arg1</span><span class="special">)</span>
  67     <span class="special">)</span>
  68 <span class="special">);</span>
  69 </pre>
  70 <p>
  71           Wrapping a comma operator chain around a parentheses pair blocks the interpretation
  72           as an argument separator. The reason for the exception for the square bracket
  73           operator is that the operator always takes exactly one argument, so it
  74           "transforms" any attempt at multiple arguments with a comma operator
  75           chain (and spits out an error for zero arguments).
  76         </p>
  77 </div>
  78 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
  79 <td align="left"></td>
  80 <td align="right"><div class="copyright-footer">Copyright &#169; 2002-2005, 2010, 2014, 2015 Joel de Guzman, Dan Marsden, Thomas
  81       Heller, John Fletcher<p>
  82         Distributed under the Boost Software License, Version 1.0. (See accompanying
  83         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>)
  84       </p>
  85 </div></td>
  86 </tr></table>
  87 <hr>
  88 <div class="spirit-nav">
  89 <a accesskey="p" href="../statement.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../statement.html"><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="if__statement.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
  90 </div>
  91 </body>
  92 </html>