ceph/src/boost/libs/mpl/doc/refmanual/for-each.html

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  12 <td class="header-group page-location"><a href="../refmanual.html" class="navigation-link">Front Page</a> / <a href="./algorithms.html" class="navigation-link">Algorithms</a> / <a href="./runtime-algorithms.html" class="navigation-link">Runtime Algorithms</a> / <a href="./for-each.html" class="navigation-link">for_each</a></td>
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  14 <div class="section" id="for-each">
  15 <h1><a class="toc-backref" href="./runtime-algorithms.html#id1509">for_each</a></h1>
  16 <div class="section" id="id812">
  17 <h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3>
  18 <pre class="literal-block">
  19 template&lt;
  20       typename Sequence
  21     , typename F
  22     &gt;
  23 void <a href="./for-each.html" class="identifier">for_each</a>( F f );
  24
  25 template&lt;
  26       typename Sequence
  27     , typename TransformOp
  28     , typename F
  29     &gt;
  30 void <a href="./for-each.html" class="identifier">for_each</a>( F f );
  31 </pre>
  32 </div>
  33 <div class="section" id="id813">
  34 <h3><a class="subsection-title" href="#description" name="description">Description</a></h3>
  35 <p><tt class="literal"><span class="pre"><a href="./for-each.html" class="identifier">for_each</a></span></tt> is a family of overloaded function templates:</p>
  36 <ul class="simple">
  37 <li><tt class="literal"><span class="pre"><a href="./for-each.html" class="identifier">for_each</a>&lt;Sequence&gt;(</span> <span class="pre">f</span> <span class="pre">)</span></tt> applies the runtime function object
  38 <tt class="literal"><span class="pre">f</span></tt> to every element in the [<tt class="literal"><span class="pre"><a href="./begin.html" class="identifier">begin</a>&lt;Sequence&gt;::type</span></tt>, <tt class="literal"><span class="pre"><a href="./end.html" class="identifier">end</a>&lt;Sequence&gt;::type</span></tt>) range.</li>
  39 <li><tt class="literal"><span class="pre"><a href="./for-each.html" class="identifier">for_each</a>&lt;Sequence,TransformOp&gt;(</span> <span class="pre">f</span> <span class="pre">)</span></tt> applies the runtime function
  40 object <tt class="literal"><span class="pre">f</span></tt> to the result of the transformation <tt class="literal"><span class="pre">TransformOp</span></tt> of
  41 every element in the [<tt class="literal"><span class="pre"><a href="./begin.html" class="identifier">begin</a>&lt;Sequence&gt;::type</span></tt>, <tt class="literal"><span class="pre"><a href="./end.html" class="identifier">end</a>&lt;Sequence&gt;::type</span></tt>) range.</li>
  42 </ul>
  43 </div>
  44 <div class="section" id="id814">
  45 <h3><a class="subsection-title" href="#header" name="header">Header</a></h3>
  46 <pre class="literal-block">
  47 #include &lt;<a href="../../../../boost/mpl/for_each.hpp" class="header">boost/mpl/for_each.hpp</a>&gt;
  48 </pre>
  49 </div>
  50 <div class="section" id="id815">
  51 <h3><a class="subsection-title" href="#parameters" name="parameters">Parameters</a></h3>
  52 <table border="1" class="docutils table">
  53 <colgroup>
  54 <col width="21%" />
  55 <col width="39%" />
  56 <col width="39%" />
  57 </colgroup>
  58 <thead valign="bottom">
  59 <tr><th class="head">Parameter</th>
  60 <th class="head">Requirement</th>
  61 <th class="head">Description</th>
  62 </tr>
  63 </thead>
  64 <tbody valign="top">
  65 <tr><td><tt class="literal"><span class="pre">Sequence</span></tt></td>
  66 <td><a class="reference internal" href="./forward-sequence.html">Forward Sequence</a></td>
  67 <td>A sequence to iterate.</td>
  68 </tr>
  69 <tr><td><tt class="literal"><span class="pre">TransformOp</span></tt></td>
  70 <td><a class="reference internal" href="./lambda-expression.html">Lambda Expression</a></td>
  71 <td>A transformation.</td>
  72 </tr>
  73 <tr><td><tt class="literal"><span class="pre">f</span></tt></td>
  74 <td>An <a class="reference external" href="http://www.sgi.com/tech/stl/UnaryFunction.html" target="_top">unary function object</a></td>
  75 <td>A runtime operation to apply.</td>
  76 </tr>
  77 </tbody>
  78 </table>
  79 </div>
  80 <div class="section" id="id816">
  81 <h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3>
  82 <p>For any <a class="reference internal" href="./forward-sequence.html">Forward Sequence</a> <tt class="literal"><span class="pre">s</span></tt>, <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a> <tt class="literal"><span class="pre">op</span></tt> , and an
  83 <a class="reference external" href="http://www.sgi.com/tech/stl/UnaryFunction.html" target="_top">unary function object</a> <tt class="literal"><span class="pre">f</span></tt>:</p>
  84 <pre class="literal-block">
  85 <a href="./for-each.html" class="identifier">for_each</a>&lt;s&gt;( f );
  86 </pre>
  87 <table class="docutils field-list" frame="void" rules="none">
  88 <col class="field-name" />
  89 <col class="field-body" />
  90 <tbody valign="top">
  91 <tr class="field"><th class="field-name">Return type:</th><td class="field-body"><p class="first"><tt class="literal"><span class="pre">void</span></tt></p>
  92 </td>
  93 </tr>
  94 <tr class="field"><th class="field-name">Postcondition:</th><td class="field-body"><p class="first">Equivalent to</p>
  95 <pre class="literal-block">
  96 typedef <a href="./begin.html" class="identifier">begin</a>&lt;Sequence&gt;::type i<sub>1</sub>;
  97 <a class="reference external" href="http://www.boost.org/libs/utility/value_init.htm" target="_top">value_initialized</a>&lt; <a href="./deref.html" class="identifier">deref</a>&lt;i<sub>1</sub>&gt;::type &gt; x<sub>1</sub>;
  98 f(boost::get(x<sub>1</sub>));
  99
 100 typedef <a href="./next.html" class="identifier">next</a>&lt;i<sub>1</sub>&gt;::type i<sub>2</sub>;
 101 <a class="reference external" href="http://www.boost.org/libs/utility/value_init.htm" target="_top">value_initialized</a>&lt; <a href="./deref.html" class="identifier">deref</a>&lt;i<sub>2</sub>&gt;::type &gt; x<sub>2</sub>;
 102 f(boost::get(x<sub>2</sub>));
 103 <em>...</em>
 104 <a class="reference external" href="http://www.boost.org/libs/utility/value_init.htm" target="_top">value_initialized</a>&lt; <a href="./deref.html" class="identifier">deref</a>&lt;i<sub>n</sub>&gt;::type &gt; x<sub>n</sub>;
 105 f(boost::get(x<sub>n</sub>));
 106 typedef <a href="./next.html" class="identifier">next</a>&lt;i<sub>n</sub>&gt;::type last;
 107 </pre>
 108 <p class="last">where <tt class="literal"><span class="pre">n</span> <span class="pre">==</span> <span class="pre"><a href="./size.html" class="identifier">size</a>&lt;s&gt;::value</span></tt> and <tt class="literal"><span class="pre">last</span></tt> is identical to
 109 <tt class="literal"><span class="pre"><a href="./end.html" class="identifier">end</a>&lt;s&gt;::type</span></tt>; no effect if <tt class="literal"><span class="pre"><a href="./empty.html" class="identifier">empty</a>&lt;s&gt;::value</span> <span class="pre">==</span> <span class="pre">true</span></tt>.</p>
 110 </td>
 111 </tr>
 112 </tbody>
 113 </table>
 114 <pre class="literal-block">
 115 <a href="./for-each.html" class="identifier">for_each</a>&lt;s,op&gt;( f );
 116 </pre>
 117 <table class="docutils field-list" frame="void" rules="none">
 118 <col class="field-name" />
 119 <col class="field-body" />
 120 <tbody valign="top">
 121 <tr class="field"><th class="field-name">Return type:</th><td class="field-body"><p class="first"><tt class="literal"><span class="pre">void</span></tt></p>
 122 </td>
 123 </tr>
 124 <tr class="field"><th class="field-name">Postcondition:</th><td class="field-body"><p class="first">Equivalent to</p>
 125 <pre class="last literal-block">
 126 <a href="./for-each.html" class="identifier">for_each</a>&lt; <a href="./transform-view.html" class="identifier">transform_view</a>&lt;s,op&gt; &gt;( f );
 127 </pre>
 128 </td>
 129 </tr>
 130 </tbody>
 131 </table>
 132 </div>
 133 <div class="section" id="id817">
 134 <h3><a class="subsection-title" href="#complexity" name="complexity">Complexity</a></h3>
 135 <p>Linear. Exactly <tt class="literal"><span class="pre"><a href="./size.html" class="identifier">size</a>&lt;s&gt;::value</span></tt> applications of <tt class="literal"><span class="pre">op</span></tt> and <tt class="literal"><span class="pre">f</span></tt>.</p>
 136 </div>
 137 <div class="section" id="id818">
 138 <h3><a class="subsection-title" href="#example" name="example">Example</a></h3>
 139 <pre class="literal-block">
 140 struct value_printer
 141 {
 142     template&lt; typename U &gt; void operator()(U x)
 143     {
 144         std::cout &lt;&lt; x &lt;&lt; '\n';
 145     }
 146 };
 147
 148 int main()
 149 {
 150     <a href="./for-each.html" class="identifier">for_each</a>&lt; <a href="./range-c.html" class="identifier">range_c</a>&lt;int,0,10&gt; &gt;( value_printer() );
 151 }
 152 </pre>
 153 </div>
 154 <div class="section" id="id819">
 155 <h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3>
 156 <p><a class="reference internal" href="./runtime-algorithms.html">Runtime Algorithms</a>, <a class="reference internal" href="./views.html">Views</a>, <a class="reference internal" href="./transform-view.html">transform_view</a></p>
 157 </div>
 158 </div>
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