ceph/src/boost/libs/proto/doc/reference/concepts/Transform.xml

   1 <?xml version="1.0" ?>
   2 <!--
   3   Copyright 2008 Eric Niebler
   4
   5   Distributed under the Boost
   6   Software License, Version 1.0. (See accompanying
   7   file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   8   -->
   9 <concept name="Transform" category="utility">
  10   <param name="Tn" role="transform-type" />
  11   <param name="Expr" role="expression-type" />
  12   <param name="State" role="state-type" />
  13   <param name="Data" role="data-type" />
  14
  15   <models-sentence>
  16     The type <arg num="1" /> must be a model of <self/>.
  17   </models-sentence>
  18
  19   <description>
  20     <para>
  21       A Transform is a PrimitiveTransform, a CallableTransform
  22       or an ObjectTransform.
  23     </para>
  24   </description>
  25
  26   <notation variables="expr">
  27     <sample-value>
  28       <type name="Expr" />
  29     </sample-value>
  30   </notation>
  31
  32   <notation variables="state">
  33     <sample-value>
  34       <type name="State" />
  35     </sample-value>
  36   </notation>
  37
  38   <notation variables="data">
  39     <sample-value>
  40       <type name="Data" />
  41     </sample-value>
  42   </notation>
  43
  44   <associated-type name="result_type">
  45     <get-member-type name="type">
  46       <apply-template name="boost::result_of">
  47         <type name="when&lt; _, Tn &gt;(Expr, State, Data)"/>
  48       </apply-template>
  49     </get-member-type>
  50     <description>
  51       <simpara>The result of applying the Transform.</simpara>
  52     </description>
  53   </associated-type>
  54
  55   <valid-expression name="Apply Transform">
  56     <apply-function name="when&lt; _, Tn &gt;()">
  57       <sample-value>
  58         <type name="Expr" />
  59       </sample-value>
  60       <sample-value>
  61         <type name="State" />
  62       </sample-value>
  63       <sample-value>
  64         <type name="Data" />
  65       </sample-value>
  66     </apply-function>
  67     <return-type>
  68       <require-same-type testable="yes">
  69         <type name="result_type"/>
  70       </require-same-type>
  71     </return-type>
  72     <semantics>Applies the transform.</semantics>
  73   </valid-expression>
  74
  75   <example-model>
  76     <type name="boost::proto::_child(boost::proto::_left)" />
  77   </example-model>
  78
  79 </concept>