ceph/src/boost/libs/wave/include/boost/wave/util/transform_iterator.hpp

   1 /*=============================================================================
   2     Boost.Wave: A Standard compliant C++ preprocessor library
   3
   4     http://www.boost.org/
   5
   6     Copyright (c) 2001-2012 Hartmut Kaiser. Distributed under the Boost
   7     Software License, Version 1.0. (See accompanying file
   8     LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9 =============================================================================*/
  10
  11 #if !defined(TRANSFORM_ITERATOR_HPP_D492C659_88C7_4258_8C42_192F9AE80EC0_INCLUDED)
  12 #define TRANSFORM_ITERATOR_HPP_D492C659_88C7_4258_8C42_192F9AE80EC0_INCLUDED
  13
  14 #include <boost/config.hpp>
  15 #include <boost/iterator_adaptors.hpp>
  16 #include <boost/iterator/transform_iterator.hpp>
  17
  18 #include <boost/assert.hpp>
  19
  20 // this must occur after all of the includes and before any code appears
  21 #ifdef BOOST_HAS_ABI_HEADERS
  22 #include BOOST_ABI_PREFIX
  23 #endif
  24
  25 ///////////////////////////////////////////////////////////////////////////////
  26 namespace boost {
  27 namespace wave {
  28 namespace impl {
  29
  30 ///////////////////////////////////////////////////////////////////////////////
  31 //
  32 //  The new Boost.Iterator library already conatins a transform_iterator usable
  33 //  for our needs. The code below wraps this up.
  34 //
  35 ///////////////////////////////////////////////////////////////////////////////
  36     template <class AdaptableUnaryFunctionT, class IteratorT>
  37     class ref_transform_iterator_generator
  38     {
  39         typedef typename AdaptableUnaryFunctionT::result_type   return_type;
  40         typedef typename AdaptableUnaryFunctionT::argument_type argument_type;
  41
  42     public:
  43         typedef boost::transform_iterator<
  44                 return_type (*)(argument_type), IteratorT, return_type>
  45             type;
  46     };
  47
  48     template <class AdaptableUnaryFunctionT, class IteratorT>
  49     inline
  50     typename ref_transform_iterator_generator<
  51         AdaptableUnaryFunctionT, IteratorT>::type
  52     make_ref_transform_iterator(
  53         IteratorT base, AdaptableUnaryFunctionT const &f)
  54     {
  55         typedef typename ref_transform_iterator_generator<
  56                 AdaptableUnaryFunctionT, IteratorT>::type
  57             iterator_type;
  58         return iterator_type(base, f.transform);
  59     }
  60
  61     //  Retrieve the token value given a parse node
  62     //  This is used in conjunction with the ref_transform_iterator above, to
  63     //  get the token values while iterating directly over the parse tree.
  64     template <typename TokenT, typename ParseTreeNodeT>
  65     struct get_token_value {
  66
  67         typedef TokenT const &result_type;
  68         typedef ParseTreeNodeT const &argument_type;
  69
  70         static result_type
  71         transform (argument_type node)
  72         {
  73             BOOST_ASSERT(1 == std::distance(node.value.begin(),
  74                 node.value.end()));
  75             return *node.value.begin();
  76         }
  77     };
  78
  79 ///////////////////////////////////////////////////////////////////////////////
  80 }   // namespace impl
  81 }   // namespace wave
  82 }   // namespace boost
  83
  84 // the suffix header occurs after all of the code
  85 #ifdef BOOST_HAS_ABI_HEADERS
  86 #include BOOST_ABI_SUFFIX
  87 #endif
  88
  89 #endif // !defined(TRANSFORM_ITERATOR_HPP_D492C659_88C7_4258_8C42_192F9AE80EC0_INCLUDED)