ceph/src/boost/libs/metaparse/example/getting_started/5_2_2.hpp

   1 #ifndef BOOST_METAPARSE_GETTING_STARTED_5_2_2_HPP
   2 #define BOOST_METAPARSE_GETTING_STARTED_5_2_2_HPP
   3
   4 // Automatically generated header file
   5
   6 // Definitions before section 5.2.1
   7 #include "5_2_1.hpp"
   8
   9 // Definitions of section 5.2.1
  10 #include <boost/mpl/fold.hpp>
  11
  12 using vector_of_numbers =
  13  boost::mpl::vector<
  14    boost::mpl::int_<2>,
  15    boost::mpl::int_<5>,
  16    boost::mpl::int_<6>
  17  >;
  18
  19 template <class Vector>
  20  struct sum_vector :
  21     boost::mpl::fold<
  22       Vector,
  23       boost::mpl::int_<0>,
  24       boost::mpl::lambda<
  25         boost::mpl::plus<boost::mpl::_1, boost::mpl::_2>
  26       >::type
  27     >
  28   {};
  29
  30 // query:
  31 //    sum_vector<vector_of_numbers>::type
  32
  33 template <class Sum, class Item>
  34    struct sum_items :
  35      boost::mpl::plus<
  36        Sum,
  37        typename boost::mpl::at_c<Item, 1>::type
  38      >
  39  {};
  40
  41 // query:
  42 //   sum_items<
  43 //      mpl_::integral_c<int, 1>,
  44 //      boost::mpl::vector<mpl_::char_<'+'>, mpl_::integral_c<int, 2>>
  45 //    >::type
  46
  47 // query:
  48 //    boost::mpl::at_c<temp_result, 1>::type
  49
  50 // query:
  51 //   boost::mpl::fold<
  52 //      boost::mpl::at_c<temp_result, 1>::type, /* The vector to summarise */
  53 //      boost::mpl::int_<0>, /* The value to start the sum from */
  54 //      boost::mpl::quote2<sum_items> /* The function to call in each iteration */
  55 //    >::type
  56
  57 #endif
  58