ceph/src/boost/libs/metaparse/example/getting_started/7.hpp

   1 #ifndef BOOST_METAPARSE_GETTING_STARTED_7_HPP
   2 #define BOOST_METAPARSE_GETTING_STARTED_7_HPP
   3
   4 // Automatically generated header file
   5
   6 // Definitions before section 6.2
   7 #include "6_2.hpp"
   8
   9 // Definitions of section 6.2
  10 #include <boost/mpl/minus.hpp>
  11
  12 template <class L, char Op, class R> struct eval_binary_op;
  13
  14 template <class L, class R> struct eval_binary_op<L, '+', R> : boost::mpl::plus<L, R>::type {};
  15
  16 template <class L, class R> struct eval_binary_op<L, '-', R> : boost::mpl::minus<L, R>::type {};
  17
  18 // query:
  19 //    eval_binary_op<boost::mpl::int_<11>, '+', boost::mpl::int_<2>>::type
  20
  21 // query:
  22 //    eval_binary_op<boost::mpl::int_<13>, '-', boost::mpl::int_<2>>::type
  23
  24 template <class S, class Item>
  25  struct binary_op :
  26    eval_binary_op<
  27      S,
  28      boost::mpl::at_c<Item, 0>::type::value,
  29      typename boost::mpl::at_c<Item, 1>::type
  30    >
  31    {};
  32
  33 // query:
  34 //    binary_op<boost::mpl::int_<11>, boost::mpl::vector<boost::mpl::char_<'+'>, boost::mpl::int_<2>>>::type
  35
  36 using exp_parser13 =
  37  build_parser<
  38    foldl_start_with_parser<
  39      sequence<one_of<plus_token, minus_token>, int_token>,
  40      int_token,
  41      boost::mpl::quote2<binary_op>
  42    >
  43  >;
  44
  45 // query:
  46 //    exp_parser13::apply<BOOST_METAPARSE_STRING("1 + 2 - 3")>::type
  47
  48 #endif
  49