deps/boost_1_63_0/boost/fusion/sequence/io/detail/in.hpp

   1 /*=============================================================================
   2     Copyright (c) 1999-2003 Jaakko Jarvi
   3     Copyright (c) 1999-2003 Jeremiah Willcock
   4     Copyright (c) 2001-2011 Joel de Guzman
   5
   6     Distributed under the Boost 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 #if !defined(FUSION_IN_05052005_0121)
  10 #define FUSION_IN_05052005_0121
  11
  12 #include <boost/fusion/support/config.hpp>
  13 #include <istream>
  14 #include <boost/fusion/sequence/io/detail/manip.hpp>
  15
  16 #include <boost/mpl/bool.hpp>
  17 #include <boost/fusion/sequence/intrinsic/begin.hpp>
  18 #include <boost/fusion/sequence/intrinsic/end.hpp>
  19 #include <boost/fusion/iterator/deref.hpp>
  20 #include <boost/fusion/iterator/next.hpp>
  21 #include <boost/fusion/iterator/equal_to.hpp>
  22
  23 namespace boost { namespace fusion { namespace detail
  24 {
  25     template <typename Tag>
  26     struct delimiter_in
  27     {
  28         // read a delimiter
  29         template <typename IS>
  30         static void
  31         read(IS& is, char const* delim, mpl::false_ = mpl::false_())
  32         {
  33             detail::string_ios_manip<Tag, IS> manip(is);
  34             manip.read(delim);
  35         }
  36
  37         template <typename IS>
  38         static void
  39         read(IS&, char const*, mpl::true_)
  40         {
  41         }
  42     };
  43
  44     struct read_sequence_loop
  45     {
  46         template <typename IS, typename First, typename Last>
  47         static void
  48         call(IS&, First const&, Last const&, mpl::true_)
  49         {
  50         }
  51
  52         template <typename IS, typename First, typename Last>
  53         static void
  54         call(IS& is, First const& first, Last const& last, mpl::false_)
  55         {
  56             result_of::equal_to<
  57                 typename result_of::next<First>::type
  58               , Last
  59             >
  60             is_last;
  61
  62             is >> *first;
  63             delimiter_in<tuple_delimiter_tag>::read(is, " ", is_last);
  64             call(is, fusion::next(first), last, is_last);
  65         }
  66
  67         template <typename IS, typename First, typename Last>
  68         static void
  69         call(IS& is, First const& first, Last const& last)
  70         {
  71             result_of::equal_to<First, Last> eq;
  72             call(is, first, last, eq);
  73         }
  74     };
  75
  76     template <typename IS, typename Sequence>
  77     inline void
  78     read_sequence(IS& is, Sequence& seq)
  79     {
  80         delimiter_in<tuple_open_tag>::read(is, "(");
  81         read_sequence_loop::call(is, fusion::begin(seq), fusion::end(seq));
  82         delimiter_in<tuple_close_tag>::read(is, ")");
  83     }
  84 }}}
  85
  86 #endif