boost/boost/iostreams/input_sequence.hpp

   1 // (C) Copyright Jonathan Turkanis 2003.
   2 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   3 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
   4
   5 // See http://www.boost.org/libs/iostreams for documentation.
   6
   7 #ifndef BOOST_IOSTREAMS_INPUT_SEQUENCE_HPP_INCLUDED
   8 #define BOOST_IOSTREAMS_INPUT_SEQUENCE_HPP_INCLUDED
   9
  10 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
  11 # pragma once
  12 #endif
  13
  14 #include <utility>           // pair.
  15 #include <boost/config.hpp>  // DEDUCED_TYPENAME, MSVC.
  16 #include <boost/detail/workaround.hpp>
  17 #include <boost/iostreams/detail/wrap_unwrap.hpp>
  18 #include <boost/iostreams/traits.hpp>
  19 #include <boost/mpl/if.hpp>
  20
  21 // Must come last.
  22 #include <boost/iostreams/detail/config/disable_warnings.hpp>
  23
  24 namespace boost { namespace iostreams {
  25
  26 namespace detail {
  27
  28 template<typename T>
  29 struct input_sequence_impl;
  30
  31 } // End namespace detail.
  32
  33 template<typename T>
  34 inline std::pair<
  35     BOOST_DEDUCED_TYPENAME char_type_of<T>::type*,
  36     BOOST_DEDUCED_TYPENAME char_type_of<T>::type*
  37 >
  38 input_sequence(T& t)
  39 { return detail::input_sequence_impl<T>::input_sequence(t); }
  40
  41 namespace detail {
  42
  43 //------------------Definition of direct_impl-------------------------------//
  44
  45 template<typename T>
  46 struct input_sequence_impl
  47     : mpl::if_<
  48           detail::is_custom<T>,
  49           operations<T>,
  50           input_sequence_impl<direct_tag>
  51       >::type
  52     { };
  53
  54 template<>
  55 struct input_sequence_impl<direct_tag> {
  56     template<typename U>
  57     static std::pair<
  58         BOOST_DEDUCED_TYPENAME char_type_of<U>::type*,
  59         BOOST_DEDUCED_TYPENAME char_type_of<U>::type*
  60     >
  61     input_sequence(U& u) { return u.input_sequence(); }
  62 };
  63
  64 } // End namespace detail.
  65
  66 } } // End namespaces iostreams, boost.
  67
  68 #include <boost/iostreams/detail/config/enable_warnings.hpp>
  69
  70 #endif // #ifndef BOOST_IOSTREAMS_INPUT_SEQUENCE_HPP_INCLUDED