ceph/src/boost/libs/property_tree/include/boost/property_tree/json_parser/detail/read.hpp

   1 // ----------------------------------------------------------------------------
   2 // Copyright (C) 2015 Sebastian Redl
   3 //
   4 // Distributed under the Boost Software License, Version 1.0.
   5 // (See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt)
   7 //
   8 // For more information, see www.boost.org
   9 // ----------------------------------------------------------------------------
  10 #ifndef BOOST_PROPERTY_TREE_DETAIL_JSON_PARSER_READ_HPP
  11 #define BOOST_PROPERTY_TREE_DETAIL_JSON_PARSER_READ_HPP
  12
  13 #include <boost/property_tree/json_parser/detail/parser.hpp>
  14 #include <boost/property_tree/json_parser/detail/narrow_encoding.hpp>
  15 #include <boost/property_tree/json_parser/detail/wide_encoding.hpp>
  16 #include <boost/property_tree/json_parser/detail/standard_callbacks.hpp>
  17
  18 #include <boost/static_assert.hpp>
  19 #include <boost/type_traits/is_same.hpp>
  20
  21 #include <istream>
  22 #include <iterator>
  23 #include <string>
  24
  25 namespace boost { namespace property_tree {
  26     namespace json_parser { namespace detail
  27 {
  28
  29     template <typename Iterator, typename Sentinel>
  30     class minirange
  31     {
  32     public:
  33         minirange(Iterator first, Sentinel last) : first(first), last(last) {}
  34         Iterator begin() const { return first; }
  35         Sentinel end() const { return last; }
  36
  37     private:
  38         Iterator first;
  39         Sentinel last;
  40     };
  41     template <typename Iterator, typename Sentinel>
  42     minirange<Iterator, Sentinel> make_minirange(Iterator first, Sentinel last)
  43     {
  44         return minirange<Iterator, Sentinel>(first, last);
  45     }
  46
  47     template <typename Iterator, typename Sentinel,
  48               typename Encoding, typename Callbacks>
  49     void read_json_internal(Iterator first, Sentinel last, Encoding& encoding,
  50         Callbacks& callbacks, const std::string& filename)
  51     {
  52         BOOST_STATIC_ASSERT_MSG((boost::is_same<
  53             typename std::iterator_traits<Iterator>::value_type,
  54             typename Encoding::external_char>::value),
  55             "Encoding is not capable of using the iterator's value type.");
  56         BOOST_STATIC_ASSERT_MSG((boost::is_same<
  57             typename Callbacks::char_type,
  58             typename Encoding::internal_char>::value),
  59             "Encoding is not capable of producing the needed character type.");
  60
  61         detail::parser<Callbacks, Encoding, Iterator, Sentinel>
  62             parser(callbacks, encoding);
  63         parser.set_input(filename, make_minirange(first, last));
  64         parser.parse_value();
  65         parser.finish();
  66     }
  67
  68     template <typename Ch> struct encoding;
  69     template <> struct encoding<char> : utf8_utf8_encoding {};
  70     template <> struct encoding<wchar_t> : wide_wide_encoding {};
  71
  72     template <typename Ptree>
  73     void read_json_internal(
  74         std::basic_istream<typename Ptree::key_type::value_type> &stream,
  75         Ptree &pt, const std::string &filename)
  76     {
  77         typedef typename Ptree::key_type::value_type char_type;
  78         typedef standard_callbacks<Ptree> callbacks_type;
  79         typedef detail::encoding<char_type> encoding_type;
  80         typedef std::istreambuf_iterator<char_type> iterator;
  81         callbacks_type callbacks;
  82         encoding_type encoding;
  83         read_json_internal(iterator(stream), iterator(),
  84             encoding, callbacks, filename);
  85         pt.swap(callbacks.output());
  86     }
  87
  88 }}}}
  89
  90 #endif