ceph/src/boost/boost/spirit/home/support/detail/get_encoding.hpp

   1 //  Copyright (c) 2001-2011 Hartmut Kaiser
   2 //  Copyright (c) 2001-2011 Joel de Guzman
   3 //
   4 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
   5 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #if !defined(BOOST_SPIRIT_GET_ENCODING_JANUARY_13_2009_1255PM)
   8 #define BOOST_SPIRIT_GET_ENCODING_JANUARY_13_2009_1255PM
   9
  10 #if defined(_MSC_VER)
  11 #pragma once
  12 #endif
  13
  14 #include <boost/mpl/identity.hpp>
  15 #include <boost/type_traits/is_same.hpp>
  16
  17 namespace boost { namespace spirit { namespace detail
  18 {
  19     template <typename Modifiers, typename Encoding>
  20     struct get_implicit_encoding
  21     {
  22         // Extract the implicit encoding from the Modifiers
  23         // If one is not found, Encoding is used. The explicit
  24         // encoding is the first viable encoding that can be
  25         // extracted from the Modifiers (there can be more than one).
  26
  27         typedef typename
  28             mpl::find_if<
  29                 char_encodings,
  30                 has_modifier<Modifiers, tag::char_encoding_base<mpl::_1> >
  31             >::type
  32         iter;
  33
  34         typedef typename
  35             mpl::eval_if<
  36                 is_same<iter, typename mpl::end<char_encodings>::type>,
  37                 mpl::identity<Encoding>,
  38                 mpl::deref<iter>
  39             >::type
  40         type;
  41     };
  42
  43     template <typename Modifiers, typename Encoding>
  44     struct get_encoding
  45     {
  46         // Extract the explicit encoding from the Modifiers
  47         // If one is not found, get implicit encoding (see above).
  48         // Explicit encoding is the encoding explicitly declared
  49         // using the encoding[c] directive.
  50
  51         typedef typename
  52             mpl::find_if<
  53                 char_encodings,
  54                 has_modifier<Modifiers, tag::char_code<tag::encoding, mpl::_1> >
  55             >::type
  56         iter;
  57
  58         typedef typename
  59             mpl::eval_if<
  60                 is_same<iter, typename mpl::end<char_encodings>::type>,
  61                 get_implicit_encoding<Modifiers, Encoding>,
  62                 mpl::deref<iter>
  63             >::type
  64         type;
  65     };
  66
  67     template <typename Modifiers, typename Encoding, bool case_modifier = false>
  68     struct get_encoding_with_case : mpl::identity<Encoding> {};
  69
  70     template <typename Modifiers, typename Encoding>
  71     struct get_encoding_with_case<Modifiers, Encoding, true>
  72         : get_encoding<Modifiers, Encoding> {};
  73 }}}
  74
  75 #endif