ceph/src/boost/boost/spirit/home/karma/detail/attributes.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(SPIRIT_KARMA_DETAIL_ATTRIBUTES_APR_18_2010_0453PM)
   8 #define SPIRIT_KARMA_DETAIL_ATTRIBUTES_APR_18_2010_0453PM
   9
  10 #include <boost/spirit/home/karma/domain.hpp>
  11 #include <boost/spirit/home/support/attributes_fwd.hpp>
  12 #include <boost/spirit/home/support/attributes.hpp>
  13
  14 ///////////////////////////////////////////////////////////////////////////////
  15 namespace boost { namespace spirit { namespace karma
  16 {
  17     template <typename Exposed, typename Transformed, typename Enable = void>
  18     struct transform_attribute
  19     {
  20         typedef Transformed type;
  21         static Transformed pre(Exposed& val)
  22         {
  23             return Transformed(traits::extract_from<Transformed>(val, unused));
  24         }
  25         // Karma only, no post() and no fail() required
  26     };
  27
  28     template <typename Exposed, typename Transformed>
  29     struct transform_attribute<boost::optional<Exposed> const, Transformed
  30       , typename disable_if<is_same<boost::optional<Exposed>, Transformed> >::type>
  31     {
  32         typedef Transformed const& type;
  33         static Transformed const& pre(boost::optional<Exposed> const& val)
  34         {
  35             return boost::get<Transformed>(val);
  36         }
  37     };
  38
  39     template <typename Attribute>
  40     struct transform_attribute<Attribute const, Attribute>
  41     {
  42         typedef Attribute const& type;
  43         static Attribute const& pre(Attribute const& val) { return val; }
  44         // Karma only, no post() and no fail() required
  45     };
  46
  47     // reference types need special handling
  48     template <typename Exposed, typename Transformed>
  49     struct transform_attribute<Exposed&, Transformed>
  50       : transform_attribute<Exposed, Transformed>
  51     {};
  52
  53     template <typename Exposed, typename Transformed>
  54     struct transform_attribute<Exposed const&, Transformed>
  55       : transform_attribute<Exposed const, Transformed>
  56     {};
  57
  58     template <typename Attribute>
  59     struct transform_attribute<Attribute const&, Attribute>
  60       : transform_attribute<Attribute const, Attribute>
  61     {};
  62
  63     // unused_type needs some special handling as well
  64     template <>
  65     struct transform_attribute<unused_type, unused_type>
  66     {
  67         typedef unused_type type;
  68         static unused_type pre(unused_type) { return unused; }
  69     };
  70
  71     template <>
  72     struct transform_attribute<unused_type const, unused_type>
  73       : transform_attribute<unused_type, unused_type>
  74     {};
  75
  76     template <typename Attribute>
  77     struct transform_attribute<unused_type, Attribute>
  78       : transform_attribute<unused_type, unused_type>
  79     {};
  80
  81     template <typename Attribute>
  82     struct transform_attribute<unused_type const, Attribute>
  83       : transform_attribute<unused_type, unused_type>
  84     {};
  85
  86     template <typename Attribute>
  87     struct transform_attribute<Attribute, unused_type>
  88       : transform_attribute<unused_type, unused_type>
  89     {};
  90
  91     template <typename Attribute>
  92     struct transform_attribute<Attribute const, unused_type>
  93       : transform_attribute<unused_type, unused_type>
  94     {};
  95 }}}
  96
  97 ///////////////////////////////////////////////////////////////////////////////
  98 namespace boost { namespace spirit { namespace traits
  99 {
 100     template <typename Exposed, typename Transformed>
 101     struct transform_attribute<Exposed, Transformed, karma::domain>
 102       : karma::transform_attribute<Exposed, Transformed>
 103     {};
 104 }}}
 105
 106 #endif
 107
 108