ceph/src/boost/boost/convert/detail/boost_parameter_ext.hpp

   1 // Copyright (c) 2009-2016 Vladimir Batov.
   2 // Use, modification and distribution are subject to the Boost Software License,
   3 // Version 1.0. See http://www.boost.org/LICENSE_1_0.txt.
   4
   5 #ifndef BOOST_PARAMETER_EXT_PRIVATE_HPP
   6 #define BOOST_PARAMETER_EXT_PRIVATE_HPP
   7
   8 #include <boost/parameter/keyword.hpp>
   9
  10 // A Boost.Parameter extension by Andrey Semashev.
  11 // This should really go to Boost.Parameter in the end.
  12
  13 namespace boost { namespace parameter {
  14
  15 // The metafunction, given the type of the arguments pack and the keyword tag,
  16 // returns the corresponding parameter type
  17 template< typename ArgsT, typename KeywordTagT >
  18 struct parameter_type
  19 {
  20     typedef void type;
  21 };
  22
  23 template< typename ArgT, typename KeywordTagT >
  24 struct parameter_type<aux::tagged_argument<KeywordTagT, ArgT>, KeywordTagT>
  25 {
  26     typedef typename aux::tagged_argument< KeywordTagT, ArgT >::value_type type;
  27 };
  28
  29 template< typename KeywordTagT1, typename ArgT, typename KeywordTagT2 >
  30 struct parameter_type< aux::tagged_argument< KeywordTagT1, ArgT >, KeywordTagT2 >
  31 {
  32     typedef void type;
  33 };
  34
  35 template< typename ArgT, typename TailT, typename KeywordTagT >
  36 struct parameter_type<
  37     aux::arg_list<
  38         aux::tagged_argument< KeywordTagT, ArgT >,
  39         TailT
  40     >,
  41     KeywordTagT
  42 >
  43 {
  44     typedef typename aux::tagged_argument< KeywordTagT, ArgT >::value_type type;
  45 };
  46
  47 template< typename KeywordTagT1, typename ArgT, typename TailT, typename KeywordTagT2 >
  48 struct parameter_type<
  49     aux::arg_list<
  50         aux::tagged_argument< KeywordTagT1, ArgT >,
  51         TailT
  52     >,
  53     KeywordTagT2
  54 > :
  55     public parameter_type< TailT, KeywordTagT2 >
  56 {
  57 };
  58
  59 }} // boost::parameter
  60
  61 #endif // BOOST_PARAMETER_EXT_PRIVATE_HPP
  62