ceph/src/boost/boost/type_erasure/detail/get_placeholders.hpp

   1 // Boost.TypeErasure library
   2 //
   3 // Copyright 2011 Steven Watanabe
   4 //
   5 // Distributed under the Boost Software License Version 1.0. (See
   6 // accompanying file LICENSE_1_0.txt or copy at
   7 // http://www.boost.org/LICENSE_1_0.txt)
   8 //
   9 // $Id$
  10
  11 #if !defined(BOOST_PP_IS_ITERATING)
  12
  13 #ifndef BOOST_TYPE_ERASURE_DETAIL_GET_PLACEHOLDERS_HPP_INCLUDED
  14 #define BOOST_TYPE_ERASURE_DETAIL_GET_PLACEHOLDERS_HPP_INCLUDED
  15
  16 #include <boost/mpl/eval_if.hpp>
  17 #include <boost/mpl/identity.hpp>
  18 #include <boost/mpl/insert.hpp>
  19 #include <boost/preprocessor/cat.hpp>
  20 #include <boost/preprocessor/iteration/iterate.hpp>
  21 #include <boost/preprocessor/repetition/enum.hpp>
  22 #include <boost/preprocessor/repetition/enum_params.hpp>
  23 #include <boost/preprocessor/repetition/enum_trailing_params.hpp>
  24 #include <boost/type_erasure/config.hpp>
  25 #include <boost/type_erasure/is_placeholder.hpp>
  26
  27 namespace boost {
  28 namespace type_erasure {
  29 namespace detail {
  30
  31 template<class T, class Out>
  32 struct get_placeholders_in_argument
  33 {
  34     typedef typename ::boost::mpl::eval_if<
  35         ::boost::type_erasure::is_placeholder<T>,
  36         ::boost::mpl::insert<Out, T>,
  37         ::boost::mpl::identity<Out>
  38     >::type type;
  39 };
  40
  41 template<class T, class Out>
  42 struct get_placeholders;
  43
  44 template<class T, class Out>
  45 struct get_placeholders_in_argument<T&, Out>
  46 {
  47     typedef typename ::boost::type_erasure::detail::get_placeholders_in_argument<
  48         T,
  49         Out
  50     >::type type;
  51 };
  52
  53 template<class T, class Out>
  54 struct get_placeholders_in_argument<const T, Out>
  55 {
  56     typedef typename ::boost::type_erasure::detail::get_placeholders_in_argument<
  57         T,
  58         Out
  59     >::type type;
  60 };
  61
  62 #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
  63
  64 template<class Out, class... T>
  65 struct get_placeholders_impl;
  66
  67 template<class Out, class T0, class... T>
  68 struct get_placeholders_impl<Out, T0, T...>
  69 {
  70     typedef typename ::boost::type_erasure::detail::get_placeholders_in_argument<
  71         T0,
  72         typename get_placeholders_impl<Out, T...>::type
  73     >::type type;
  74 };
  75
  76 template<class Out>
  77 struct get_placeholders_impl<Out>
  78 {
  79     typedef Out type;
  80 };
  81
  82 template<template<class...> class T, class... U, class Out>
  83 struct get_placeholders<T<U...>, Out>
  84 {
  85     typedef typename get_placeholders_impl<Out, U...>::type type;
  86 };
  87
  88 template<class R, class... T, class Out>
  89 struct get_placeholders_in_argument<R(T...), Out>
  90 {
  91     typedef typename ::boost::type_erasure::detail::get_placeholders_in_argument<
  92         R,
  93         Out
  94     >::type type0;
  95     typedef typename get_placeholders_impl<type0, T...>::type type;
  96 };
  97
  98 #else
  99
 100 #define BOOST_PP_FILENAME_1 <boost/type_erasure/detail/get_placeholders.hpp>
 101 #define BOOST_PP_ITERATION_LIMITS (0, BOOST_TYPE_ERASURE_MAX_ARITY)
 102 #include BOOST_PP_ITERATE()
 103
 104 #endif
 105
 106 }
 107 }
 108 }
 109
 110 #endif
 111
 112 #else
 113
 114 #define N BOOST_PP_ITERATION()
 115 #define BOOST_TYPE_ERASURE_GET_PLACEHOLDER(z, n, data)                              \
 116     typedef typename ::boost::type_erasure::detail::get_placeholders_in_argument<   \
 117         BOOST_PP_CAT(data, n), BOOST_PP_CAT(type, n)>::type                         \
 118         BOOST_PP_CAT(type, BOOST_PP_INC(n));
 119
 120 #if N != 0
 121
 122 template<template<BOOST_PP_ENUM_PARAMS(N, class T)> class T,
 123     BOOST_PP_ENUM_PARAMS(N, class T), class Out>
 124 struct get_placeholders<T<BOOST_PP_ENUM_PARAMS(N, T)>, Out>
 125 {
 126     typedef Out type0;
 127     BOOST_PP_REPEAT(N, BOOST_TYPE_ERASURE_GET_PLACEHOLDER, T)
 128     typedef BOOST_PP_CAT(type, N) type;
 129 };
 130
 131 #endif
 132
 133 template<class R
 134     BOOST_PP_ENUM_TRAILING_PARAMS(N, class T), class Out>
 135 struct get_placeholders_in_argument<R(BOOST_PP_ENUM_PARAMS(N, T)), Out>
 136 {
 137     typedef typename ::boost::type_erasure::detail::get_placeholders_in_argument<
 138         R,
 139         Out
 140     >::type type0;
 141     BOOST_PP_REPEAT(N, BOOST_TYPE_ERASURE_GET_PLACEHOLDER, T)
 142     typedef BOOST_PP_CAT(type, N) type;
 143 };
 144
 145 #undef BOOST_TYPE_ERASURE_GET_PLACEHOLDER
 146 #undef N
 147
 148 #endif