ceph/src/boost/boost/poly_collection/detail/integer_sequence.hpp

   1 /* Copyright 2016 Joaquin M Lopez Munoz.
   2  * Distributed under the Boost Software License, Version 1.0.
   3  * (See accompanying file LICENSE_1_0.txt or copy at
   4  * http://www.boost.org/LICENSE_1_0.txt)
   5  *
   6  * See http://www.boost.org/libs/poly_collection for library home page.
   7  */
   8
   9 #ifndef BOOST_POLY_COLLECTION_DETAIL_INTEGER_SEQUENCE_HPP
  10 #define BOOST_POLY_COLLECTION_DETAIL_INTEGER_SEQUENCE_HPP
  11
  12 #if defined(_MSC_VER)
  13 #pragma once
  14 #endif
  15
  16 #include <cstddef>
  17
  18 namespace boost{
  19
  20 namespace poly_collection{
  21
  22 namespace detail{
  23
  24 /* ripped from http://pdimov.com/cpp2/simple_cxx11_metaprogramming.html */
  25
  26 template<typename T,T... Ints> struct integer_sequence{};
  27
  28 template<typename S> struct next_integer_sequence;
  29
  30 template<typename T,T... Ints>
  31 struct next_integer_sequence<integer_sequence<T,Ints...>>
  32 {
  33   using type=integer_sequence<T,Ints...,sizeof...(Ints)>;
  34 };
  35
  36 template<typename T,T I,T N> struct make_int_seq_impl;
  37
  38 template<typename T,T N>
  39 using make_integer_sequence=typename make_int_seq_impl<T,0,N>::type;
  40
  41 template<typename T,T I,T N> struct make_int_seq_impl
  42 {
  43   using type=typename next_integer_sequence<
  44     typename make_int_seq_impl<T,I+1,N>::type>::type;
  45 };
  46
  47 template<typename T,T N> struct make_int_seq_impl<T,N,N>
  48 {
  49   using type=integer_sequence<T>;
  50 };
  51
  52 template<std::size_t... Ints>
  53 using index_sequence=integer_sequence<std::size_t,Ints...>;
  54
  55 template<std::size_t N>
  56 using make_index_sequence=make_integer_sequence<std::size_t,N>;
  57
  58 } /* namespace poly_collection::detail */
  59
  60 } /* namespace poly_collection */
  61
  62 } /* namespace boost */
  63
  64 #endif