diff options
Diffstat (limited to 'boost/context/detail/index_sequence.hpp')
-rw-r--r-- | boost/context/detail/index_sequence.hpp | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/boost/context/detail/index_sequence.hpp b/boost/context/detail/index_sequence.hpp new file mode 100644 index 0000000000..2d484ba062 --- /dev/null +++ b/boost/context/detail/index_sequence.hpp @@ -0,0 +1,72 @@ + +// Copyright Oliver Kowalke 2014. +// Distributed under the Boost Software License, Version 1.0. +// (See accompanying file LICENSE_1_0.txt or copy at +// http://www.boost.org/LICENSE_1_0.txt) + +#ifndef BOOST_CONTEXT_DETAIL_INDEX_SEQUENCE_H +#define BOOST_CONTEXT_DETAIL_INDEX_SEQUENCE_H + +#include <cstddef> + +#include <boost/config.hpp> + +#include <boost/context/detail/config.hpp> + +#ifdef BOOST_HAS_ABI_HEADERS +# include BOOST_ABI_PREFIX +#endif + +namespace boost { +namespace context { +namespace detail { + +#if ! defined(BOOST_CONTEXT_NO_CXX14_INTEGER_SEQUENCE) +template< std::size_t ... I > +using index_sequence = std::index_sequence< I ... >; +template< std::size_t I > +using make_index_sequence = std::make_index_sequence< I >; +template< typename ... T > +using index_sequence_for = std::index_sequence_for< T ... >; +#else +//http://stackoverflow.com/questions/17424477/implementation-c14-make-integer-sequence + +template< std::size_t ... I > +struct index_sequence { + using type = index_sequence; + using value_type = std::size_t; + static constexpr std::size_t size() { + return sizeof ... (I); + } +}; + +template< typename Seq1, typename Seq2 > +struct concat_sequence; + +template< std::size_t ... I1, std::size_t ... I2 > +struct concat_sequence< index_sequence< I1 ... >, index_sequence< I2 ... > > : public index_sequence< I1 ..., (sizeof ... (I1)+I2) ... > { +}; + +template< std::size_t I > +struct make_index_sequence : public concat_sequence< typename make_index_sequence< I/2 >::type, + typename make_index_sequence< I-I/2 >::type > { +}; + +template<> +struct make_index_sequence< 0 > : public index_sequence<> { +}; +template<> +struct make_index_sequence< 1 > : public index_sequence< 0 > { +}; + +template< typename ... T > +using index_sequence_for = make_index_sequence< sizeof ... (T) >; +#endif + +}}} + +#ifdef BOOST_HAS_ABI_HEADERS +#include BOOST_ABI_SUFFIX +#endif + +#endif // BOOST_CONTEXT_DETAIL_INDEX_SEQUENCE_H |