projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | /*! |
| 2 | @file | |
| 3 | Defines `boost::hana::replicate`. | |
| 4 | ||
| 5 | @copyright Louis Dionne 2013-2016 | |
| 6 | Distributed under the Boost Software License, Version 1.0. | |
| 7 | (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt) | |
| 8 | */ | |
| 9 | ||
| 10 | #ifndef BOOST_HANA_REPLICATE_HPP | |
| 11 | #define BOOST_HANA_REPLICATE_HPP | |
| 12 | ||
| 13 | #include <boost/hana/fwd/replicate.hpp> | |
| 14 | ||
| 15 | #include <boost/hana/concept/integral_constant.hpp> | |
| 16 | #include <boost/hana/concept/monad_plus.hpp> | |
| 17 | #include <boost/hana/config.hpp> | |
| 18 | #include <boost/hana/core/dispatch.hpp> | |
| 19 | #include <boost/hana/core/make.hpp> | |
| 20 | #include <boost/hana/cycle.hpp> | |
| 21 | #include <boost/hana/lift.hpp> | |
| 22 | ||
| 23 | #include <cstddef> | |
| 24 | #include <utility> | |
| 25 | ||
| 26 | ||
| 27 | BOOST_HANA_NAMESPACE_BEGIN | |
| 28 | template <typename M> | |
| 29 | struct replicate_t { | |
| 30 | #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS | |
| 31 | static_assert(hana::MonadPlus<M>::value, | |
| 32 | "hana::replicate<M>(x, n) requires 'M' to be a MonadPlus"); | |
| 33 | #endif | |
| 34 | ||
| 35 | template <typename X, typename N> | |
| 36 | constexpr auto operator()(X&& x, N const& n) const { | |
| 37 | using Replicate = BOOST_HANA_DISPATCH_IF(replicate_impl<M>, | |
| 38 | hana::MonadPlus<M>::value && | |
| 39 | hana::IntegralConstant<N>::value | |
| 40 | ); | |
| 41 | ||
| 42 | #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS | |
| 43 | static_assert(hana::IntegralConstant<N>::value, | |
| 44 | "hana::replicate<M>(x, n) requires 'n' to be an IntegralConstant"); | |
| 45 | #endif | |
| 46 | ||
| 47 | return Replicate::apply(static_cast<X&&>(x), n); | |
| 48 | } | |
| 49 | }; | |
| 50 | ||
| 51 | template <typename M, bool condition> | |
| 52 | struct replicate_impl<M, when<condition>> : default_ { | |
| 53 | template <typename X, typename N> | |
| 54 | static constexpr auto apply(X&& x, N const& n) { | |
| 55 | return hana::cycle(hana::lift<M>(static_cast<X&&>(x)), n); | |
| 56 | } | |
| 57 | }; | |
| 58 | ||
| 59 | template <typename S> | |
| 60 | struct replicate_impl<S, when<Sequence<S>::value>> { | |
| 61 | template <typename X, std::size_t ...i> | |
| 62 | static constexpr auto replicate_helper(X&& x, std::index_sequence<i...>) | |
| 63 | { return hana::make<S>(((void)i, x)...); } | |
| 64 | ||
| 65 | template <typename X, typename N> | |
| 66 | static constexpr auto apply(X&& x, N const&) { | |
| 67 | constexpr std::size_t n = N::value; | |
| 68 | return replicate_helper(static_cast<X&&>(x), | |
| 69 | std::make_index_sequence<n>{}); | |
| 70 | } | |
| 71 | }; | |
| 72 | BOOST_HANA_NAMESPACE_END | |
| 73 | ||
| 74 | #endif // !BOOST_HANA_REPLICATE_HPP |