projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | /*! |
| 2 | @file | |
| 3 | Defines `boost::hana::zip_shortest_with`. | |
| 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_ZIP_SHORTEST_WITH_HPP | |
| 11 | #define BOOST_HANA_ZIP_SHORTEST_WITH_HPP | |
| 12 | ||
| 13 | #include <boost/hana/fwd/zip_shortest_with.hpp> | |
| 14 | ||
| 15 | #include <boost/hana/concept/sequence.hpp> | |
| 16 | #include <boost/hana/core/dispatch.hpp> | |
| 17 | #include <boost/hana/config.hpp> | |
| 18 | #include <boost/hana/detail/algorithm.hpp> | |
| 19 | #include <boost/hana/detail/fast_and.hpp> | |
| 20 | #include <boost/hana/integral_constant.hpp> | |
| 21 | #include <boost/hana/length.hpp> | |
| 22 | #include <boost/hana/take_front.hpp> | |
| 23 | #include <boost/hana/zip_with.hpp> | |
| 24 | ||
| 25 | #include <cstddef> | |
| 26 | ||
| 27 | ||
| 28 | BOOST_HANA_NAMESPACE_BEGIN | |
| 29 | //! @cond | |
| 30 | template <typename F, typename Xs, typename ...Ys> | |
| 31 | constexpr auto | |
| 32 | zip_shortest_with_t::operator()(F&& f, Xs&& xs, Ys&& ...ys) const { | |
| 33 | #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS | |
| 34 | static_assert(detail::fast_and< | |
| 35 | hana::Sequence<Xs>::value, hana::Sequence<Ys>::value... | |
| 36 | >::value, | |
| 37 | "hana::zip_shortest_with(f, xs, ys...) requires 'xs' and 'ys...' to be Sequences"); | |
| 38 | #endif | |
| 39 | ||
| 40 | return zip_shortest_with_impl<typename hana::tag_of<Xs>::type>::apply( | |
| 41 | static_cast<F&&>(f), | |
| 42 | static_cast<Xs&&>(xs), | |
| 43 | static_cast<Ys&&>(ys)... | |
| 44 | ); | |
| 45 | } | |
| 46 | //! @endcond | |
| 47 | ||
| 48 | template <typename S, bool condition> | |
| 49 | struct zip_shortest_with_impl<S, when<condition>> : default_ { | |
| 50 | template <typename F, typename ...Xs> | |
| 51 | static constexpr decltype(auto) apply(F&& f, Xs&& ...xs) { | |
| 52 | constexpr std::size_t lengths[] = { | |
| 53 | decltype(hana::length(xs))::value... | |
| 54 | }; | |
| 55 | constexpr std::size_t min = *detail::min_element(lengths, lengths + sizeof...(xs)); | |
| 56 | return hana::zip_with(static_cast<F&&>(f), | |
| 57 | hana::take_front(static_cast<Xs&&>(xs), hana::size_c<min>)... | |
| 58 | ); | |
| 59 | } | |
| 60 | }; | |
| 61 | BOOST_HANA_NAMESPACE_END | |
| 62 | ||
| 63 | #endif // !BOOST_HANA_ZIP_SHORTEST_WITH_HPP |