projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | /*! |
| 2 | @file | |
| 3 | Defines `boost::hana::insert`. | |
| 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_INSERT_HPP | |
| 11 | #define BOOST_HANA_INSERT_HPP | |
| 12 | ||
| 13 | #include <boost/hana/fwd/insert.hpp> | |
| 14 | ||
| 15 | #include <boost/hana/append.hpp> | |
| 16 | #include <boost/hana/concat.hpp> | |
| 17 | #include <boost/hana/concept/sequence.hpp> | |
| 18 | #include <boost/hana/config.hpp> | |
| 19 | #include <boost/hana/core/dispatch.hpp> | |
| 20 | #include <boost/hana/drop_front.hpp> | |
| 21 | #include <boost/hana/take_front.hpp> | |
| 22 | ||
| 23 | ||
| 24 | BOOST_HANA_NAMESPACE_BEGIN | |
| 25 | //! @cond | |
| 26 | template <typename Set, typename ...Args> | |
| 27 | constexpr decltype(auto) insert_t::operator()(Set&& set, Args&& ...args) const { | |
| 28 | return insert_impl<typename hana::tag_of<Set>::type>::apply( | |
| 29 | static_cast<Set&&>(set), | |
| 30 | static_cast<Args&&>(args)... | |
| 31 | ); | |
| 32 | } | |
| 33 | //! @endcond | |
| 34 | ||
| 35 | template <typename T, bool condition> | |
| 36 | struct insert_impl<T, when<condition>> : default_ { | |
| 37 | template <typename ...Args> | |
| 38 | static constexpr auto apply(Args&& ...) = delete; | |
| 39 | }; | |
| 40 | ||
| 41 | template <typename S> | |
| 42 | struct insert_impl<S, when<Sequence<S>::value>> { | |
| 43 | template <typename Xs, typename N, typename Element> | |
| 44 | static constexpr auto apply(Xs&& xs, N const& n, Element&& e) { | |
| 45 | return hana::concat(hana::append(hana::take_front(xs, n), | |
| 46 | static_cast<Element&&>(e)), | |
| 47 | hana::drop_front(xs, n)); | |
| 48 | } | |
| 49 | }; | |
| 50 | BOOST_HANA_NAMESPACE_END | |
| 51 | ||
| 52 | #endif // !BOOST_HANA_INSERT_HPP |