projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | /*! |
| 2 | @file | |
| 3 | Forward declares `boost::hana::negate`. | |
| 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_FWD_NEGATE_HPP | |
| 11 | #define BOOST_HANA_FWD_NEGATE_HPP | |
| 12 | ||
| 13 | #include <boost/hana/config.hpp> | |
| 14 | #include <boost/hana/core/when.hpp> | |
| 15 | ||
| 16 | ||
| 17 | BOOST_HANA_NAMESPACE_BEGIN | |
| 18 | //! Return the inverse of an element of a group. | |
| 19 | //! @ingroup group-Group | |
| 20 | //! | |
| 21 | //! | |
| 22 | //! Example | |
| 23 | //! ------- | |
| 24 | //! @include example/negate.cpp | |
| 25 | #ifdef BOOST_HANA_DOXYGEN_INVOKED | |
| 26 | constexpr auto negate = [](auto&& x) -> decltype(auto) { | |
| 27 | return tag-dispatched; | |
| 28 | }; | |
| 29 | #else | |
| 30 | template <typename G, typename = void> | |
| 31 | struct negate_impl : negate_impl<G, when<true>> { }; | |
| 32 | ||
| 33 | struct negate_t { | |
| 34 | template <typename X> | |
| 35 | constexpr decltype(auto) operator()(X&& x) const; | |
| 36 | }; | |
| 37 | ||
| 38 | constexpr negate_t negate{}; | |
| 39 | #endif | |
| 40 | BOOST_HANA_NAMESPACE_END | |
| 41 | ||
| 42 | #endif // !BOOST_HANA_FWD_NEGATE_HPP |