projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | /*! |
| 2 | @file | |
| 3 | Forward declares `boost::hana::for_each`. | |
| 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_FOR_EACH_HPP | |
| 11 | #define BOOST_HANA_FWD_FOR_EACH_HPP | |
| 12 | ||
| 13 | #include <boost/hana/config.hpp> | |
| 14 | #include <boost/hana/core/when.hpp> | |
| 15 | ||
| 16 | ||
| 17 | BOOST_HANA_NAMESPACE_BEGIN | |
| 18 | //! Perform an action on each element of a foldable, discarding | |
| 19 | //! the result each time. | |
| 20 | //! @ingroup group-Foldable | |
| 21 | //! | |
| 22 | //! Iteration is done from left to right, i.e. in the same order as when | |
| 23 | //! using `fold_left`. If the structure is not finite, this method will | |
| 24 | //! not terminate. | |
| 25 | //! | |
| 26 | //! | |
| 27 | //! @param xs | |
| 28 | //! The structure to iterate over. | |
| 29 | //! | |
| 30 | //! @param f | |
| 31 | //! A function called as `f(x)` for each element `x` of the structure. | |
| 32 | //! The result of `f(x)`, whatever it is, is ignored. | |
| 33 | //! | |
| 34 | //! | |
| 35 | //! Example | |
| 36 | //! ------- | |
| 37 | //! @include example/for_each.cpp | |
| 38 | #ifdef BOOST_HANA_DOXYGEN_INVOKED | |
| 39 | constexpr auto for_each = [](auto&& xs, auto&& f) -> void { | |
| 40 | tag-dispatched; | |
| 41 | }; | |
| 42 | #else | |
| 43 | template <typename T, typename = void> | |
| 44 | struct for_each_impl : for_each_impl<T, when<true>> { }; | |
| 45 | ||
| 46 | struct for_each_t { | |
| 47 | template <typename Xs, typename F> | |
| 48 | constexpr void operator()(Xs&& xs, F&& f) const; | |
| 49 | }; | |
| 50 | ||
| 51 | constexpr for_each_t for_each{}; | |
| 52 | #endif | |
| 53 | BOOST_HANA_NAMESPACE_END | |
| 54 | ||
| 55 | #endif // !BOOST_HANA_FWD_FOR_EACH_HPP |