v3/action/split.hpp

0001 /// \file
0002 // Range v3 library
0003 //
0004 //  Copyright Eric Niebler 2013-present
0005 //
0006 //  Use, modification and distribution is subject to the
0007 //  Boost Software License, Version 1.0. (See accompanying
0008 //  file LICENSE_1_0.txt or copy at
0009 //  http://www.boost.org/LICENSE_1_0.txt)
0010 //
0011 // Project home: https://github.com/ericniebler/range-v3
0012 //
0013
0014 #ifndef RANGES_V3_ACTION_SPLIT_HPP
0015 #define RANGES_V3_ACTION_SPLIT_HPP
0016
0017 #include <vector>
0018
0019 #include <meta/meta.hpp>
0020
0021 #include <range/v3/range_fwd.hpp>
0022
0023 #include <range/v3/action/action.hpp>
0024 #include <range/v3/action/concepts.hpp>
0025 #include <range/v3/functional/bind_back.hpp>
0026 #include <range/v3/iterator/concepts.hpp>
0027 #include <range/v3/iterator/traits.hpp>
0028 #include <range/v3/range/conversion.hpp>
0029 #include <range/v3/utility/static_const.hpp>
0030 #include <range/v3/view/split.hpp>
0031
0032 #include <range/v3/detail/prologue.hpp>
0033
0034 namespace ranges
0035 {
0036     /// \addtogroup group-actions
0037     /// @{
0038     namespace actions
0039     {
0040         struct split_fn
0041         {
0042             template<typename Rng>
0043             using split_value_t =
0044                 meta::if_c<(bool)ranges::container<Rng>, //
0045                            uncvref_t<Rng>, std::vector<range_value_t<Rng>>>;
0046
0047             template(typename T)(
0048                 requires range<T &>)
0049             constexpr auto operator()(T & t) const
0050             {
0051                 return make_action_closure(
0052                     bind_back(split_fn{}, detail::reference_wrapper_<T>(t)));
0053             }
0054
0055             template<typename T>
0056             constexpr auto operator()(T && t) const
0057             {
0058                 return make_action_closure(bind_back(split_fn{}, static_cast<T &&>(t)));
0059             }
0060
0061             // BUGBUG something is not right with the actions. It should be possible
0062             // to move a container into a split and have elements moved into the result.
0063             template(typename Rng)(
0064                 requires input_range<Rng> AND indirectly_comparable<
0065                         iterator_t<Rng>, range_value_t<Rng> const *, ranges::equal_to>)
0066             std::vector<split_value_t<Rng>> //
0067             operator()(Rng && rng, range_value_t<Rng> val) const
0068             {
0069                 return views::split(rng, std::move(val)) |
0070                        to<std::vector<split_value_t<Rng>>>();
0071             }
0072
0073             template(typename Rng, typename Pattern)(
0074                 requires input_range<Rng> AND viewable_range<Pattern> AND
0075                     forward_range<Pattern> AND
0076                     indirectly_comparable<
0077                         iterator_t<Rng>,
0078                         iterator_t<Pattern>,
0079                         ranges::equal_to> AND
0080                     (forward_range<Rng> || detail::tiny_range<Pattern>)) //
0081             std::vector<split_value_t<Rng>> operator()(Rng && rng, Pattern && pattern)
0082                 const
0083             {
0084                 return views::split(rng, static_cast<Pattern &&>(pattern)) |
0085                        to<std::vector<split_value_t<Rng>>>();
0086             }
0087
0088             /// \cond
0089             template<typename Rng, typename T>
0090             invoke_result_t<split_fn, Rng, T &> //
0091             operator()(Rng && rng, detail::reference_wrapper_<T> r) const
0092             {
0093                 return (*this)(static_cast<Rng &&>(rng), r.get());
0094             }
0095             /// \endcond
0096         };
0097
0098         /// \relates actions::split_fn
0099         RANGES_INLINE_VARIABLE(split_fn, split)
0100     } // namespace actions
0101     /// @}
0102 } // namespace ranges
0103
0104 #include <range/v3/detail/epilogue.hpp>
0105
0106 #endif