v3/action/split_when.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_WHEN_HPP
0015 #define RANGES_V3_ACTION_SPLIT_WHEN_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/functional/invoke.hpp>
0027 #include <range/v3/iterator/concepts.hpp>
0028 #include <range/v3/iterator/traits.hpp>
0029 #include <range/v3/range/conversion.hpp>
0030 #include <range/v3/utility/static_const.hpp>
0031 #include <range/v3/view/split_when.hpp>
0032
0033 #include <range/v3/detail/prologue.hpp>
0034
0035 namespace ranges
0036 {
0037     /// \addtogroup group-actions
0038     /// @{
0039     namespace actions
0040     {
0041         struct split_when_fn
0042         {
0043             template<typename Rng>
0044             using split_value_t =
0045                 meta::if_c<(bool)ranges::container<Rng>, //
0046                            uncvref_t<Rng>, std::vector<range_value_t<Rng>>>;
0047
0048             template<typename Fun>
0049             constexpr auto operator()(Fun fun) const
0050             {
0051                 return make_action_closure(
0052                     bind_back(split_when_fn{}, static_cast<Fun &&>(fun)));
0053             }
0054
0055             // BUGBUG something is not right with the actions. It should be possible
0056             // to move a container into a split and have elements moved into the result.
0057             template(typename Rng, typename Fun)(
0058                 requires forward_range<Rng> AND
0059                         invocable<Fun &, iterator_t<Rng>, sentinel_t<Rng>> AND
0060                             invocable<Fun &, iterator_t<Rng>, iterator_t<Rng>> AND
0061                                 copy_constructible<Fun> AND
0062                                     convertible_to<invoke_result_t<Fun &, iterator_t<Rng>,
0063                                                                    sentinel_t<Rng>>,
0064                                                    std::pair<bool, iterator_t<Rng>>>)
0065             std::vector<split_value_t<Rng>> operator()(Rng && rng, Fun fun) const
0066             {
0067                 return views::split_when(rng, std::move(fun)) |
0068                        to<std::vector<split_value_t<Rng>>>();
0069             }
0070
0071             template(typename Rng, typename Fun)(
0072                 requires forward_range<Rng> AND
0073                         predicate<Fun const &, range_reference_t<Rng>> AND
0074                             copy_constructible<Fun>)
0075             std::vector<split_value_t<Rng>> operator()(Rng && rng, Fun fun) const
0076             {
0077                 return views::split_when(rng, std::move(fun)) |
0078                        to<std::vector<split_value_t<Rng>>>();
0079             }
0080         };
0081
0082         /// \relates actions::split_when_fn
0083         RANGES_INLINE_VARIABLE(split_when_fn, split_when)
0084     } // namespace actions
0085     /// @}
0086 } // namespace ranges
0087
0088 #include <range/v3/detail/epilogue.hpp>
0089
0090 #endif