v3/view/remove.hpp

0001 /// \file
0002 // Range v3 library
0003 //
0004 //  Copyright Andrey Diduh 2019
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_VIEW_REMOVE_HPP
0015 #define RANGES_V3_VIEW_REMOVE_HPP
0016
0017 #include <type_traits>
0018 #include <utility>
0019
0020 #include <meta/meta.hpp>
0021
0022 #include <concepts/concepts.hpp>
0023
0024 #include <range/v3/range_fwd.hpp>
0025
0026 #include <range/v3/functional/bind_back.hpp>
0027 #include <range/v3/functional/comparisons.hpp>
0028 #include <range/v3/view/remove_if.hpp>
0029 #include <range/v3/view/view.hpp>
0030
0031 #include <range/v3/detail/prologue.hpp>
0032
0033 namespace ranges
0034 {
0035     /// \addtogroup group-views
0036     /// @{
0037     namespace views
0038     {
0039         struct remove_base_fn
0040         {
0041         private:
0042             template<typename Value>
0043             struct pred_
0044             {
0045                 Value value_;
0046                 template(typename T)(
0047                     requires equality_comparable_with<T, Value const &>)
0048                 bool operator()(T && other) const
0049                 {
0050                     return static_cast<T &&>(other) == value_;
0051                 }
0052             };
0053
0054         public:
0055             template(typename Rng, typename Value)(
0056                 requires move_constructible<Value> AND viewable_range<Rng> AND
0057                     input_range<Rng> AND
0058                     indirectly_comparable<iterator_t<Rng>, Value const *, equal_to>)
0059             constexpr auto operator()(Rng && rng, Value value) const
0060             {
0061                 return remove_if(static_cast<Rng &&>(rng),
0062                                  pred_<Value>{std::move(value)});
0063             }
0064
0065             template(typename Rng, typename Value, typename Proj)(
0066                 requires move_constructible<Value> AND viewable_range<Rng> AND
0067                     input_range<Rng> AND
0068                     indirectly_comparable<iterator_t<Rng>, Value const *, equal_to, Proj>)
0069             constexpr auto operator()(Rng && rng, Value value, Proj proj) const
0070             {
0071                 return remove_if(static_cast<Rng &&>(rng),
0072                                  pred_<Value>{std::move(value)},
0073                                  std::move(proj));
0074             }
0075         };
0076
0077         struct remove_bind_fn
0078         {
0079             template<typename Value>
0080             constexpr auto operator()(Value value) const // TODO: underconstrained
0081             {
0082                 return make_view_closure(bind_back(remove_base_fn{}, std::move(value)));
0083             }
0084             template(typename Value, typename Proj)(
0085                 requires (!range<Value>)) // TODO: underconstrained
0086             constexpr auto operator()(Value && value, Proj proj) const
0087             {
0088                 return make_view_closure(bind_back(
0089                     remove_base_fn{}, static_cast<Value &&>(value), std::move(proj)));
0090             }
0091         };
0092
0093         struct RANGES_EMPTY_BASES remove_fn
0094           : remove_base_fn, remove_bind_fn
0095         {
0096             using remove_base_fn::operator();
0097             using remove_bind_fn::operator();
0098         };
0099
0100         /// \relates remove_fn
0101         /// \ingroup group-views
0102         RANGES_INLINE_VARIABLE(remove_fn, remove)
0103     } // namespace views
0104     /// @}
0105 } // namespace ranges
0106
0107 #include <range/v3/detail/epilogue.hpp>
0108
0109 #endif // RANGES_V3_VIEW_REMOVE_HPP