v3/action/unique.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_UNIQUE_HPP
0015 #define RANGES_V3_ACTION_UNIQUE_HPP
0016
0017 #include <range/v3/range_fwd.hpp>
0018
0019 #include <range/v3/action/action.hpp>
0020 #include <range/v3/action/erase.hpp>
0021 #include <range/v3/algorithm/unique.hpp>
0022 #include <range/v3/functional/bind_back.hpp>
0023 #include <range/v3/functional/comparisons.hpp>
0024 #include <range/v3/functional/identity.hpp>
0025 #include <range/v3/iterator/concepts.hpp>
0026 #include <range/v3/range/traits.hpp>
0027 #include <range/v3/utility/static_const.hpp>
0028
0029 #include <range/v3/detail/prologue.hpp>
0030
0031 namespace ranges
0032 {
0033     /// \addtogroup group-actions
0034     /// @{
0035     namespace actions
0036     {
0037         struct unique_fn
0038         {
0039             template(typename C, typename P = identity)(
0040                 requires (!range<C>))
0041             constexpr auto operator()(C pred, P proj = P{}) const
0042             {
0043                 return make_action_closure(
0044                     bind_back(unique_fn{}, std::move(pred), std::move(proj)));
0045             }
0046
0047             template(typename Rng, typename C = equal_to, typename P = identity)(
0048                 requires forward_range<Rng> AND
0049                     erasable_range<Rng &, iterator_t<Rng>, sentinel_t<Rng>> AND
0050                     sortable<iterator_t<Rng>, C, P>)
0051             Rng operator()(Rng && rng, C pred = C{}, P proj = P{}) const
0052             {
0053                 auto it = ranges::unique(rng, std::move(pred), std::move(proj));
0054                 ranges::erase(rng, it, end(rng));
0055                 return static_cast<Rng &&>(rng);
0056             }
0057         };
0058
0059         /// \relates detail::unique_fn
0060         /// \sa action_closure
0061         RANGES_INLINE_VARIABLE(action_closure<unique_fn>, unique)
0062     } // namespace actions
0063     /// @}
0064 } // namespace ranges
0065
0066 #include <range/v3/detail/epilogue.hpp>
0067
0068 #endif