v3/view/unbounded.hpp

0001 //
0002 //  Copyright Eric Niebler 2014-present
0003 //
0004 //  Use, modification and distribution is subject to the
0005 //  Boost Software License, Version 1.0. (See accompanying
0006 //  file LICENSE_1_0.txt or copy at
0007 //  http://www.boost.org/LICENSE_1_0.txt)
0008 //
0009 // Project home: https://github.com/ericniebler/range-v3
0010 //
0011
0012 #ifndef RANGES_V3_VIEW_UNBOUNDED_HPP
0013 #define RANGES_V3_VIEW_UNBOUNDED_HPP
0014
0015 #include <range/v3/range_fwd.hpp>
0016
0017 #include <range/v3/iterator/unreachable_sentinel.hpp>
0018 #include <range/v3/utility/static_const.hpp>
0019 #include <range/v3/view/interface.hpp>
0020
0021 #include <range/v3/detail/prologue.hpp>
0022
0023 namespace ranges
0024 {
0025     /// \addtogroup group-views
0026     /// @{
0027     template<typename I>
0028     struct unbounded_view : view_interface<unbounded_view<I>, infinite>
0029     {
0030     private:
0031         I it_;
0032
0033     public:
0034         unbounded_view() = default;
0035         constexpr explicit unbounded_view(I it)
0036           : it_(detail::move(it))
0037         {}
0038         constexpr I begin() const
0039         {
0040             return it_;
0041         }
0042         constexpr unreachable_sentinel_t end() const
0043         {
0044             return {};
0045         }
0046     };
0047
0048     template<typename I>
0049     RANGES_INLINE_VAR constexpr bool enable_borrowed_range<unbounded_view<I>> = true;
0050
0051     namespace views
0052     {
0053         struct unbounded_fn
0054         {
0055             template(typename I)(
0056                 requires input_iterator<I>)
0057             constexpr unbounded_view<I> operator()(I it) const
0058             {
0059                 return unbounded_view<I>{detail::move(it)};
0060             }
0061         };
0062
0063         /// \relates unbounded_fn
0064         /// \ingroup group-views
0065         RANGES_INLINE_VARIABLE(unbounded_fn, unbounded)
0066     } // namespace views
0067     /// @}
0068 } // namespace ranges
0069
0070 #include <range/v3/detail/epilogue.hpp>
0071 #include <range/v3/detail/satisfy_boost_range.hpp>
0072 RANGES_SATISFY_BOOST_RANGE(::ranges::unbounded_view)
0073
0074 #endif