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- /// \file
- // Range v3 library
- //
- // Copyright Eric Niebler 2013-present
- //
- // Use, modification and distribution is subject to the
- // Boost Software License, Version 1.0. (See accompanying
- // file LICENSE_1_0.txt or copy at
- // http://www.boost.org/LICENSE_1_0.txt)
- //
- // Project home: https://github.com/ericniebler/range-v3
- //
- #ifndef RANGES_V3_VIEW_TAKE_WHILE_HPP
- #define RANGES_V3_VIEW_TAKE_WHILE_HPP
- #include <type_traits>
- #include <utility>
- #include <meta/meta.hpp>
- #include <range/v3/range_fwd.hpp>
- #include <range/v3/functional/bind_back.hpp>
- #include <range/v3/functional/compose.hpp>
- #include <range/v3/functional/indirect.hpp>
- #include <range/v3/functional/invoke.hpp>
- #include <range/v3/iterator/concepts.hpp>
- #include <range/v3/range/concepts.hpp>
- #include <range/v3/utility/semiregular_box.hpp>
- #include <range/v3/utility/static_const.hpp>
- #include <range/v3/view/adaptor.hpp>
- #include <range/v3/view/view.hpp>
- #include <range/v3/detail/prologue.hpp>
- namespace ranges
- {
- /// \addtogroup group-views
- /// @{
- template<typename Rng, typename Pred>
- struct iter_take_while_view
- : view_adaptor<iter_take_while_view<Rng, Pred>, Rng,
- is_finite<Rng>::value ? finite : unknown>
- {
- private:
- friend range_access;
- RANGES_NO_UNIQUE_ADDRESS semiregular_box_t<Pred> pred_;
- template<bool IsConst>
- struct sentinel_adaptor : adaptor_base
- {
- private:
- friend struct sentinel_adaptor<!IsConst>;
- using CRng = meta::const_if_c<IsConst, Rng>;
- RANGES_NO_UNIQUE_ADDRESS semiregular_box_ref_or_val_t<Pred, IsConst> pred_;
- public:
- sentinel_adaptor() = default;
- sentinel_adaptor(semiregular_box_ref_or_val_t<Pred, IsConst> pred)
- : pred_(std::move(pred))
- {}
- template(bool Other)(
- requires IsConst AND CPP_NOT(Other)) //
- sentinel_adaptor(sentinel_adaptor<Other> that)
- : pred_(std::move(that.pred_))
- {}
- bool empty(iterator_t<CRng> const & it, sentinel_t<CRng> const & last) const
- {
- return it == last || !invoke(pred_, it);
- }
- };
- sentinel_adaptor<false> end_adaptor()
- {
- return {pred_};
- }
- template(bool Const = true)(
- requires Const AND range<meta::const_if_c<Const, Rng>> AND
- invocable<Pred const &, iterator_t<meta::const_if_c<Const, Rng>>>)
- sentinel_adaptor<Const> end_adaptor() const
- {
- return {pred_};
- }
- public:
- iter_take_while_view() = default;
- constexpr iter_take_while_view(Rng rng, Pred pred)
- : iter_take_while_view::view_adaptor{std::move(rng)}
- , pred_(std::move(pred))
- {}
- };
- template<typename Rng, typename Pred>
- struct take_while_view : iter_take_while_view<Rng, indirected<Pred>>
- {
- take_while_view() = default;
- constexpr take_while_view(Rng rng, Pred pred)
- : iter_take_while_view<Rng, indirected<Pred>>{std::move(rng),
- indirect(std::move(pred))}
- {}
- };
- #if RANGES_CXX_DEDUCTION_GUIDES >= RANGES_CXX_DEDUCTION_GUIDES_17
- template(typename Rng, typename Fun)(
- requires copy_constructible<Fun>)
- take_while_view(Rng &&, Fun)
- -> take_while_view<views::all_t<Rng>, Fun>;
- #endif
- namespace views
- {
- struct iter_take_while_base_fn
- {
- template(typename Rng, typename Pred)(
- requires viewable_range<Rng> AND input_range<Rng> AND
- predicate<Pred &, iterator_t<Rng>> AND copy_constructible<Pred>)
- constexpr iter_take_while_view<all_t<Rng>, Pred> //
- operator()(Rng && rng, Pred pred) const
- {
- return {all(static_cast<Rng &&>(rng)), std::move(pred)};
- }
- };
- struct iter_take_while_fn : iter_take_while_base_fn
- {
- using iter_take_while_base_fn::operator();
- template<typename Pred>
- constexpr auto operator()(Pred pred) const
- {
- return make_view_closure(
- bind_back(iter_take_while_base_fn{}, std::move(pred)));
- }
- };
- struct take_while_base_fn
- {
- template(typename Rng, typename Pred)(
- requires viewable_range<Rng> AND input_range<Rng> AND
- indirect_unary_predicate<Pred &, iterator_t<Rng>>)
- constexpr take_while_view<all_t<Rng>, Pred> //
- operator()(Rng && rng, Pred pred) const
- {
- return {all(static_cast<Rng &&>(rng)), std::move(pred)};
- }
- template(typename Rng, typename Pred, typename Proj)(
- requires viewable_range<Rng> AND input_range<Rng> AND
- indirect_unary_predicate<composed<Pred, Proj> &, iterator_t<Rng>>)
- constexpr take_while_view<all_t<Rng>, composed<Pred, Proj>> //
- operator()(Rng && rng, Pred pred, Proj proj) const
- {
- return {all(static_cast<Rng &&>(rng)),
- compose(std::move(pred), std::move(proj))};
- }
- };
- struct take_while_bind_fn
- {
- template<typename Pred>
- constexpr auto operator()(Pred pred) const // TODO: underconstrained
- {
- return make_view_closure(
- bind_back(take_while_base_fn{}, std::move(pred)));
- }
- template(typename Pred, typename Proj)(
- requires (!range<Pred>)) // TODO: underconstrained
- constexpr auto operator()(Pred && pred, Proj proj) const
-
- {
- return make_view_closure(bind_back(
- take_while_base_fn{}, static_cast<Pred &&>(pred), std::move(proj)));
- }
- };
- struct RANGES_EMPTY_BASES take_while_fn
- : take_while_base_fn, take_while_bind_fn
- {
- using take_while_base_fn::operator();
- using take_while_bind_fn::operator();
- };
- /// \relates iter_take_while_fn
- /// \ingroup group-views
- RANGES_INLINE_VARIABLE(iter_take_while_fn, iter_take_while)
- /// \relates take_while_fn
- /// \ingroup group-views
- RANGES_INLINE_VARIABLE(take_while_fn, take_while)
- } // namespace views
- namespace cpp20
- {
- namespace views
- {
- using ranges::views::take_while;
- }
- template(typename Rng, typename Pred)(
- requires viewable_range<Rng> AND input_range<Rng> AND
- predicate<Pred &, iterator_t<Rng>> AND copy_constructible<Pred>)
- using take_while_view = ranges::take_while_view<Rng, Pred>;
- } // namespace cpp20
- /// @}
- } // namespace ranges
- #include <range/v3/detail/epilogue.hpp>
- #include <range/v3/detail/satisfy_boost_range.hpp>
- RANGES_SATISFY_BOOST_RANGE(::ranges::iter_take_while_view)
- RANGES_SATISFY_BOOST_RANGE(::ranges::take_while_view)
- #endif
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