diff options
Diffstat (limited to 'libcxx/include/__ranges/take_view.h')
| -rw-r--r-- | libcxx/include/__ranges/take_view.h | 218 |
1 files changed, 102 insertions, 116 deletions
diff --git a/libcxx/include/__ranges/take_view.h b/libcxx/include/__ranges/take_view.h index 518375d..4fd1d8b 100644 --- a/libcxx/include/__ranges/take_view.h +++ b/libcxx/include/__ranges/take_view.h @@ -57,37 +57,42 @@ _LIBCPP_BEGIN_NAMESPACE_STD namespace ranges { -template<view _View> +template <view _View> class take_view : public view_interface<take_view<_View>> { _LIBCPP_NO_UNIQUE_ADDRESS _View __base_ = _View(); - range_difference_t<_View> __count_ = 0; + range_difference_t<_View> __count_ = 0; - template<bool> class __sentinel; + template <bool> + class __sentinel; public: - _LIBCPP_HIDE_FROM_ABI - take_view() requires default_initializable<_View> = default; + _LIBCPP_HIDE_FROM_ABI take_view() + requires default_initializable<_View> + = default; - _LIBCPP_HIDE_FROM_ABI - constexpr _LIBCPP_EXPLICIT_SINCE_CXX23 take_view(_View __base, range_difference_t<_View> __count) + _LIBCPP_HIDE_FROM_ABI constexpr _LIBCPP_EXPLICIT_SINCE_CXX23 + take_view(_View __base, range_difference_t<_View> __count) : __base_(std::move(__base)), __count_(__count) { _LIBCPP_ASSERT_UNCATEGORIZED(__count >= 0, "count has to be greater than or equal to zero"); } - _LIBCPP_HIDE_FROM_ABI - constexpr _View base() const& requires copy_constructible<_View> { return __base_; } + _LIBCPP_HIDE_FROM_ABI constexpr _View base() const& + requires copy_constructible<_View> + { + return __base_; + } - _LIBCPP_HIDE_FROM_ABI - constexpr _View base() && { return std::move(__base_); } + _LIBCPP_HIDE_FROM_ABI constexpr _View base() && { return std::move(__base_); } - _LIBCPP_HIDE_FROM_ABI - constexpr auto begin() requires (!__simple_view<_View>) { + _LIBCPP_HIDE_FROM_ABI constexpr auto begin() + requires(!__simple_view<_View>) + { if constexpr (sized_range<_View>) { if constexpr (random_access_range<_View>) { return ranges::begin(__base_); } else { using _DifferenceT = range_difference_t<_View>; - auto __size = size(); + auto __size = size(); return counted_iterator(ranges::begin(__base_), static_cast<_DifferenceT>(__size)); } } else { @@ -95,14 +100,15 @@ public: } } - _LIBCPP_HIDE_FROM_ABI - constexpr auto begin() const requires range<const _View> { + _LIBCPP_HIDE_FROM_ABI constexpr auto begin() const + requires range<const _View> + { if constexpr (sized_range<const _View>) { if constexpr (random_access_range<const _View>) { return ranges::begin(__base_); } else { using _DifferenceT = range_difference_t<const _View>; - auto __size = size(); + auto __size = size(); return counted_iterator(ranges::begin(__base_), static_cast<_DifferenceT>(__size)); } } else { @@ -110,8 +116,9 @@ public: } } - _LIBCPP_HIDE_FROM_ABI - constexpr auto end() requires (!__simple_view<_View>) { + _LIBCPP_HIDE_FROM_ABI constexpr auto end() + requires(!__simple_view<_View>) + { if constexpr (sized_range<_View>) { if constexpr (random_access_range<_View>) { return ranges::begin(__base_) + size(); @@ -123,8 +130,9 @@ public: } } - _LIBCPP_HIDE_FROM_ABI - constexpr auto end() const requires range<const _View> { + _LIBCPP_HIDE_FROM_ABI constexpr auto end() const + requires range<const _View> + { if constexpr (sized_range<const _View>) { if constexpr (random_access_range<const _View>) { return ranges::begin(__base_) + size(); @@ -136,47 +144,44 @@ public: } } - _LIBCPP_HIDE_FROM_ABI - constexpr auto size() requires sized_range<_View> { + _LIBCPP_HIDE_FROM_ABI constexpr auto size() + requires sized_range<_View> + { auto __n = ranges::size(__base_); return ranges::min(__n, static_cast<decltype(__n)>(__count_)); } - _LIBCPP_HIDE_FROM_ABI - constexpr auto size() const requires sized_range<const _View> { + _LIBCPP_HIDE_FROM_ABI constexpr auto size() const + requires sized_range<const _View> + { auto __n = ranges::size(__base_); return ranges::min(__n, static_cast<decltype(__n)>(__count_)); } }; -template<view _View> -template<bool _Const> +template <view _View> +template <bool _Const> class take_view<_View>::__sentinel { using _Base = __maybe_const<_Const, _View>; - template<bool _OtherConst> - using _Iter = counted_iterator<iterator_t<__maybe_const<_OtherConst, _View>>>; + template <bool _OtherConst> + using _Iter = counted_iterator<iterator_t<__maybe_const<_OtherConst, _View>>>; _LIBCPP_NO_UNIQUE_ADDRESS sentinel_t<_Base> __end_ = sentinel_t<_Base>(); - template<bool> + template <bool> friend class take_view<_View>::__sentinel; public: - _LIBCPP_HIDE_FROM_ABI - __sentinel() = default; + _LIBCPP_HIDE_FROM_ABI __sentinel() = default; - _LIBCPP_HIDE_FROM_ABI - constexpr explicit __sentinel(sentinel_t<_Base> __end) : __end_(std::move(__end)) {} + _LIBCPP_HIDE_FROM_ABI constexpr explicit __sentinel(sentinel_t<_Base> __end) : __end_(std::move(__end)) {} - _LIBCPP_HIDE_FROM_ABI - constexpr __sentinel(__sentinel<!_Const> __s) + _LIBCPP_HIDE_FROM_ABI constexpr __sentinel(__sentinel<!_Const> __s) requires _Const && convertible_to<sentinel_t<_View>, sentinel_t<_Base>> - : __end_(std::move(__s.__end_)) {} + : __end_(std::move(__s.__end_)) {} - _LIBCPP_HIDE_FROM_ABI - constexpr sentinel_t<_Base> base() const { return __end_; } + _LIBCPP_HIDE_FROM_ABI constexpr sentinel_t<_Base> base() const { return __end_; } - _LIBCPP_HIDE_FROM_ABI - friend constexpr bool operator==(const _Iter<_Const>& __lhs, const __sentinel& __rhs) { + _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const _Iter<_Const>& __lhs, const __sentinel& __rhs) { return __lhs.count() == 0 || __lhs.base() == __rhs.__end_; } @@ -187,10 +192,10 @@ public: } }; -template<class _Range> +template <class _Range> take_view(_Range&&, range_difference_t<_Range>) -> take_view<views::all_t<_Range>>; -template<class _Tp> +template <class _Tp> inline constexpr bool enable_borrowed_range<take_view<_Tp>> = enable_borrowed_range<_Tp>; namespace views { @@ -234,7 +239,7 @@ struct __passthrough_type<basic_string_view<_CharT, _Traits>> { }; template <class _Iter, class _Sent, subrange_kind _Kind> - requires requires{typename subrange<_Iter>;} + requires requires { typename subrange<_Iter>; } struct __passthrough_type<subrange<_Iter, _Sent, _Kind>> { using type = subrange<_Iter>; }; @@ -246,62 +251,48 @@ struct __fn { // [range.take.overview]: the `empty_view` case. template <class _Range, convertible_to<range_difference_t<_Range>> _Np> requires __is_empty_view<remove_cvref_t<_Range>> - [[nodiscard]] _LIBCPP_HIDE_FROM_ABI - constexpr auto operator()(_Range&& __range, _Np&&) const - noexcept(noexcept(_LIBCPP_AUTO_CAST(std::forward<_Range>(__range)))) - -> decltype( _LIBCPP_AUTO_CAST(std::forward<_Range>(__range))) - { return _LIBCPP_AUTO_CAST(std::forward<_Range>(__range)); } + [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Range&& __range, _Np&&) const + noexcept(noexcept(_LIBCPP_AUTO_CAST(std::forward<_Range>(__range)))) + -> decltype(_LIBCPP_AUTO_CAST(std::forward<_Range>(__range))) { + return _LIBCPP_AUTO_CAST(std::forward<_Range>(__range)); + } // [range.take.overview]: the `span | basic_string_view | subrange` case. template <class _Range, convertible_to<range_difference_t<_Range>> _Np, class _RawRange = remove_cvref_t<_Range>, - class _Dist = range_difference_t<_Range>> - requires (!__is_empty_view<_RawRange> && - random_access_range<_RawRange> && - sized_range<_RawRange> && - __is_passthrough_specialization<_RawRange>) - [[nodiscard]] _LIBCPP_HIDE_FROM_ABI - constexpr auto operator()(_Range&& __rng, _Np&& __n) const - noexcept(noexcept(__passthrough_type_t<_RawRange>( - ranges::begin(__rng), - ranges::begin(__rng) + std::min<_Dist>(ranges::distance(__rng), std::forward<_Np>(__n)) - ))) - -> decltype( __passthrough_type_t<_RawRange>( - // Note: deliberately not forwarding `__rng` to guard against double moves. - ranges::begin(__rng), - ranges::begin(__rng) + std::min<_Dist>(ranges::distance(__rng), std::forward<_Np>(__n)) - )) - { return __passthrough_type_t<_RawRange>( - ranges::begin(__rng), - ranges::begin(__rng) + std::min<_Dist>(ranges::distance(__rng), std::forward<_Np>(__n)) - ); } + class _Dist = range_difference_t<_Range>> + requires(!__is_empty_view<_RawRange> && random_access_range<_RawRange> && sized_range<_RawRange> && + __is_passthrough_specialization<_RawRange>) + [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto + operator()(_Range&& __rng, _Np&& __n) const noexcept(noexcept(__passthrough_type_t<_RawRange>( + ranges::begin(__rng), ranges::begin(__rng) + std::min<_Dist>(ranges::distance(__rng), std::forward<_Np>(__n))))) + -> decltype(__passthrough_type_t<_RawRange>( + // Note: deliberately not forwarding `__rng` to guard against double moves. + ranges::begin(__rng), + ranges::begin(__rng) + std::min<_Dist>(ranges::distance(__rng), std::forward<_Np>(__n)))) { + return __passthrough_type_t<_RawRange>( + ranges::begin(__rng), ranges::begin(__rng) + std::min<_Dist>(ranges::distance(__rng), std::forward<_Np>(__n))); + } // [range.take.overview]: the `iota_view` case. template <class _Range, convertible_to<range_difference_t<_Range>> _Np, class _RawRange = remove_cvref_t<_Range>, - class _Dist = range_difference_t<_Range>> - requires (!__is_empty_view<_RawRange> && - random_access_range<_RawRange> && - sized_range<_RawRange> && - __is_iota_specialization<_RawRange>) - [[nodiscard]] _LIBCPP_HIDE_FROM_ABI - constexpr auto operator()(_Range&& __rng, _Np&& __n) const - noexcept(noexcept(ranges::iota_view( - *ranges::begin(__rng), - *ranges::begin(__rng) + std::min<_Dist>(ranges::distance(__rng), std::forward<_Np>(__n)) - ))) - -> decltype( ranges::iota_view( - // Note: deliberately not forwarding `__rng` to guard against double moves. - *ranges::begin(__rng), - *ranges::begin(__rng) + std::min<_Dist>(ranges::distance(__rng), std::forward<_Np>(__n)) - )) - { return ranges::iota_view( - *ranges::begin(__rng), - *ranges::begin(__rng) + std::min<_Dist>(ranges::distance(__rng), std::forward<_Np>(__n)) - ); } -// clang-format off + class _Dist = range_difference_t<_Range>> + requires(!__is_empty_view<_RawRange> && random_access_range<_RawRange> && sized_range<_RawRange> && + __is_iota_specialization<_RawRange>) + [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto + operator()(_Range&& __rng, _Np&& __n) const noexcept(noexcept(ranges::iota_view( + *ranges::begin(__rng), *ranges::begin(__rng) + std::min<_Dist>(ranges::distance(__rng), std::forward<_Np>(__n))))) + -> decltype(ranges::iota_view( + // Note: deliberately not forwarding `__rng` to guard against double moves. + *ranges::begin(__rng), + *ranges::begin(__rng) + std::min<_Dist>(ranges::distance(__rng), std::forward<_Np>(__n)))) { + return ranges::iota_view(*ranges::begin(__rng), + *ranges::begin(__rng) + std::min<_Dist>(ranges::distance(__rng), std::forward<_Np>(__n))); + } + // clang-format off #if _LIBCPP_STD_VER >= 23 // [range.take.overview]: the `repeat_view` "_RawRange models sized_range" case. template <class _Range, @@ -325,42 +316,37 @@ struct __fn { -> decltype( views::repeat(*__range.__value_, static_cast<_Dist>(__n))) { return views::repeat(*__range.__value_, static_cast<_Dist>(__n)); } #endif -// clang-format on + // clang-format on // [range.take.overview]: the "otherwise" case. - template <class _Range, convertible_to<range_difference_t<_Range>> _Np, - class _RawRange = remove_cvref_t<_Range>> - // Note: without specifically excluding the other cases, GCC sees this overload as ambiguous with the other - // overloads. - requires (!(__is_empty_view<_RawRange> || -#if _LIBCPP_STD_VER >= 23 - __is_repeat_specialization<_RawRange> || -#endif - (__is_iota_specialization<_RawRange> && - sized_range<_RawRange> && - random_access_range<_RawRange>) || - (__is_passthrough_specialization<_RawRange> && - sized_range<_RawRange> && - random_access_range<_RawRange>) - )) - [[nodiscard]] _LIBCPP_HIDE_FROM_ABI - constexpr auto operator()(_Range&& __range, _Np&& __n) const - noexcept(noexcept(take_view(std::forward<_Range>(__range), std::forward<_Np>(__n)))) - -> decltype( take_view(std::forward<_Range>(__range), std::forward<_Np>(__n))) - { return take_view(std::forward<_Range>(__range), std::forward<_Np>(__n)); } + template <class _Range, convertible_to<range_difference_t<_Range>> _Np, class _RawRange = remove_cvref_t<_Range>> + // Note: without specifically excluding the other cases, GCC sees this overload as ambiguous with the other + // overloads. + requires(!(__is_empty_view<_RawRange> || +# if _LIBCPP_STD_VER >= 23 + __is_repeat_specialization<_RawRange> || +# endif + (__is_iota_specialization<_RawRange> && sized_range<_RawRange> && random_access_range<_RawRange>) || + (__is_passthrough_specialization<_RawRange> && sized_range<_RawRange> && + random_access_range<_RawRange>))) + [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Range&& __range, _Np&& __n) const + noexcept(noexcept(take_view(std::forward<_Range>(__range), std::forward<_Np>(__n)))) + -> decltype(take_view(std::forward<_Range>(__range), std::forward<_Np>(__n))) { + return take_view(std::forward<_Range>(__range), std::forward<_Np>(__n)); + } template <class _Np> requires constructible_from<decay_t<_Np>, _Np> - [[nodiscard]] _LIBCPP_HIDE_FROM_ABI - constexpr auto operator()(_Np&& __n) const - noexcept(is_nothrow_constructible_v<decay_t<_Np>, _Np>) - { return __range_adaptor_closure_t(std::__bind_back(*this, std::forward<_Np>(__n))); } + [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Np&& __n) const + noexcept(is_nothrow_constructible_v<decay_t<_Np>, _Np>) { + return __range_adaptor_closure_t(std::__bind_back(*this, std::forward<_Np>(__n))); + } }; } // namespace __take inline namespace __cpo { - inline constexpr auto take = __take::__fn{}; +inline constexpr auto take = __take::__fn{}; } // namespace __cpo } // namespace views |