1349cc55cSDimitry Andric // -*- C++ -*- 2349cc55cSDimitry Andric //===----------------------------------------------------------------------===// 3349cc55cSDimitry Andric // 4349cc55cSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5349cc55cSDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 6349cc55cSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7349cc55cSDimitry Andric // 8349cc55cSDimitry Andric //===----------------------------------------------------------------------===// 9bdd1243dSDimitry Andric 10349cc55cSDimitry Andric #ifndef _LIBCPP___RANGES_COUNTED_H 11349cc55cSDimitry Andric #define _LIBCPP___RANGES_COUNTED_H 12349cc55cSDimitry Andric 130eae32dcSDimitry Andric #include <__concepts/convertible_to.h> 14349cc55cSDimitry Andric #include <__config> 15349cc55cSDimitry Andric #include <__iterator/concepts.h> 16349cc55cSDimitry Andric #include <__iterator/counted_iterator.h> 17349cc55cSDimitry Andric #include <__iterator/default_sentinel.h> 18349cc55cSDimitry Andric #include <__iterator/incrementable_traits.h> 19349cc55cSDimitry Andric #include <__iterator/iterator_traits.h> 20349cc55cSDimitry Andric #include <__memory/pointer_traits.h> 21349cc55cSDimitry Andric #include <__ranges/subrange.h> 2206c3fb27SDimitry Andric #include <__type_traits/decay.h> 23349cc55cSDimitry Andric #include <__utility/forward.h> 24349cc55cSDimitry Andric #include <__utility/move.h> 2506c3fb27SDimitry Andric #include <cstddef> 26349cc55cSDimitry Andric #include <span> 27349cc55cSDimitry Andric 28349cc55cSDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 29349cc55cSDimitry Andric # pragma GCC system_header 30349cc55cSDimitry Andric #endif 31349cc55cSDimitry Andric 32b3edf446SDimitry Andric _LIBCPP_PUSH_MACROS 33b3edf446SDimitry Andric #include <__undef_macros> 34b3edf446SDimitry Andric 35349cc55cSDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 36349cc55cSDimitry Andric 3706c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20 38349cc55cSDimitry Andric 39349cc55cSDimitry Andric namespace ranges::views { 40349cc55cSDimitry Andric 41349cc55cSDimitry Andric namespace __counted { 42349cc55cSDimitry Andric 43349cc55cSDimitry Andric struct __fn { 440eae32dcSDimitry Andric template <contiguous_iterator _It> 45cb14a3feSDimitry Andric _LIBCPP_HIDE_FROM_ABI static constexpr auto __go__fn46cb14a3feSDimitry Andric __go(_It __it, 47cb14a3feSDimitry Andric iter_difference_t<_It> __count) noexcept(noexcept(span(std::to_address(__it), static_cast<size_t>(__count)))) 480eae32dcSDimitry Andric // Deliberately omit return-type SFINAE, because to_address is not SFINAE-friendly 49cb14a3feSDimitry Andric { 50cb14a3feSDimitry Andric return span(std::to_address(__it), static_cast<size_t>(__count)); 51cb14a3feSDimitry Andric } 52349cc55cSDimitry Andric 530eae32dcSDimitry Andric template <random_access_iterator _It> 54*0fca6ea1SDimitry Andric _LIBCPP_HIDE_FROM_ABI static constexpr auto __go(_It __it, iter_difference_t<_It> __count) noexcept( 55*0fca6ea1SDimitry Andric noexcept(subrange(__it, __it + __count))) -> decltype(subrange(__it, __it + __count)) { 56cb14a3feSDimitry Andric return subrange(__it, __it + __count); 57cb14a3feSDimitry Andric } 58349cc55cSDimitry Andric 590eae32dcSDimitry Andric template <class _It> 60cb14a3feSDimitry Andric _LIBCPP_HIDE_FROM_ABI static constexpr auto __go(_It __it, iter_difference_t<_It> __count) noexcept( 61cb14a3feSDimitry Andric noexcept(subrange(counted_iterator(std::move(__it), __count), default_sentinel))) 62cb14a3feSDimitry Andric -> decltype(subrange(counted_iterator(std::move(__it), __count), default_sentinel)) { 63cb14a3feSDimitry Andric return subrange(counted_iterator(std::move(__it), __count), default_sentinel); 64cb14a3feSDimitry Andric } 650eae32dcSDimitry Andric 660eae32dcSDimitry Andric template <class _It, convertible_to<iter_difference_t<_It>> _Diff> 670eae32dcSDimitry Andric requires input_or_output_iterator<decay_t<_It>> 68cb14a3feSDimitry Andric [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_It&& __it, _Diff&& __count) const 6981ad6265SDimitry Andric noexcept(noexcept(__go(std::forward<_It>(__it), std::forward<_Diff>(__count)))) 70cb14a3feSDimitry Andric -> decltype(__go(std::forward<_It>(__it), std::forward<_Diff>(__count))) { 71cb14a3feSDimitry Andric return __go(std::forward<_It>(__it), std::forward<_Diff>(__count)); 72cb14a3feSDimitry Andric } 73349cc55cSDimitry Andric }; 740eae32dcSDimitry Andric 750eae32dcSDimitry Andric } // namespace __counted 76349cc55cSDimitry Andric 77349cc55cSDimitry Andric inline namespace __cpo { 78349cc55cSDimitry Andric inline constexpr auto counted = __counted::__fn{}; 79349cc55cSDimitry Andric } // namespace __cpo 80349cc55cSDimitry Andric 81349cc55cSDimitry Andric } // namespace ranges::views 82349cc55cSDimitry Andric 8306c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20 84349cc55cSDimitry Andric 85349cc55cSDimitry Andric _LIBCPP_END_NAMESPACE_STD 86349cc55cSDimitry Andric 87b3edf446SDimitry Andric _LIBCPP_POP_MACROS 88b3edf446SDimitry Andric 89349cc55cSDimitry Andric #endif // _LIBCPP___RANGES_COUNTED_H 90