// -*- C++ -*- //===----------------------------------------------------------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// #ifndef _LIBCPP___RANGES_COUNTED_H #define _LIBCPP___RANGES_COUNTED_H #include <__concepts/convertible_to.h> #include <__config> #include <__iterator/concepts.h> #include <__iterator/counted_iterator.h> #include <__iterator/default_sentinel.h> #include <__iterator/incrementable_traits.h> #include <__iterator/iterator_traits.h> #include <__memory/pointer_traits.h> #include <__ranges/subrange.h> #include <__type_traits/decay.h> #include <__utility/forward.h> #include <__utility/move.h> #include #include #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) # pragma GCC system_header #endif _LIBCPP_BEGIN_NAMESPACE_STD #if _LIBCPP_STD_VER >= 20 namespace ranges::views { namespace __counted { struct __fn { template _LIBCPP_HIDE_FROM_ABI static constexpr auto __go(_It __it, iter_difference_t<_It> __count) noexcept(noexcept(span(std::to_address(__it), static_cast(__count)))) // Deliberately omit return-type SFINAE, because to_address is not SFINAE-friendly { return span(std::to_address(__it), static_cast(__count)); } template _LIBCPP_HIDE_FROM_ABI static constexpr auto __go(_It __it, iter_difference_t<_It> __count) noexcept(noexcept(subrange(__it, __it + __count))) -> decltype(subrange(__it, __it + __count)) { return subrange(__it, __it + __count); } template _LIBCPP_HIDE_FROM_ABI static constexpr auto __go(_It __it, iter_difference_t<_It> __count) noexcept( noexcept(subrange(counted_iterator(std::move(__it), __count), default_sentinel))) -> decltype(subrange(counted_iterator(std::move(__it), __count), default_sentinel)) { return subrange(counted_iterator(std::move(__it), __count), default_sentinel); } template > _Diff> requires input_or_output_iterator> [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_It&& __it, _Diff&& __count) const noexcept(noexcept(__go(std::forward<_It>(__it), std::forward<_Diff>(__count)))) -> decltype(__go(std::forward<_It>(__it), std::forward<_Diff>(__count))) { return __go(std::forward<_It>(__it), std::forward<_Diff>(__count)); } }; } // namespace __counted inline namespace __cpo { inline constexpr auto counted = __counted::__fn{}; } // namespace __cpo } // namespace ranges::views #endif // _LIBCPP_STD_VER >= 20 _LIBCPP_END_NAMESPACE_STD #endif // _LIBCPP___RANGES_COUNTED_H