| // -*- 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 <cstddef> |
| #include <span> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_PUSH_MACROS |
| #include <__undef_macros> |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| #if _LIBCPP_STD_VER >= 20 |
| |
| namespace ranges::views { |
| |
| namespace __counted { |
| |
| struct __fn { |
| template <contiguous_iterator _It> |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto |
| __go(_It __it, |
| iter_difference_t<_It> __count) noexcept(noexcept(span(std::to_address(__it), static_cast<size_t>(__count)))) |
| // Deliberately omit return-type SFINAE, because to_address is not SFINAE-friendly |
| { |
| return span(std::to_address(__it), static_cast<size_t>(__count)); |
| } |
| |
| template <random_access_iterator _It> |
| _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 <class _It> |
| _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 <class _It, convertible_to<iter_difference_t<_It>> _Diff> |
| requires input_or_output_iterator<decay_t<_It>> |
| [[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 |
| |
| _LIBCPP_POP_MACROS |
| |
| #endif // _LIBCPP___RANGES_COUNTED_H |