================ @@ -0,0 +1,118 @@ +// -*- 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___ALGORITHM_FOLD_H +#define _LIBCPP___ALGORITHM_FOLD_H + +#include <__concepts/assignable.h> +#include <__concepts/convertible_to.h> +#include <__concepts/invocable.h> +#include <__concepts/movable.h> +#include <__config> +#include <__functional/invoke.h> +#include <__functional/reference_wrapper.h> +#include <__iterator/concepts.h> +#include <__iterator/iterator_traits.h> +#include <__iterator/next.h> +#include <__ranges/access.h> +#include <__ranges/concepts.h> +#include <__ranges/dangling.h> +#include <__type_traits/decay.h> +#include <__type_traits/invoke.h> +#include <__utility/forward.h> +#include <__utility/move.h> + +#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) +# pragma GCC system_header +#endif + +_LIBCPP_BEGIN_NAMESPACE_STD + +#if _LIBCPP_STD_VER >= 23 + +namespace ranges { +template <class _Ip, class _Tp> +struct in_value_result { + _Ip in; + _Tp result; +}; + +template <class _Ip, class _Tp> +using fold_left_with_iter_result = in_value_result<_Ip, _Tp>; + +template <class _Fp, class _Tp, class _Ip, class _Rp, class _Up = decay_t<_Rp>> +concept __indirectly_binary_left_foldable_impl = + convertible_to<_Rp, _Up> && // + movable<_Tp> && // + movable<_Up> && // + convertible_to<_Tp, _Up> && // + invocable<_Fp&, _Up, iter_reference_t<_Ip>> && // + assignable_from<_Up&, invoke_result_t<_Fp&, _Up, iter_reference_t<_Ip>>>; + +template <class _Fp, class _Tp, class _Ip> +concept __indirectly_binary_left_foldable = + copy_constructible<_Fp> && // + invocable<_Fp&, _Tp, iter_reference_t<_Ip>> && // + __indirectly_binary_left_foldable_impl<_Fp, _Tp, _Ip, invoke_result_t<_Fp&, _Tp, iter_reference_t<_Ip>>>; + +struct __fold_left_with_iter { + template <input_iterator _Ip, sentinel_for<_Ip> _Sp, class _Tp, __indirectly_binary_left_foldable<_Tp, _Ip> _Fp> + _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI static constexpr auto + operator()(_Ip __first, _Sp __last, _Tp __init, _Fp __f) { + using _Up = decay_t<invoke_result_t<_Fp&, _Tp, iter_reference_t<_Ip>>>; + + if (__first == __last) { + return fold_left_with_iter_result<_Ip, _Up>{std::move(__first), _Up(std::move(__init))}; + } + + _Up __result = std::invoke(__f, std::move(__init), *__first); + for (++__first; __first != __last; ++__first) { + __result = std::invoke(__f, std::move(__result), *__first); + } + + return fold_left_with_iter_result<_Ip, _Up>{std::move(__first), std::move(__result)}; + } + + template <input_range _Rp, class _Tp, __indirectly_binary_left_foldable<_Tp, iterator_t<_Rp>> _Fp> + _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI static constexpr auto operator()(_Rp&& __r, _Tp __init, _Fp __f) { + auto __result = operator()(ranges::begin(__r), ranges::end(__r), std::move(__init), std::ref(__f)); + + using _Up = decay_t<invoke_result_t<_Fp&, _Tp, range_reference_t<_Rp>>>; + return fold_left_with_iter_result<borrowed_iterator_t<_Rp>, _Up>{ + std::move(__result.in), std::move(__result.result)}; + } +}; + +inline namespace __cpo { +inline constexpr auto fold_left_with_iter = __fold_left_with_iter(); +} // namespace __cpo + +struct __fold_left { + template <input_iterator _Ip, sentinel_for<_Ip> _Sp, class _Tp, __indirectly_binary_left_foldable<_Tp, _Ip> _Fp> ---------------- cjdb wrote:
See #76540 for the renaming patch. https://github.com/llvm/llvm-project/pull/75259 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
