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// Core algorithmic facilities -*- C++ -*- |
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|
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// Copyright (C) 2020-2021 Free Software Foundation, Inc. |
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// |
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// This file is part of the GNU ISO C++ Library. This library is free |
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// software; you can redistribute it and/or modify it under the |
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// terms of the GNU General Public License as published by the |
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// Free Software Foundation; either version 3, or (at your option) |
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// any later version. |
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|
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// This library is distributed in the hope that it will be useful, |
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// but WITHOUT ANY WARRANTY; without even the implied warranty of |
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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// GNU General Public License for more details. |
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|
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// Under Section 7 of GPL version 3, you are granted additional |
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// permissions described in the GCC Runtime Library Exception, version |
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// 3.1, as published by the Free Software Foundation. |
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|
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// You should have received a copy of the GNU General Public License and |
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// a copy of the GCC Runtime Library Exception along with this program; |
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
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// <http://www.gnu.org/licenses/>. |
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|
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/** @file bits/ranges_algobase.h |
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* This is an internal header file, included by other library headers. |
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* Do not attempt to use it directly. @headername{algorithm} |
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*/ |
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|
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#ifndef _RANGES_ALGOBASE_H |
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#define _RANGES_ALGOBASE_H 1 |
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|
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#if __cplusplus > 201703L |
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|
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#include <compare> |
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#include <iterator> |
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#include <bits/ranges_base.h> // ranges::begin, ranges::range etc. |
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#include <bits/invoke.h> // __invoke |
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#include <bits/cpp_type_traits.h> // __is_byte |
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|
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#if __cpp_lib_concepts |
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namespace std _GLIBCXX_VISIBILITY(default) |
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{ |
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_GLIBCXX_BEGIN_NAMESPACE_VERSION |
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namespace ranges |
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{ |
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namespace __detail |
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{ |
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template<typename _Tp> |
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constexpr inline bool __is_normal_iterator = false; |
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|
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template<typename _Iterator, typename _Container> |
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constexpr inline bool |
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__is_normal_iterator<__gnu_cxx::__normal_iterator<_Iterator, |
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_Container>> = true; |
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|
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template<typename _Tp> |
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constexpr inline bool __is_reverse_iterator = false; |
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|
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template<typename _Iterator> |
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constexpr inline bool |
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__is_reverse_iterator<reverse_iterator<_Iterator>> = true; |
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|
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template<typename _Tp> |
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constexpr inline bool __is_move_iterator = false; |
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|
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template<typename _Iterator> |
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constexpr inline bool |
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__is_move_iterator<move_iterator<_Iterator>> = true; |
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} // namespace __detail |
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|
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struct __equal_fn |
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{ |
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template<input_iterator _Iter1, sentinel_for<_Iter1> _Sent1, |
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input_iterator _Iter2, sentinel_for<_Iter2> _Sent2, |
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typename _Pred = ranges::equal_to, |
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typename _Proj1 = identity, typename _Proj2 = identity> |
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requires indirectly_comparable<_Iter1, _Iter2, _Pred, _Proj1, _Proj2> |
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constexpr bool |
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operator()(_Iter1 __first1, _Sent1 __last1, |
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_Iter2 __first2, _Sent2 __last2, _Pred __pred = {}, |
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_Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const |
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{ |
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// TODO: implement more specializations to at least have parity with |
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// std::equal. |
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if constexpr (__detail::__is_normal_iterator<_Iter1> |
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&& same_as<_Iter1, _Sent1>) |
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return (*this)(__first1.base(), __last1.base(), |
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std::move(__first2), std::move(__last2), |
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std::move(__pred), |
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std::move(__proj1), std::move(__proj2)); |
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else if constexpr (__detail::__is_normal_iterator<_Iter2> |
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&& same_as<_Iter2, _Sent2>) |
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return (*this)(std::move(__first1), std::move(__last1), |
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__first2.base(), __last2.base(), |
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std::move(__pred), |
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std::move(__proj1), std::move(__proj2)); |
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else if constexpr (sized_sentinel_for<_Sent1, _Iter1> |
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&& sized_sentinel_for<_Sent2, _Iter2>) |
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{ |
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auto __d1 = ranges::distance(__first1, __last1); |
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auto __d2 = ranges::distance(__first2, __last2); |
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if (__d1 != __d2) |
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return false; |
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|
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using _ValueType1 = iter_value_t<_Iter1>; |
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constexpr bool __use_memcmp |
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= ((is_integral_v<_ValueType1> || is_pointer_v<_ValueType1>) |
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&& __memcmpable<_Iter1, _Iter2>::__value |
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&& is_same_v<_Pred, ranges::equal_to> |
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&& is_same_v<_Proj1, identity> |
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&& is_same_v<_Proj2, identity>); |
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if constexpr (__use_memcmp) |
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{ |
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if (const size_t __len = (__last1 - __first1)) |
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return !std::__memcmp(__first1, __first2, __len); |
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return true; |
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} |
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else |
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{ |
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for (; __first1 != __last1; ++__first1, (void)++__first2) |
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if (!(bool)std::__invoke(__pred, |
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std::__invoke(__proj1, *__first1), |
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std::__invoke(__proj2, *__first2))) |
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return false; |
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return true; |
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} |
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} |
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else |
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{ |
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for (; __first1 != __last1 && __first2 != __last2; |
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++__first1, (void)++__first2) |
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if (!(bool)std::__invoke(__pred, |
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std::__invoke(__proj1, *__first1), |
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std::__invoke(__proj2, *__first2))) |
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return false; |
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return __first1 == __last1 && __first2 == __last2; |
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} |
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} |
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|
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template<input_range _Range1, input_range _Range2, |
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typename _Pred = ranges::equal_to, |
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typename _Proj1 = identity, typename _Proj2 = identity> |
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requires indirectly_comparable<iterator_t<_Range1>, iterator_t<_Range2>, |
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_Pred, _Proj1, _Proj2> |
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constexpr bool |
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operator()(_Range1&& __r1, _Range2&& __r2, _Pred __pred = {}, |
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_Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const |
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{ |
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return (*this)(ranges::begin(__r1), ranges::end(__r1), |
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ranges::begin(__r2), ranges::end(__r2), |
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std::move(__pred), |
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std::move(__proj1), std::move(__proj2)); |
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} |
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}; |
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|
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inline constexpr __equal_fn equal{}; |
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|
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template<typename _Iter, typename _Out> |
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struct in_out_result |
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{ |
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[[no_unique_address]] _Iter in; |
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[[no_unique_address]] _Out out; |
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|
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template<typename _Iter2, typename _Out2> |
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requires convertible_to<const _Iter&, _Iter2> |
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&& convertible_to<const _Out&, _Out2> |
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constexpr |
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operator in_out_result<_Iter2, _Out2>() const & |
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{ return {in, out}; } |
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|
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template<typename _Iter2, typename _Out2> |
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requires convertible_to<_Iter, _Iter2> |
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&& convertible_to<_Out, _Out2> |
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constexpr |
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operator in_out_result<_Iter2, _Out2>() && |
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{ return {std::move(in), std::move(out)}; } |
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}; |
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|
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template<typename _Iter, typename _Out> |
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using copy_result = in_out_result<_Iter, _Out>; |
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|
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template<typename _Iter, typename _Out> |
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using move_result = in_out_result<_Iter, _Out>; |
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|
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template<typename _Iter1, typename _Iter2> |
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using move_backward_result = in_out_result<_Iter1, _Iter2>; |
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|
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template<typename _Iter1, typename _Iter2> |
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using copy_backward_result = in_out_result<_Iter1, _Iter2>; |
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|
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template<bool _IsMove, |
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bidirectional_iterator _Iter, sentinel_for<_Iter> _Sent, |
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bidirectional_iterator _Out> |
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requires (_IsMove |
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? indirectly_movable<_Iter, _Out> |
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: indirectly_copyable<_Iter, _Out>) |
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constexpr conditional_t<_IsMove, |
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move_backward_result<_Iter, _Out>, |
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copy_backward_result<_Iter, _Out>> |
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__copy_or_move_backward(_Iter __first, _Sent __last, _Out __result); |
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|
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template<bool _IsMove, |
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input_iterator _Iter, sentinel_for<_Iter> _Sent, |
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weakly_incrementable _Out> |
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requires (_IsMove |
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? indirectly_movable<_Iter, _Out> |
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: indirectly_copyable<_Iter, _Out>) |
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constexpr conditional_t<_IsMove, |
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move_result<_Iter, _Out>, |
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copy_result<_Iter, _Out>> |
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__copy_or_move(_Iter __first, _Sent __last, _Out __result) |
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{ |
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// TODO: implement more specializations to be at least on par with |
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// std::copy/std::move. |
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using __detail::__is_move_iterator; |
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using __detail::__is_reverse_iterator; |
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using __detail::__is_normal_iterator; |
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if constexpr (__is_move_iterator<_Iter> && same_as<_Iter, _Sent>) |
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{ |
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auto [__in, __out] |
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= ranges::__copy_or_move<true>(std::move(__first).base(), |
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std::move(__last).base(), |
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std::move(__result)); |
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return {move_iterator{std::move(__in)}, std::move(__out)}; |
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} |
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else if constexpr (__is_reverse_iterator<_Iter> && same_as<_Iter, _Sent> |
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&& __is_reverse_iterator<_Out>) |
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{ |
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auto [__in,__out] |
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= ranges::__copy_or_move_backward<_IsMove>(std::move(__last).base(), |
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std::move(__first).base(), |
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std::move(__result).base()); |
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return {reverse_iterator{std::move(__in)}, |
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reverse_iterator{std::move(__out)}}; |
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} |
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else if constexpr (__is_normal_iterator<_Iter> && same_as<_Iter, _Sent>) |
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{ |
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auto [__in,__out] |
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= ranges::__copy_or_move<_IsMove>(__first.base(), __last.base(), |
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__result); |
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return {decltype(__first){__in}, std::move(__out)}; |
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} |
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else if constexpr (__is_normal_iterator<_Out>) |
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{ |
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auto [__in,__out] |
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= ranges::__copy_or_move<_IsMove>(__first, __last, __result.base()); |
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return {std::move(__in), decltype(__result){__out}}; |
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} |
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else if constexpr (sized_sentinel_for<_Sent, _Iter>) |
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{ |
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#ifdef __cpp_lib_is_constant_evaluated |
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if (!std::is_constant_evaluated()) |
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#endif |
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{ |
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if constexpr (__memcpyable<_Iter, _Out>::__value) |
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{ |
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using _ValueTypeI = iter_value_t<_Iter>; |
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static_assert(_IsMove |
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? is_move_assignable_v<_ValueTypeI> |
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: is_copy_assignable_v<_ValueTypeI>); |
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auto __num = __last - __first; |
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if (__num) |
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__builtin_memmove(__result, __first, |
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sizeof(_ValueTypeI) * __num); |
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return {__first + __num, __result + __num}; |
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} |
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} |
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|
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for (auto __n = __last - __first; __n > 0; --__n) |
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{ |
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if constexpr (_IsMove) |
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*__result = std::move(*__first); |
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else |
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*__result = *__first; |
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++__first; |
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++__result; |
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} |
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return {std::move(__first), std::move(__result)}; |
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} |
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else |
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{ |
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while (__first != __last) |
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{ |
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if constexpr (_IsMove) |
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*__result = std::move(*__first); |
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else |
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*__result = *__first; |
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++__first; |
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++__result; |
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} |
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return {std::move(__first), std::move(__result)}; |
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} |
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} |
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|
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struct __copy_fn |
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{ |
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template<input_iterator _Iter, sentinel_for<_Iter> _Sent, |
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weakly_incrementable _Out> |
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requires indirectly_copyable<_Iter, _Out> |
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constexpr copy_result<_Iter, _Out> |
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operator()(_Iter __first, _Sent __last, _Out __result) const |
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{ |
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return ranges::__copy_or_move<false>(std::move(__first), |
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std::move(__last), |
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std::move(__result)); |
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} |
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|
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template<input_range _Range, weakly_incrementable _Out> |
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requires indirectly_copyable<iterator_t<_Range>, _Out> |
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constexpr copy_result<borrowed_iterator_t<_Range>, _Out> |
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operator()(_Range&& __r, _Out __result) const |
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{ |
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return (*this)(ranges::begin(__r), ranges::end(__r), |
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std::move(__result)); |
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} |
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}; |
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|
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inline constexpr __copy_fn copy{}; |
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|
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struct __move_fn |
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{ |
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template<input_iterator _Iter, sentinel_for<_Iter> _Sent, |
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weakly_incrementable _Out> |
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requires indirectly_movable<_Iter, _Out> |
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constexpr move_result<_Iter, _Out> |
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operator()(_Iter __first, _Sent __last, _Out __result) const |
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{ |
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return ranges::__copy_or_move<true>(std::move(__first), |
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std::move(__last), |
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std::move(__result)); |
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} |
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|
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template<input_range _Range, weakly_incrementable _Out> |
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requires indirectly_movable<iterator_t<_Range>, _Out> |
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constexpr move_result<borrowed_iterator_t<_Range>, _Out> |
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operator()(_Range&& __r, _Out __result) const |
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{ |
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return (*this)(ranges::begin(__r), ranges::end(__r), |
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std::move(__result)); |
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} |
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}; |
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|
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inline constexpr __move_fn move{}; |
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|
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template<bool _IsMove, |
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bidirectional_iterator _Iter, sentinel_for<_Iter> _Sent, |
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bidirectional_iterator _Out> |
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requires (_IsMove |
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? indirectly_movable<_Iter, _Out> |
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: indirectly_copyable<_Iter, _Out>) |
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constexpr conditional_t<_IsMove, |
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move_backward_result<_Iter, _Out>, |
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copy_backward_result<_Iter, _Out>> |
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__copy_or_move_backward(_Iter __first, _Sent __last, _Out __result) |
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{ |
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// TODO: implement more specializations to be at least on par with |
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// std::copy_backward/std::move_backward. |
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using __detail::__is_reverse_iterator; |
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using __detail::__is_normal_iterator; |
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if constexpr (__is_reverse_iterator<_Iter> && same_as<_Iter, _Sent> |
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&& __is_reverse_iterator<_Out>) |
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{ |
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auto [__in,__out] |
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= ranges::__copy_or_move<_IsMove>(std::move(__last).base(), |
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std::move(__first).base(), |
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std::move(__result).base()); |
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return {reverse_iterator{std::move(__in)}, |
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reverse_iterator{std::move(__out)}}; |
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} |
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else if constexpr (__is_normal_iterator<_Iter> && same_as<_Iter, _Sent>) |
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{ |
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auto [__in,__out] |
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= ranges::__copy_or_move_backward<_IsMove>(__first.base(), |
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__last.base(), |
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std::move(__result)); |
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return {decltype(__first){__in}, std::move(__out)}; |
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} |
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else if constexpr (__is_normal_iterator<_Out>) |
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{ |
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auto [__in,__out] |
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= ranges::__copy_or_move_backward<_IsMove>(std::move(__first), |
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std::move(__last), |
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__result.base()); |
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return {std::move(__in), decltype(__result){__out}}; |
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} |
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else if constexpr (sized_sentinel_for<_Sent, _Iter>) |
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{ |
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#ifdef __cpp_lib_is_constant_evaluated |
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if (!std::is_constant_evaluated()) |
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#endif |
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{ |
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if constexpr (__memcpyable<_Out, _Iter>::__value) |
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{ |
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using _ValueTypeI = iter_value_t<_Iter>; |
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static_assert(_IsMove |
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? is_move_assignable_v<_ValueTypeI> |
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: is_copy_assignable_v<_ValueTypeI>); |
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auto __num = __last - __first; |
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if (__num) |
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__builtin_memmove(__result - __num, __first, |
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sizeof(_ValueTypeI) * __num); |
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return {__first + __num, __result - __num}; |
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} |
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} |
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|
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auto __lasti = ranges::next(__first, __last); |
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auto __tail = __lasti; |
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|
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for (auto __n = __last - __first; __n > 0; --__n) |
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{ |
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--__tail; |
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--__result; |
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if constexpr (_IsMove) |
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*__result = std::move(*__tail); |
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else |
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*__result = *__tail; |
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} |
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return {std::move(__lasti), std::move(__result)}; |
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} |
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else |
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{ |
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auto __lasti = ranges::next(__first, __last); |
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auto __tail = __lasti; |
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|
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while (__first != __tail) |
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{ |
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--__tail; |
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--__result; |
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if constexpr (_IsMove) |
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*__result = std::move(*__tail); |
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else |
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*__result = *__tail; |
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} |
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return {std::move(__lasti), std::move(__result)}; |
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} |
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} |
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|
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struct __copy_backward_fn |
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{ |
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template<bidirectional_iterator _Iter1, sentinel_for<_Iter1> _Sent1, |
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bidirectional_iterator _Iter2> |
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requires indirectly_copyable<_Iter1, _Iter2> |
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constexpr copy_backward_result<_Iter1, _Iter2> |
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operator()(_Iter1 __first, _Sent1 __last, _Iter2 __result) const |
| 446 |
{ |
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return ranges::__copy_or_move_backward<false>(std::move(__first), |
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std::move(__last), |
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std::move(__result)); |
| 450 |
} |
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|
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template<bidirectional_range _Range, bidirectional_iterator _Iter> |
| 453 |
requires indirectly_copyable<iterator_t<_Range>, _Iter> |
| 454 |
constexpr copy_backward_result<borrowed_iterator_t<_Range>, _Iter> |
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operator()(_Range&& __r, _Iter __result) const |
| 456 |
{ |
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return (*this)(ranges::begin(__r), ranges::end(__r), |
| 458 |
std::move(__result)); |
| 459 |
} |
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}; |
| 461 |
|
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inline constexpr __copy_backward_fn copy_backward{}; |
| 463 |
|
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struct __move_backward_fn |
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{ |
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template<bidirectional_iterator _Iter1, sentinel_for<_Iter1> _Sent1, |
| 467 |
bidirectional_iterator _Iter2> |
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requires indirectly_movable<_Iter1, _Iter2> |
| 469 |
constexpr move_backward_result<_Iter1, _Iter2> |
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operator()(_Iter1 __first, _Sent1 __last, _Iter2 __result) const |
| 471 |
{ |
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return ranges::__copy_or_move_backward<true>(std::move(__first), |
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std::move(__last), |
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std::move(__result)); |
| 475 |
} |
| 476 |
|
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template<bidirectional_range _Range, bidirectional_iterator _Iter> |
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requires indirectly_movable<iterator_t<_Range>, _Iter> |
| 479 |
constexpr move_backward_result<borrowed_iterator_t<_Range>, _Iter> |
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operator()(_Range&& __r, _Iter __result) const |
| 481 |
{ |
| 482 |
return (*this)(ranges::begin(__r), ranges::end(__r), |
| 483 |
std::move(__result)); |
| 484 |
} |
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}; |
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|
| 487 |
inline constexpr __move_backward_fn move_backward{}; |
| 488 |
|
| 489 |
template<typename _Iter, typename _Out> |
| 490 |
using copy_n_result = in_out_result<_Iter, _Out>; |
| 491 |
|
| 492 |
struct __copy_n_fn |
| 493 |
{ |
| 494 |
template<input_iterator _Iter, weakly_incrementable _Out> |
| 495 |
requires indirectly_copyable<_Iter, _Out> |
| 496 |
constexpr copy_n_result<_Iter, _Out> |
| 497 |
operator()(_Iter __first, iter_difference_t<_Iter> __n, |
| 498 |
_Out __result) const |
| 499 |
{ |
| 500 |
if constexpr (random_access_iterator<_Iter>) |
| 501 |
{ |
| 502 |
if (__n > 0) |
| 503 |
return ranges::copy(__first, __first + __n, std::move(__result)); |
| 504 |
} |
| 505 |
else |
| 506 |
{ |
| 507 |
for (; __n > 0; --__n, (void)++__result, (void)++__first) |
| 508 |
*__result = *__first; |
| 509 |
} |
| 510 |
return {std::move(__first), std::move(__result)}; |
| 511 |
} |
| 512 |
}; |
| 513 |
|
| 514 |
inline constexpr __copy_n_fn copy_n{}; |
| 515 |
|
| 516 |
struct __fill_n_fn |
| 517 |
{ |
| 518 |
template<typename _Tp, output_iterator<const _Tp&> _Out> |
| 519 |
constexpr _Out |
| 520 |
operator()(_Out __first, iter_difference_t<_Out> __n, |
| 521 |
const _Tp& __value) const |
| 522 |
{ |
| 523 |
// TODO: implement more specializations to be at least on par with |
| 524 |
// std::fill_n |
| 525 |
if (__n <= 0) |
| 526 |
return __first; |
| 527 |
|
| 528 |
// TODO: Generalize this optimization to contiguous iterators. |
| 529 |
if constexpr (is_pointer_v<_Out> |
| 530 |
// Note that __is_byte already implies !is_volatile. |
| 531 |
&& __is_byte<remove_pointer_t<_Out>>::__value |
| 532 |
&& integral<_Tp>) |
| 533 |
{ |
| 534 |
__builtin_memset(__first, static_cast<unsigned char>(__value), __n); |
| 535 |
return __first + __n; |
| 536 |
} |
| 537 |
else if constexpr (is_scalar_v<_Tp>) |
| 538 |
{ |
| 539 |
const auto __tmp = __value; |
| 540 |
for (; __n > 0; --__n, (void)++__first) |
| 541 |
*__first = __tmp; |
| 542 |
return __first; |
| 543 |
} |
| 544 |
else |
| 545 |
{ |
| 546 |
for (; __n > 0; --__n, (void)++__first) |
| 547 |
*__first = __value; |
| 548 |
return __first; |
| 549 |
} |
| 550 |
} |
| 551 |
}; |
| 552 |
|
| 553 |
inline constexpr __fill_n_fn fill_n{}; |
| 554 |
|
| 555 |
struct __fill_fn |
| 556 |
{ |
| 557 |
template<typename _Tp, |
| 558 |
output_iterator<const _Tp&> _Out, sentinel_for<_Out> _Sent> |
| 559 |
constexpr _Out |
| 560 |
operator()(_Out __first, _Sent __last, const _Tp& __value) const |
| 561 |
{ |
| 562 |
// TODO: implement more specializations to be at least on par with |
| 563 |
// std::fill |
| 564 |
if constexpr (sized_sentinel_for<_Sent, _Out>) |
| 565 |
{ |
| 566 |
const auto __len = __last - __first; |
| 567 |
return ranges::fill_n(__first, __len, __value); |
| 568 |
} |
| 569 |
else if constexpr (is_scalar_v<_Tp>) |
| 570 |
{ |
| 571 |
const auto __tmp = __value; |
| 572 |
for (; __first != __last; ++__first) |
| 573 |
*__first = __tmp; |
| 574 |
return __first; |
| 575 |
} |
| 576 |
else |
| 577 |
{ |
| 578 |
for (; __first != __last; ++__first) |
| 579 |
*__first = __value; |
| 580 |
return __first; |
| 581 |
} |
| 582 |
} |
| 583 |
|
| 584 |
template<typename _Tp, output_range<const _Tp&> _Range> |
| 585 |
constexpr borrowed_iterator_t<_Range> |
| 586 |
operator()(_Range&& __r, const _Tp& __value) const |
| 587 |
{ |
| 588 |
return (*this)(ranges::begin(__r), ranges::end(__r), __value); |
| 589 |
} |
| 590 |
}; |
| 591 |
|
| 592 |
inline constexpr __fill_fn fill{}; |
| 593 |
} |
| 594 |
_GLIBCXX_END_NAMESPACE_VERSION |
| 595 |
} // namespace std |
| 596 |
#endif // concepts |
| 597 |
#endif // C++20 |
| 598 |
#endif // _RANGES_ALGOBASE_H |
