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1// -*- C++ -*-2//===----------------------------------------------------------------------===//3//4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.5// See https://llvm.org/LICENSE.txt for license information.6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception7//8//===----------------------------------------------------------------------===//9 10#ifndef _LIBCPP___FLAT_SET_UTILS_H11#define _LIBCPP___FLAT_SET_UTILS_H12 13#include <__config>14#include <__iterator/iterator_traits.h>15#include <__ranges/access.h>16#include <__ranges/concepts.h>17#include <__type_traits/container_traits.h>18#include <__type_traits/decay.h>19#include <__utility/exception_guard.h>20#include <__utility/forward.h>21#include <__utility/move.h>22 23#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)24# pragma GCC system_header25#endif26 27_LIBCPP_PUSH_MACROS28#include <__undef_macros>29 30#if _LIBCPP_STD_VER >= 2331 32_LIBCPP_BEGIN_NAMESPACE_STD33 34// These utilities are defined in a class instead of a namespace so that this class can be befriended more easily.35struct __flat_set_utils {36 // Emplace a key into a flat_{multi}set, at the exact position that37 // __it point to, assuming that the key is not already present in the set.38 // When an exception is thrown during the emplacement, the function will clear the set if the container does not39 // have strong exception safety guarantee on emplacement.40 template <class _Set, class _Iter, class _KeyArg>41 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 static auto42 __emplace_exact_pos(_Set& __set, _Iter&& __iter, _KeyArg&& __key) {43 using _KeyContainer = typename decay_t<_Set>::container_type;44 auto __on_failure = std::__make_exception_guard([&]() noexcept {45 if constexpr (!__container_traits<_KeyContainer>::__emplacement_has_strong_exception_safety_guarantee) {46 __set.clear() /* noexcept */;47 }48 });49 auto __key_it = __set.__keys_.emplace(__iter.__base(), std::forward<_KeyArg>(__key));50 __on_failure.__complete();51 return typename decay_t<_Set>::iterator(std::move(__key_it));52 }53 54 template <class _Set, class _InputIterator>55 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 static void56 __append(_Set& __set, _InputIterator __first, _InputIterator __last) {57 __set.__keys_.insert(__set.__keys_.end(), std::move(__first), std::move(__last));58 }59 60 template <class _Set, class _Range>61 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 static void __append(_Set& __set, _Range&& __rng) {62 if constexpr (requires { __set.__keys_.insert_range(__set.__keys_.end(), std::forward<_Range>(__rng)); }) {63 // C++23 Sequence Container should have insert_range member function64 // Note that not all Sequence Containers provide append_range.65 __set.__keys_.insert_range(__set.__keys_.end(), std::forward<_Range>(__rng));66 } else if constexpr (ranges::common_range<_Range> &&67 __has_input_iterator_category<ranges::iterator_t<_Range>>::value) {68 __set.__keys_.insert(__set.__keys_.end(), ranges::begin(__rng), ranges::end(__rng));69 } else {70 for (auto&& __x : __rng) {71 __set.__keys_.insert(__set.__keys_.end(), std::forward<decltype(__x)>(__x));72 }73 }74 }75};76_LIBCPP_END_NAMESPACE_STD77 78#endif // _LIBCPP_STD_VER >= 2379 80_LIBCPP_POP_MACROS81 82#endif // #define _LIBCPP___FLAT_SET_UTILS_H83