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1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef _LIBCPP___LIBCXX_DEBUG_STRICT_WEAK_ORDERING_CHECK10#define _LIBCPP___LIBCXX_DEBUG_STRICT_WEAK_ORDERING_CHECK11 12#include <__config>13 14#include <__algorithm/comp_ref_type.h>15#include <__algorithm/is_sorted.h>16#include <__assert>17#include <__iterator/iterator_traits.h>18#include <__type_traits/is_constant_evaluated.h>19 20#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)21# pragma GCC system_header22#endif23 24_LIBCPP_BEGIN_NAMESPACE_STD25 26template <class _RandomAccessIterator, class _Comp>27_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void28__check_strict_weak_ordering_sorted(_RandomAccessIterator __first, _RandomAccessIterator __last, _Comp& __comp) {29#if _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_DEBUG30 using __diff_t = __iterator_difference_type<_RandomAccessIterator>;31 using _Comp_ref = __comp_ref_type<_Comp>;32 if (!__libcpp_is_constant_evaluated()) {33 // Check if the range is actually sorted.34 _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(35 (std::is_sorted<_RandomAccessIterator, _Comp_ref>(__first, __last, _Comp_ref(__comp))),36 "The range is not sorted after the sort, your comparator is not a valid strict-weak ordering");37 // Limit the number of elements we need to check.38 __diff_t __size = __last - __first > __diff_t(100) ? __diff_t(100) : __last - __first;39 __diff_t __p = 0;40 while (__p < __size) {41 __diff_t __q = __p + __diff_t(1);42 // Find first element that is greater than *(__first+__p).43 while (__q < __size && !__comp(*(__first + __p), *(__first + __q))) {44 ++__q;45 }46 // Check that the elements from __p to __q are equal between each other.47 for (__diff_t __b = __p; __b < __q; ++__b) {48 for (__diff_t __a = __p; __a <= __b; ++__a) {49 _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(50 !__comp(*(__first + __a), *(__first + __b)), "Your comparator is not a valid strict-weak ordering");51 _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(52 !__comp(*(__first + __b), *(__first + __a)), "Your comparator is not a valid strict-weak ordering");53 }54 }55 // Check that elements between __p and __q are less than between __q and __size.56 for (__diff_t __a = __p; __a < __q; ++__a) {57 for (__diff_t __b = __q; __b < __size; ++__b) {58 _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(59 __comp(*(__first + __a), *(__first + __b)), "Your comparator is not a valid strict-weak ordering");60 _LIBCPP_ASSERT_SEMANTIC_REQUIREMENT(61 !__comp(*(__first + __b), *(__first + __a)), "Your comparator is not a valid strict-weak ordering");62 }63 }64 // Skip these equal elements.65 __p = __q;66 }67 }68#else69 (void)__first;70 (void)__last;71 (void)__comp;72#endif // _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_DEBUG73}74 75_LIBCPP_END_NAMESPACE_STD76 77#endif // _LIBCPP___LIBCXX_DEBUG_STRICT_WEAK_ORDERING_CHECK78