176d0caaeSpatrick //===----------------------------------------------------------------------===//
276d0caaeSpatrick //
376d0caaeSpatrick // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
476d0caaeSpatrick // See https://llvm.org/LICENSE.txt for license information.
576d0caaeSpatrick // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
676d0caaeSpatrick //
776d0caaeSpatrick //===----------------------------------------------------------------------===//
876d0caaeSpatrick
976d0caaeSpatrick #ifndef _LIBCPP___ALGORITHM_LOWER_BOUND_H
1076d0caaeSpatrick #define _LIBCPP___ALGORITHM_LOWER_BOUND_H
1176d0caaeSpatrick
1276d0caaeSpatrick #include <__algorithm/comp.h>
1376d0caaeSpatrick #include <__algorithm/half_positive.h>
14*4bdff4beSrobert #include <__algorithm/iterator_operations.h>
15*4bdff4beSrobert #include <__config>
16*4bdff4beSrobert #include <__functional/identity.h>
17*4bdff4beSrobert #include <__functional/invoke.h>
18*4bdff4beSrobert #include <__iterator/advance.h>
19*4bdff4beSrobert #include <__iterator/distance.h>
20*4bdff4beSrobert #include <__iterator/iterator_traits.h>
21*4bdff4beSrobert #include <__type_traits/is_callable.h>
22*4bdff4beSrobert #include <__type_traits/remove_reference.h>
23*4bdff4beSrobert #include <type_traits>
2476d0caaeSpatrick
2576d0caaeSpatrick #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
2676d0caaeSpatrick # pragma GCC system_header
2776d0caaeSpatrick #endif
2876d0caaeSpatrick
2976d0caaeSpatrick _LIBCPP_BEGIN_NAMESPACE_STD
3076d0caaeSpatrick
31*4bdff4beSrobert template <class _AlgPolicy, class _Iter, class _Sent, class _Type, class _Proj, class _Comp>
32*4bdff4beSrobert _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
__lower_bound_impl(_Iter __first,_Sent __last,const _Type & __value,_Comp & __comp,_Proj & __proj)33*4bdff4beSrobert _Iter __lower_bound_impl(_Iter __first, _Sent __last, const _Type& __value, _Comp& __comp, _Proj& __proj) {
34*4bdff4beSrobert auto __len = _IterOps<_AlgPolicy>::distance(__first, __last);
35*4bdff4beSrobert
36*4bdff4beSrobert while (__len != 0) {
37*4bdff4beSrobert auto __l2 = std::__half_positive(__len);
38*4bdff4beSrobert _Iter __m = __first;
39*4bdff4beSrobert _IterOps<_AlgPolicy>::advance(__m, __l2);
40*4bdff4beSrobert if (std::__invoke(__comp, std::__invoke(__proj, *__m), __value)) {
4176d0caaeSpatrick __first = ++__m;
4276d0caaeSpatrick __len -= __l2 + 1;
43*4bdff4beSrobert } else {
4476d0caaeSpatrick __len = __l2;
4576d0caaeSpatrick }
46*4bdff4beSrobert }
4776d0caaeSpatrick return __first;
4876d0caaeSpatrick }
4976d0caaeSpatrick
5076d0caaeSpatrick template <class _ForwardIterator, class _Tp, class _Compare>
51*4bdff4beSrobert _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
lower_bound(_ForwardIterator __first,_ForwardIterator __last,const _Tp & __value,_Compare __comp)52*4bdff4beSrobert _ForwardIterator lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value, _Compare __comp) {
53*4bdff4beSrobert static_assert(__is_callable<_Compare, decltype(*__first), const _Tp&>::value,
54*4bdff4beSrobert "The comparator has to be callable");
55*4bdff4beSrobert auto __proj = std::__identity();
56*4bdff4beSrobert return std::__lower_bound_impl<_ClassicAlgPolicy>(__first, __last, __value, __comp, __proj);
5776d0caaeSpatrick }
5876d0caaeSpatrick
5976d0caaeSpatrick template <class _ForwardIterator, class _Tp>
60*4bdff4beSrobert _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
lower_bound(_ForwardIterator __first,_ForwardIterator __last,const _Tp & __value)61*4bdff4beSrobert _ForwardIterator lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
62*4bdff4beSrobert return std::lower_bound(__first, __last, __value,
6376d0caaeSpatrick __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
6476d0caaeSpatrick }
6576d0caaeSpatrick
6676d0caaeSpatrick _LIBCPP_END_NAMESPACE_STD
6776d0caaeSpatrick
6876d0caaeSpatrick #endif // _LIBCPP___ALGORITHM_LOWER_BOUND_H
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