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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___ALGORITHM_RANGES_MIN_ELEMENT_H 10 #define _LIBCPP___ALGORITHM_RANGES_MIN_ELEMENT_H 11 12 #include <__config> 13 #include <__functional/identity.h> 14 #include <__functional/invoke.h> 15 #include <__functional/ranges_operations.h> 16 #include <__iterator/concepts.h> 17 #include <__iterator/projected.h> 18 #include <__ranges/access.h> 19 #include <__ranges/concepts.h> 20 #include <__ranges/dangling.h> 21 #include <__utility/forward.h> 22 23 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 24 # pragma GCC system_header 25 #endif 26 27 _LIBCPP_PUSH_MACROS 28 #include <__undef_macros> 29 30 #if _LIBCPP_STD_VER >= 20 31 32 _LIBCPP_BEGIN_NAMESPACE_STD 33 34 namespace ranges { 35 36 // TODO(ranges): `ranges::min_element` can now simply delegate to `std::__min_element`. 37 template <class _Ip, class _Sp, class _Proj, class _Comp> 38 _LIBCPP_HIDE_FROM_ABI constexpr _Ip __min_element_impl(_Ip __first, _Sp __last, _Comp& __comp, _Proj& __proj) { 39 if (__first == __last) 40 return __first; 41 42 _Ip __i = __first; 43 while (++__i != __last) 44 if (std::invoke(__comp, std::invoke(__proj, *__i), std::invoke(__proj, *__first))) 45 __first = __i; 46 return __first; 47 } 48 49 struct __min_element { 50 template <forward_iterator _Ip, 51 sentinel_for<_Ip> _Sp, 52 class _Proj = identity, 53 indirect_strict_weak_order<projected<_Ip, _Proj>> _Comp = ranges::less> 54 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Ip 55 operator()(_Ip __first, _Sp __last, _Comp __comp = {}, _Proj __proj = {}) const { 56 return ranges::__min_element_impl(__first, __last, __comp, __proj); 57 } 58 59 template <forward_range _Rp, 60 class _Proj = identity, 61 indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less> 62 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Rp> 63 operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const { 64 return ranges::__min_element_impl(ranges::begin(__r), ranges::end(__r), __comp, __proj); 65 } 66 }; 67 68 inline namespace __cpo { 69 inline constexpr auto min_element = __min_element{}; 70 } // namespace __cpo 71 } // namespace ranges 72 73 _LIBCPP_END_NAMESPACE_STD 74 75 #endif // _LIBCPP_STD_VER >= 20 76 77 _LIBCPP_POP_MACROS 78 79 #endif // _LIBCPP___ALGORITHM_RANGES_MIN_ELEMENT_H 80