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 #if _LIBCPP_STD_VER >= 20 28 29 _LIBCPP_BEGIN_NAMESPACE_STD 30 31 namespace ranges { 32 33 // TODO(ranges): `ranges::min_element` can now simply delegate to `std::__min_element`. 34 template <class _Ip, class _Sp, class _Proj, class _Comp> 35 _LIBCPP_HIDE_FROM_ABI constexpr _Ip __min_element_impl(_Ip __first, _Sp __last, _Comp& __comp, _Proj& __proj) { 36 if (__first == __last) 37 return __first; 38 39 _Ip __i = __first; 40 while (++__i != __last) 41 if (std::invoke(__comp, std::invoke(__proj, *__i), std::invoke(__proj, *__first))) 42 __first = __i; 43 return __first; 44 } 45 46 namespace __min_element { 47 struct __fn { 48 template <forward_iterator _Ip, 49 sentinel_for<_Ip> _Sp, 50 class _Proj = identity, 51 indirect_strict_weak_order<projected<_Ip, _Proj>> _Comp = ranges::less> 52 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr _Ip 53 operator()(_Ip __first, _Sp __last, _Comp __comp = {}, _Proj __proj = {}) const { 54 return ranges::__min_element_impl(__first, __last, __comp, __proj); 55 } 56 57 template <forward_range _Rp, 58 class _Proj = identity, 59 indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less> 60 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Rp> 61 operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const { 62 return ranges::__min_element_impl(ranges::begin(__r), ranges::end(__r), __comp, __proj); 63 } 64 }; 65 } // namespace __min_element 66 67 inline namespace __cpo { 68 inline constexpr auto min_element = __min_element::__fn{}; 69 } // namespace __cpo 70 } // namespace ranges 71 72 _LIBCPP_END_NAMESPACE_STD 73 74 #endif // _LIBCPP_STD_VER >= 20 75 76 #endif // _LIBCPP___ALGORITHM_RANGES_MIN_ELEMENT_H 77