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 > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES) 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 static constexpr 36 _Ip __min_element_impl(_Ip __first, _Sp __last, _Comp& __comp, _Proj& __proj) { 37 if (__first == __last) 38 return __first; 39 40 _Ip __i = __first; 41 while (++__i != __last) 42 if (std::invoke(__comp, std::invoke(__proj, *__i), std::invoke(__proj, *__first))) 43 __first = __i; 44 return __first; 45 } 46 47 namespace __min_element { 48 struct __fn { 49 template <forward_iterator _Ip, sentinel_for<_Ip> _Sp, class _Proj = identity, 50 indirect_strict_weak_order<projected<_Ip, _Proj>> _Comp = ranges::less> 51 _LIBCPP_HIDE_FROM_ABI constexpr 52 _Ip operator()(_Ip __first, _Sp __last, _Comp __comp = {}, _Proj __proj = {}) const { 53 return ranges::__min_element_impl(__first, __last, __comp, __proj); 54 } 55 56 template <forward_range _Rp, class _Proj = identity, 57 indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less> 58 _LIBCPP_HIDE_FROM_ABI constexpr 59 borrowed_iterator_t<_Rp> operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const { 60 return ranges::__min_element_impl(ranges::begin(__r), ranges::end(__r), __comp, __proj); 61 } 62 }; 63 } // namespace __min_element 64 65 inline namespace __cpo { 66 inline constexpr auto min_element = __min_element::__fn{}; 67 } // namespace __cpo 68 } // namespace ranges 69 70 _LIBCPP_END_NAMESPACE_STD 71 72 #endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES) 73 74 #endif // _LIBCPP___ALGORITHM_RANGES_MIN_ELEMENT_H 75