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_MAX_H 10 #define _LIBCPP___ALGORITHM_RANGES_MAX_H 11 12 #include <__algorithm/ranges_min_element.h> 13 #include <__assert> 14 #include <__concepts/copyable.h> 15 #include <__config> 16 #include <__functional/identity.h> 17 #include <__functional/invoke.h> 18 #include <__functional/ranges_operations.h> 19 #include <__iterator/concepts.h> 20 #include <__iterator/projected.h> 21 #include <__ranges/access.h> 22 #include <__ranges/concepts.h> 23 #include <__utility/move.h> 24 #include <initializer_list> 25 26 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 27 # pragma GCC system_header 28 #endif 29 30 #if _LIBCPP_STD_VER > 17 31 32 _LIBCPP_PUSH_MACROS 33 #include <__undef_macros> 34 35 _LIBCPP_BEGIN_NAMESPACE_STD 36 37 namespace ranges { 38 namespace __max { 39 struct __fn { 40 template <class _Tp, class _Proj = identity, 41 indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less> 42 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr 43 const _Tp& operator()(const _Tp& __a, const _Tp& __b, _Comp __comp = {}, _Proj __proj = {}) const { 44 return std::invoke(__comp, std::invoke(__proj, __a), std::invoke(__proj, __b)) ? __b : __a; 45 } 46 47 template <copyable _Tp, class _Proj = identity, 48 indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less> 49 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr 50 _Tp operator()(initializer_list<_Tp> __il, _Comp __comp = {}, _Proj __proj = {}) const { 51 _LIBCPP_ASSERT(__il.begin() != __il.end(), "initializer_list must contain at least one element"); 52 53 auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) { return std::invoke(__comp, __rhs, __lhs); }; 54 return *ranges::__min_element_impl(__il.begin(), __il.end(), __comp_lhs_rhs_swapped, __proj); 55 } 56 57 template <input_range _Rp, class _Proj = identity, 58 indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less> 59 requires indirectly_copyable_storable<iterator_t<_Rp>, range_value_t<_Rp>*> 60 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr 61 range_value_t<_Rp> operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const { 62 auto __first = ranges::begin(__r); 63 auto __last = ranges::end(__r); 64 65 _LIBCPP_ASSERT(__first != __last, "range must contain at least one element"); 66 67 if constexpr (forward_range<_Rp>) { 68 auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) { return std::invoke(__comp, __rhs, __lhs); }; 69 return *ranges::__min_element_impl(std::move(__first), std::move(__last), __comp_lhs_rhs_swapped, __proj); 70 } else { 71 range_value_t<_Rp> __result = *__first; 72 while (++__first != __last) { 73 if (std::invoke(__comp, std::invoke(__proj, __result), std::invoke(__proj, *__first))) 74 __result = *__first; 75 } 76 return __result; 77 } 78 } 79 }; 80 } // namespace __max 81 82 inline namespace __cpo { 83 inline constexpr auto max = __max::__fn{}; 84 } // namespace __cpo 85 } // namespace ranges 86 87 _LIBCPP_END_NAMESPACE_STD 88 89 _LIBCPP_POP_MACROS 90 91 #endif // _LIBCPP_STD_VER > 17 && 92 93 #endif // _LIBCPP___ALGORITHM_RANGES_MAX_H 94