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()(_LIBCPP_LIFETIMEBOUND const _Tp& __a, 44 _LIBCPP_LIFETIMEBOUND const _Tp& __b, 45 _Comp __comp = {}, 46 _Proj __proj = {}) const { 47 return std::invoke(__comp, std::invoke(__proj, __a), std::invoke(__proj, __b)) ? __b : __a; 48 } 49 50 template <copyable _Tp, class _Proj = identity, 51 indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less> 52 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr 53 _Tp operator()(initializer_list<_Tp> __il, _Comp __comp = {}, _Proj __proj = {}) const { 54 _LIBCPP_ASSERT(__il.begin() != __il.end(), "initializer_list must contain at least one element"); 55 56 auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) { return std::invoke(__comp, __rhs, __lhs); }; 57 return *ranges::__min_element_impl(__il.begin(), __il.end(), __comp_lhs_rhs_swapped, __proj); 58 } 59 60 template <input_range _Rp, class _Proj = identity, 61 indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less> 62 requires indirectly_copyable_storable<iterator_t<_Rp>, range_value_t<_Rp>*> 63 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr 64 range_value_t<_Rp> operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const { 65 auto __first = ranges::begin(__r); 66 auto __last = ranges::end(__r); 67 68 _LIBCPP_ASSERT(__first != __last, "range must contain at least one element"); 69 70 if constexpr (forward_range<_Rp>) { 71 auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) { return std::invoke(__comp, __rhs, __lhs); }; 72 return *ranges::__min_element_impl(std::move(__first), std::move(__last), __comp_lhs_rhs_swapped, __proj); 73 } else { 74 range_value_t<_Rp> __result = *__first; 75 while (++__first != __last) { 76 if (std::invoke(__comp, std::invoke(__proj, __result), std::invoke(__proj, *__first))) 77 __result = *__first; 78 } 79 return __result; 80 } 81 } 82 }; 83 } // namespace __max 84 85 inline namespace __cpo { 86 inline constexpr auto max = __max::__fn{}; 87 } // namespace __cpo 88 } // namespace ranges 89 90 _LIBCPP_END_NAMESPACE_STD 91 92 _LIBCPP_POP_MACROS 93 94 #endif // _LIBCPP_STD_VER > 17 && 95 96 #endif // _LIBCPP___ALGORITHM_RANGES_MAX_H 97