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_H 10 #define _LIBCPP___ALGORITHM_RANGES_MIN_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 <__type_traits/is_trivially_copyable.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 >= 20 31 32 _LIBCPP_PUSH_MACROS 33 #include <__undef_macros> 34 35 _LIBCPP_BEGIN_NAMESPACE_STD 36 37 namespace ranges { 38 namespace __min { 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 operator__fn43 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, __b), std::invoke(__proj, __a)) ? __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 operator__fn53 _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 return *ranges::__min_element_impl(__il.begin(), __il.end(), __comp, __proj); 56 } 57 58 template <input_range _Rp, class _Proj = identity, 59 indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less> 60 requires indirectly_copyable_storable<iterator_t<_Rp>, range_value_t<_Rp>*> 61 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr operator__fn62 range_value_t<_Rp> operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const { 63 auto __first = ranges::begin(__r); 64 auto __last = ranges::end(__r); 65 _LIBCPP_ASSERT(__first != __last, "range must contain at least one element"); 66 if constexpr (forward_range<_Rp> && !__is_cheap_to_copy<range_value_t<_Rp>>) { 67 return *ranges::__min_element_impl(__first, __last, __comp, __proj); 68 } else { 69 range_value_t<_Rp> __result = *__first; 70 while (++__first != __last) { 71 if (std::invoke(__comp, std::invoke(__proj, *__first), std::invoke(__proj, __result))) 72 __result = *__first; 73 } 74 return __result; 75 } 76 } 77 }; 78 } // namespace __min 79 80 inline namespace __cpo { 81 inline constexpr auto min = __min::__fn{}; 82 } // namespace __cpo 83 } // namespace ranges 84 85 _LIBCPP_END_NAMESPACE_STD 86 87 _LIBCPP_POP_MACROS 88 89 #endif // _LIBCPP_STD_VER >= 20 && 90 91 #endif // _LIBCPP___ALGORITHM_RANGES_MIN_H 92