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 <initializer_list> 24 25 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 26 # pragma GCC system_header 27 #endif 28 29 #if _LIBCPP_STD_VER > 17 30 31 _LIBCPP_PUSH_MACROS 32 #include <__undef_macros> 33 34 _LIBCPP_BEGIN_NAMESPACE_STD 35 36 namespace ranges { 37 namespace __min { 38 struct __fn { 39 template <class _Tp, class _Proj = identity, 40 indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less> 41 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr 42 const _Tp& operator()(const _Tp& __a, const _Tp& __b, _Comp __comp = {}, _Proj __proj = {}) const { 43 return std::invoke(__comp, std::invoke(__proj, __b), std::invoke(__proj, __a)) ? __b : __a; 44 } 45 46 template <copyable _Tp, class _Proj = identity, 47 indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less> 48 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr 49 _Tp operator()(initializer_list<_Tp> __il, _Comp __comp = {}, _Proj __proj = {}) const { 50 _LIBCPP_ASSERT(__il.begin() != __il.end(), "initializer_list must contain at least one element"); 51 return *ranges::__min_element_impl(__il.begin(), __il.end(), __comp, __proj); 52 } 53 54 template <input_range _Rp, class _Proj = identity, 55 indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less> 56 requires indirectly_copyable_storable<iterator_t<_Rp>, range_value_t<_Rp>*> 57 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr 58 range_value_t<_Rp> operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const { 59 auto __first = ranges::begin(__r); 60 auto __last = ranges::end(__r); 61 62 _LIBCPP_ASSERT(__first != __last, "range must contain at least one element"); 63 64 if constexpr (forward_range<_Rp>) { 65 return *ranges::__min_element_impl(__first, __last, __comp, __proj); 66 } else { 67 range_value_t<_Rp> __result = *__first; 68 while (++__first != __last) { 69 if (std::invoke(__comp, std::invoke(__proj, *__first), std::invoke(__proj, __result))) 70 __result = *__first; 71 } 72 return __result; 73 } 74 } 75 }; 76 } // namespace __min 77 78 inline namespace __cpo { 79 inline constexpr auto min = __min::__fn{}; 80 } // namespace __cpo 81 } // namespace ranges 82 83 _LIBCPP_END_NAMESPACE_STD 84 85 _LIBCPP_POP_MACROS 86 87 #endif // _LIBCPP_STD_VER > 17 && 88 89 #endif // _LIBCPP___ALGORITHM_RANGES_MIN_H 90