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()(_LIBCPP_LIFETIMEBOUND const _Tp& __a, 43 _LIBCPP_LIFETIMEBOUND const _Tp& __b, 44 _Comp __comp = {}, 45 _Proj __proj = {}) const { 46 return std::invoke(__comp, std::invoke(__proj, __b), std::invoke(__proj, __a)) ? __b : __a; 47 } 48 49 template <copyable _Tp, class _Proj = identity, 50 indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less> 51 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr 52 _Tp operator()(initializer_list<_Tp> __il, _Comp __comp = {}, _Proj __proj = {}) const { 53 _LIBCPP_ASSERT(__il.begin() != __il.end(), "initializer_list must contain at least one element"); 54 return *ranges::__min_element_impl(__il.begin(), __il.end(), __comp, __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 return *ranges::__min_element_impl(__first, __last, __comp, __proj); 69 } else { 70 range_value_t<_Rp> __result = *__first; 71 while (++__first != __last) { 72 if (std::invoke(__comp, std::invoke(__proj, *__first), std::invoke(__proj, __result))) 73 __result = *__first; 74 } 75 return __result; 76 } 77 } 78 }; 79 } // namespace __min 80 81 inline namespace __cpo { 82 inline constexpr auto min = __min::__fn{}; 83 } // namespace __cpo 84 } // namespace ranges 85 86 _LIBCPP_END_NAMESPACE_STD 87 88 _LIBCPP_POP_MACROS 89 90 #endif // _LIBCPP_STD_VER > 17 && 91 92 #endif // _LIBCPP___ALGORITHM_RANGES_MIN_H 93