llvm-project/libcxx/include/__algorithm/ranges_max.h

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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___ALGORITHM_RANGES_MAX_H
#define _LIBCPP___ALGORITHM_RANGES_MAX_H
#include <__algorithm/ranges_min_element.h>
#include <__assert>
#include <__concepts/copyable.h>
#include <__config>
#include <__functional/identity.h>
#include <__functional/invoke.h>
#include <__functional/ranges_operations.h>
#include <__iterator/concepts.h>
#include <__iterator/projected.h>
#include <__ranges/access.h>
#include <__ranges/concepts.h>
#include <__utility/move.h>
#include <initializer_list>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
namespace ranges {
namespace __max {
struct __fn {
template <class _Tp, class _Proj = identity,
indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less>
_LIBCPP_HIDE_FROM_ABI constexpr
const _Tp& operator()(const _Tp& __a, const _Tp& __b, _Comp __comp = {}, _Proj __proj = {}) const {
return std::invoke(__comp, std::invoke(__proj, __a), std::invoke(__proj, __b)) ? __b : __a;
}
template <copyable _Tp, class _Proj = identity,
indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less>
_LIBCPP_HIDE_FROM_ABI constexpr
_Tp operator()(initializer_list<_Tp> __il, _Comp __comp = {}, _Proj __proj = {}) const {
_LIBCPP_ASSERT(__il.begin() != __il.end(), "initializer_list must contain at least one element");
auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) { return std::invoke(__comp, __rhs, __lhs); };
return *ranges::__min_element_impl(__il.begin(), __il.end(), __comp_lhs_rhs_swapped, __proj);
}
template <input_range _Rp, class _Proj = identity,
indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less>
requires indirectly_copyable_storable<iterator_t<_Rp>, range_value_t<_Rp>*>
_LIBCPP_HIDE_FROM_ABI constexpr
range_value_t<_Rp> operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
auto __first = ranges::begin(__r);
auto __last = ranges::end(__r);
_LIBCPP_ASSERT(__first != __last, "range must contain at least one element");
if constexpr (forward_range<_Rp>) {
auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) { return std::invoke(__comp, __rhs, __lhs); };
return *ranges::__min_element_impl(std::move(__first), std::move(__last), __comp_lhs_rhs_swapped, __proj);
} else {
range_value_t<_Rp> __result = *__first;
while (++__first != __last) {
if (std::invoke(__comp, std::invoke(__proj, __result), std::invoke(__proj, *__first)))
__result = *__first;
}
return __result;
}
}
};
} // namespace __max
inline namespace __cpo {
inline constexpr auto max = __max::__fn{};
} // namespace __cpo
} // namespace ranges
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP_STD_VER > 17 && && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
#endif // _LIBCPP___ALGORITHM_RANGES_MAX_H