--- /dev/null
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// 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_IN_IN_OUT_RESULT_H
+#define _LIBCPP___ALGORITHM_IN_IN_OUT_RESULT_H
+
+#include <__concepts/convertible_to.h>
+#include <__config>
+#include <__utility/move.h>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#ifndef _LIBCPP_HAS_NO_RANGES
+
+namespace ranges {
+template <class _I1, class _I2, class _O1>
+struct in_in_out_result {
+ [[no_unique_address]] _I1 in1;
+ [[no_unique_address]] _I2 in2;
+ [[no_unique_address]] _O1 out;
+
+ template <class _II1, class _II2, class _OO1>
+ requires convertible_to<const _I1&, _II1> && convertible_to<const _I2&, _II2> && convertible_to<const _O1&, _OO1>
+ _LIBCPP_HIDE_FROM_ABI constexpr
+ operator in_in_out_result<_II1, _II2, _OO1>() const& {
+ return {in1, in2, out};
+ }
+
+ template <class _II1, class _II2, class _OO1>
+ requires convertible_to<_I1, _II1> && convertible_to<_I2, _II2> && convertible_to<_O1, _OO1>
+ _LIBCPP_HIDE_FROM_ABI constexpr
+ operator in_in_out_result<_II1, _II2, _OO1>() && {
+ return {_VSTD::move(in1), _VSTD::move(in2), _VSTD::move(out)};
+ }
+};
+} // namespace ranges
+
+#endif // _LIBCPP_HAS_NO_RANGES
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___ALGORITHM_IN_IN_RESULT_H
--- /dev/null
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-no-concepts
+// UNSUPPORTED: libcpp-has-no-incomplete-ranges
+
+// template <class I1, class I2, class O>
+// struct in_in_out_result;
+
+#include <algorithm>
+#include <cassert>
+#include <type_traits>
+
+#include "MoveOnly.h"
+
+template <class T>
+struct ConvertibleFrom {
+ constexpr ConvertibleFrom(T c) : content{c} {}
+ T content;
+};
+
+struct A {
+ explicit A(int);
+};
+// conversion is not implicit
+static_assert(!std::is_constructible_v<std::ranges::in_in_out_result<A, A, A>,
+ std::ranges::in_in_out_result<int, int, int>>);
+
+struct B {
+ B(int);
+};
+static_assert(std::is_constructible_v<std::ranges::in_in_out_result<B, B, B>, std::ranges::in_in_out_result<int, int, int>>);
+static_assert(std::is_constructible_v<std::ranges::in_in_out_result<B, B, B>, std::ranges::in_in_out_result<int, int, int>&>);
+static_assert(std::is_constructible_v<std::ranges::in_in_out_result<B, B, B>, const std::ranges::in_in_out_result<int, int, int>>);
+static_assert(std::is_constructible_v<std::ranges::in_in_out_result<B, B, B>, const std::ranges::in_in_out_result<int, int, int>&>);
+
+struct C {
+ C(int&);
+};
+static_assert(!std::is_constructible_v<std::ranges::in_in_out_result<C, C, C>, std::ranges::in_in_out_result<int, int, int>&>);
+
+static_assert(std::is_convertible_v<std::ranges::in_in_out_result<int, int, int>&,
+ std::ranges::in_in_out_result<long, long, long>>);
+static_assert(std::is_convertible_v<const std::ranges::in_in_out_result<int, int, int>&,
+ std::ranges::in_in_out_result<long, long, long>>);
+static_assert(std::is_convertible_v<std::ranges::in_in_out_result<int, int, int>&&,
+ std::ranges::in_in_out_result<long, long, long>>);
+static_assert(std::is_convertible_v<const std::ranges::in_in_out_result<int, int, int>&&,
+ std::ranges::in_in_out_result<long, long, long>>);
+
+struct NotConvertible {};
+static_assert(!std::is_convertible_v<std::ranges::in_in_out_result<NotConvertible, int, int>,
+ std::ranges::in_in_out_result<int, int, int>>);
+static_assert(!std::is_convertible_v<std::ranges::in_in_out_result<int, NotConvertible, int>,
+ std::ranges::in_in_out_result<int, int, int>>);
+static_assert(!std::is_convertible_v<std::ranges::in_in_out_result<int, int, NotConvertible>,
+ std::ranges::in_in_out_result<int, int, int>>);
+
+static_assert(std::is_constructible_v<std::ranges::in_in_out_result<MoveOnly, MoveOnly, MoveOnly>,
+ std::ranges::in_in_out_result<int, int, int>&>);
+
+static_assert(std::is_move_constructible_v<std::ranges::in_in_out_result<MoveOnly, int, int>>);
+static_assert(std::is_move_constructible_v<std::ranges::in_in_out_result<int, MoveOnly, int>>);
+static_assert(std::is_move_constructible_v<std::ranges::in_in_out_result<int, int, MoveOnly>>);
+
+static_assert(!std::is_copy_constructible_v<std::ranges::in_in_out_result<MoveOnly, int, int>>);
+static_assert(!std::is_copy_constructible_v<std::ranges::in_in_out_result<int, MoveOnly, int>>);
+static_assert(!std::is_copy_constructible_v<std::ranges::in_in_out_result<int, int, MoveOnly>>);
+
+constexpr bool test() {
+ {
+ std::ranges::in_in_out_result<int, double, float> res{10L, 0., 1.f};
+ assert(res.in1 == 10);
+ assert(res.in2 == 0.);
+ assert(res.out == 1.f);
+ std::ranges::in_in_out_result<ConvertibleFrom<int>, ConvertibleFrom<double>, ConvertibleFrom<float>> res2 = res;
+ assert(res2.in1.content == 10);
+ assert(res2.in2.content == 0.);
+ assert(res2.out.content == 1.f);
+ }
+ {
+ std::ranges::in_in_out_result<MoveOnly, int, int> res1{MoveOnly{}, 0, 0};
+ assert(res1.in1.get() == 1);
+ auto res2 = static_cast<std::ranges::in_in_out_result<MoveOnly, int, int>>(std::move(res1));
+ assert(res1.in1.get() == 0);
+ assert(res2.in1.get() == 1);
+ }
+ {
+ auto [in1, in2, out] = std::ranges::in_in_out_result<int, int, int>{1, 2, 3};
+ assert(in1 == 1);
+ assert(in2 == 2);
+ assert(out == 3);
+ }
+ return true;
+}
+
+int main(int, char**) {
+ test();
+ static_assert(test());
+
+ return 0;
+}
#include <algorithm>
struct Empty {};
+struct Empty2 {};
static_assert(sizeof(std::ranges::in_in_result<Empty, int>) == sizeof(int));
static_assert(sizeof(std::ranges::in_in_result<int, Empty>) == sizeof(int));
-static_assert(sizeof(std::ranges::in_in_result<Empty, Empty>) == 2 * sizeof(Empty));
+static_assert(sizeof(std::ranges::in_in_result<Empty, Empty>) == 2);
+
+static_assert(sizeof(std::ranges::in_in_out_result<Empty, int, int>) == 2 * sizeof(int));
+static_assert(sizeof(std::ranges::in_in_out_result<int, Empty, int>) == 2 * sizeof(int));
+static_assert(sizeof(std::ranges::in_in_out_result<int, int, Empty>) == 2 * sizeof(int));
+static_assert(sizeof(std::ranges::in_in_out_result<char, Empty, Empty>) == 2);
+static_assert(sizeof(std::ranges::in_in_out_result<Empty, char, Empty>) == 2);
+static_assert(sizeof(std::ranges::in_in_out_result<Empty, Empty, char>) == 2);
+static_assert(sizeof(std::ranges::in_in_out_result<int, Empty, Empty2>) == sizeof(int));
+static_assert(sizeof(std::ranges::in_in_out_result<Empty, Empty, Empty>) == 3);