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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
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
// template <class O, class T>
// struct out_value_result;
#include <algorithm>
#include <cassert>
#include <type_traits>
#include "MoveOnly.h"
using std::ranges::out_value_result;
//
// Helper structs
//
// only explicit construction
struct IterTypeExplicit {
explicit IterTypeExplicit(int*);
};
// implicit construction
struct IterTypeImplicit {
IterTypeImplicit(int*);
};
struct IterTypeImplicitRef {
IterTypeImplicitRef(int&);
};
struct NotConvertible {};
template <class T>
struct ConvertibleFrom {
constexpr ConvertibleFrom(T c) : content{c} {}
T content;
};
// Standard layout classes can't have virtual functions
struct NonStandardLayoutTypeBase {
virtual ~NonStandardLayoutTypeBase();
};
struct NonStandardLayoutType : public NonStandardLayoutTypeBase {};
//
constexpr bool test_constraints() {
// requires convertible_to<const _OutIter1&, _OutIter2> && convertible_to<const _ValType1&, _ValType2>
static_assert(std::is_constructible_v<out_value_result<int*, int>, out_value_result<int*, int>>);
// test failure when implicit conversion isn't allowed
static_assert(!std::is_constructible_v<out_value_result<IterTypeExplicit, int>, out_value_result<int*, int>>);
// test success when implicit conversion is allowed, checking combinations of value, reference, and const
static_assert(std::is_constructible_v<out_value_result<IterTypeImplicit, int>, out_value_result<int*, int>>);
static_assert(std::is_constructible_v<out_value_result<IterTypeImplicit, int>, out_value_result<int*, int> const>);
static_assert(std::is_constructible_v<out_value_result<IterTypeImplicit, int>, out_value_result<int*, int>&>);
static_assert(std::is_constructible_v<out_value_result<IterTypeImplicit, int>, out_value_result<int*, int> const&>);
static_assert(!std::is_constructible_v<out_value_result<IterTypeImplicitRef, int>, out_value_result<int, int>&>);
// has to be convertible via const&
static_assert(std::is_convertible_v<out_value_result<int, int>&, out_value_result<long, long>>);
static_assert(std::is_convertible_v<const out_value_result<int, int>&, out_value_result<long, long>>);
static_assert(std::is_convertible_v<out_value_result<int, int>&&, out_value_result<long, long>>);
static_assert(std::is_convertible_v<const out_value_result<int, int>&&, out_value_result<long, long>>);
// should be move constructible
static_assert(std::is_move_constructible_v<out_value_result<MoveOnly, int>>);
static_assert(std::is_move_constructible_v<out_value_result<int, MoveOnly>>);
// conversions should not work if there is no conversion
static_assert(!std::is_convertible_v<out_value_result<NotConvertible, int>, out_value_result<int, NotConvertible>>);
static_assert(!std::is_convertible_v<out_value_result<int, NotConvertible>, out_value_result<NotConvertible, int>>);
// check standard layout
static_assert(std::is_standard_layout_v<out_value_result<int, int>>);
static_assert(!std::is_standard_layout_v<out_value_result<NonStandardLayoutType, int>>);
return true;
}
// Test results
constexpr bool test() {
{
// Check that conversion operator works
out_value_result<double, int> res{10, 1};
assert(res.out == 10);
assert(res.value == 1);
out_value_result<ConvertibleFrom<double>, ConvertibleFrom<int>> res2 = res;
assert(res2.out.content == 10);
assert(res2.value.content == 1);
}
{
// Check that out_value_result isn't overconstrained w.r.t. move/copy constructors
out_value_result<MoveOnly, int> res{MoveOnly{}, 10};
assert(res.out.get() == 1);
assert(res.value == 10);
auto res2 = std::move(res);
assert(res.out.get() == 0);
assert(res.value == 10);
assert(res2.out.get() == 1);
assert(res2.value == 10);
}
{
// Check structured binding
auto [out, val] = out_value_result<int, int>{1, 2};
assert(out == 1);
assert(val == 2);
}
{
// Check default construction
out_value_result<int, double> res;
static_assert(std::is_same_v<int, decltype(res.out)>);
static_assert(std::is_same_v<double, decltype(res.value)>);
}
{
// Check aggregate initiazliation
out_value_result<int, int> res = {1, 2};
assert(res.out == 1);
assert(res.value == 2);
}
return true;
}
int main(int, char**) {
test_constraints();
static_assert(test_constraints());
test();
static_assert(test());
return 0;
}
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