96 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++14, c++1710 11// template <class I1, class I2>12// struct in_in_result;13 14#include <algorithm>15#include <cassert>16#include <type_traits>17 18#include "MoveOnly.h"19 20struct A {21 explicit A(int);22};23// no implicit conversion24static_assert(!std::is_constructible_v<std::ranges::in_in_result<A, A>, std::ranges::in_in_result<int, int>>);25 26struct B {27 B(int);28};29// implicit conversion30static_assert(std::is_constructible_v<std::ranges::in_in_result<B, B>, std::ranges::in_in_result<int, int>>);31static_assert(std::is_constructible_v<std::ranges::in_in_result<B, B>, std::ranges::in_in_result<int, int>&>);32static_assert(std::is_constructible_v<std::ranges::in_in_result<B, B>, const std::ranges::in_in_result<int, int>>);33static_assert(std::is_constructible_v<std::ranges::in_in_result<B, B>, const std::ranges::in_in_result<int, int>&>);34 35struct C {36 C(int&);37};38static_assert(!std::is_constructible_v<std::ranges::in_in_result<C, C>, std::ranges::in_in_result<int, int>&>);39 40// has to be convertible via const&41static_assert(std::is_convertible_v<std::ranges::in_in_result<int, int>&, std::ranges::in_in_result<long, long>>);42static_assert(std::is_convertible_v<const std::ranges::in_in_result<int, int>&, std::ranges::in_in_result<long, long>>);43static_assert(std::is_convertible_v<std::ranges::in_in_result<int, int>&&, std::ranges::in_in_result<long, long>>);44static_assert(std::is_convertible_v<const std::ranges::in_in_result<int, int>&&, std::ranges::in_in_result<long, long>>);45 46// should be move constructible47static_assert(std::is_move_constructible_v<std::ranges::in_in_result<MoveOnly, int>>);48static_assert(std::is_move_constructible_v<std::ranges::in_in_result<int, MoveOnly>>);49 50struct NotConvertible {};51// conversions should not work if there is no conversion52static_assert(!std::is_convertible_v<std::ranges::in_in_result<NotConvertible, int>, std::ranges::in_in_result<int, int>>);53static_assert(!std::is_convertible_v<std::ranges::in_in_result<int, NotConvertible>, std::ranges::in_in_result<int, int>>);54 55template <class T>56struct ConstructibleFrom {57 constexpr ConstructibleFrom(T c) : content{c} {}58 T content;59};60 61constexpr bool test() {62 // Checks that conversion operations are correct.63 {64 std::ranges::in_in_result<int, double> res{10L, 0.};65 assert(res.in1 == 10);66 assert(res.in2 == 0.);67 std::ranges::in_in_result<ConstructibleFrom<int>, ConstructibleFrom<double>> res2 = res;68 assert(res2.in1.content == 10);69 assert(res2.in2.content == 0.);70 }71 72 // Checks that conversions are possible when one of the types is move-only.73 {74 std::ranges::in_in_result<MoveOnly, int> res{MoveOnly{}, 0};75 assert(res.in1.get() == 1);76 [[maybe_unused]] auto res2 = static_cast<std::ranges::in_in_result<MoveOnly, int>>(std::move(res));77 assert(res.in1.get() == 0);78 }79 80 // Checks that structured bindings get the correct values.81 {82 auto [in1, in2] = std::ranges::in_in_result<int, int>{1, 2};83 assert(in1 == 1);84 assert(in2 == 2);85 }86 87 return true;88}89 90int main(int, char**) {91 test();92 static_assert(test());93 94 return 0;95}96