1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10// UNSUPPORTED: c++98, c++03, c++11, c++14
11// <optional>
12
13
14#include <optional>
15#include <type_traits>
16#include <cassert>
17
18#include "archetypes.hpp"
19
20template <class T>
21struct SpecialMemberTest {
22    using O = std::optional<T>;
23
24    static_assert(std::is_default_constructible_v<O>,
25        "optional is always default constructible.");
26    static_assert(std::is_copy_constructible_v<O> == std::is_copy_constructible_v<T>,
27        "optional<T> is copy constructible if and only if T is copy constructible.");
28    static_assert(std::is_move_constructible_v<O> ==
29        (std::is_copy_constructible_v<T> || std::is_move_constructible_v<T>),
30        "optional<T> is move constructible if and only if T is copy or move constructible.");
31    static_assert(std::is_copy_assignable_v<O> ==
32        (std::is_copy_constructible_v<T> && std::is_copy_assignable_v<T>),
33        "optional<T> is copy assignable if and only if T is both copy "
34        "constructible and copy assignable.");
35    static_assert(std::is_move_assignable_v<O> ==
36        ((std::is_move_constructible_v<T> && std::is_move_assignable_v<T>) ||
37         (std::is_copy_constructible_v<T> && std::is_copy_assignable_v<T>)),
38        "optional<T> is move assignable if and only if T is both move constructible and "
39        "move assignable, or both copy constructible and copy assignable.");
40
41    // The following tests are for not-yet-standardized behavior (P0602):
42    static_assert(std::is_trivially_destructible_v<O> ==
43        std::is_trivially_destructible_v<T>,
44        "optional<T> is trivially destructible if and only if T is.");
45    static_assert(std::is_trivially_copy_constructible_v<O> ==
46        std::is_trivially_copy_constructible_v<T>,
47        "optional<T> is trivially copy constructible if and only if T is.");
48    static_assert(std::is_trivially_move_constructible_v<O> ==
49        std::is_trivially_move_constructible_v<T> ||
50        (!std::is_move_constructible_v<T> && std::is_trivially_copy_constructible_v<T>),
51        "optional<T> is trivially move constructible if T is trivially move constructible, "
52        "or if T is trivially copy constructible and is not move constructible.");
53    static_assert(std::is_trivially_copy_assignable_v<O> ==
54        (std::is_trivially_destructible_v<T> &&
55         std::is_trivially_copy_constructible_v<T> &&
56         std::is_trivially_copy_assignable_v<T>),
57        "optional<T> is trivially copy assignable if and only if T is trivially destructible, "
58        "trivially copy constructible, and trivially copy assignable.");
59    static_assert(std::is_trivially_move_assignable_v<O> ==
60        (std::is_trivially_destructible_v<T> &&
61         ((std::is_trivially_move_constructible_v<T> && std::is_trivially_move_assignable_v<T>) ||
62          ((!std::is_move_constructible_v<T> || !std::is_move_assignable_v<T>) &&
63           std::is_trivially_copy_constructible_v<T> && std::is_trivially_copy_assignable_v<T>))),
64        "optional<T> is trivially move assignable if T is trivially destructible, and either "
65        "(1) trivially move constructible and trivially move assignable, or "
66        "(2) not move constructible or not move assignable, and "
67        "trivially copy constructible and trivially copy assignable.");
68};
69
70template <class ...Args> static void sink(Args&&...) {}
71
72template <class ...TestTypes>
73struct DoTestsMetafunction {
74    DoTestsMetafunction() { sink(SpecialMemberTest<TestTypes>{}...); }
75};
76
77struct TrivialMoveNonTrivialCopy {
78    TrivialMoveNonTrivialCopy() = default;
79    TrivialMoveNonTrivialCopy(const TrivialMoveNonTrivialCopy&) {}
80    TrivialMoveNonTrivialCopy(TrivialMoveNonTrivialCopy&&) = default;
81    TrivialMoveNonTrivialCopy& operator=(const TrivialMoveNonTrivialCopy&) { return *this; }
82    TrivialMoveNonTrivialCopy& operator=(TrivialMoveNonTrivialCopy&&) = default;
83};
84
85struct TrivialCopyNonTrivialMove {
86    TrivialCopyNonTrivialMove() = default;
87    TrivialCopyNonTrivialMove(const TrivialCopyNonTrivialMove&) = default;
88    TrivialCopyNonTrivialMove(TrivialCopyNonTrivialMove&&) {}
89    TrivialCopyNonTrivialMove& operator=(const TrivialCopyNonTrivialMove&) = default;
90    TrivialCopyNonTrivialMove& operator=(TrivialCopyNonTrivialMove&&) { return *this; }
91};
92
93int main()
94{
95    sink(
96        ImplicitTypes::ApplyTypes<DoTestsMetafunction>{},
97        ExplicitTypes::ApplyTypes<DoTestsMetafunction>{},
98        NonLiteralTypes::ApplyTypes<DoTestsMetafunction>{},
99        NonTrivialTypes::ApplyTypes<DoTestsMetafunction>{},
100        DoTestsMetafunction<TrivialMoveNonTrivialCopy, TrivialCopyNonTrivialMove>{}
101    );
102}
103