const_T.pass.cpp revision 0cdbe6048173c1f05628dbc85430acf191a3e173 
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// <optional>
11
12// constexpr optional(const T& v);
13
14#include <experimental/optional>
15#include <type_traits>
16#include <cassert>
17
18#if _LIBCPP_STD_VER > 11
19
20using std::experimental::optional;
21
22class X
23{
24    int i_;
25public:
26    X(int i) : i_(i) {}
27
28    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
29};
30
31class Y
32{
33    int i_;
34public:
35    constexpr Y(int i) : i_(i) {}
36
37    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
38};
39
40class Z
41{
42    int i_;
43public:
44    Z(int i) : i_(i) {}
45    Z(const Z&) {throw 6;}
46};
47
48
49#endif  // _LIBCPP_STD_VER > 11
50
51int main()
52{
53#if _LIBCPP_STD_VER > 11
54    {
55        typedef int T;
56        constexpr T t(5);
57        constexpr optional<T> opt(t);
58        static_assert(static_cast<bool>(opt) == true, "");
59        static_assert(*opt == 5, "");
60
61        struct test_constexpr_ctor
62            : public optional<T>
63        {
64            constexpr test_constexpr_ctor(const T&) {}
65        };
66
67    }
68    {
69        typedef double T;
70        constexpr T t(3);
71        constexpr optional<T> opt(t);
72        static_assert(static_cast<bool>(opt) == true, "");
73        static_assert(*opt == 3, "");
74
75        struct test_constexpr_ctor
76            : public optional<T>
77        {
78            constexpr test_constexpr_ctor(const T&) {}
79        };
80
81    }
82    {
83        typedef X T;
84        const T t(3);
85        optional<T> opt(t);
86        assert(static_cast<bool>(opt) == true);
87        assert(*opt == 3);
88    }
89    {
90        typedef Y T;
91        constexpr T t(3);
92        constexpr optional<T> opt(t);
93        static_assert(static_cast<bool>(opt) == true, "");
94        static_assert(*opt == 3, "");
95
96        struct test_constexpr_ctor
97            : public optional<T>
98        {
99            constexpr test_constexpr_ctor(const T&) {}
100        };
101
102    }
103    {
104        typedef Z T;
105        try
106        {
107            const T t(3);
108            optional<T> opt(t);
109            assert(false);
110        }
111        catch (int i)
112        {
113            assert(i == 6);
114        }
115    }
116#endif  // _LIBCPP_STD_VER > 11
117}
118