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// template <class U, class... Args>
13//   void optional<T>::emplace(initializer_list<U> il, Args&&... args);
14
15#include <experimental/optional>
16#include <type_traits>
17#include <cassert>
18#include <vector>
19
20#if _LIBCPP_STD_VER > 11
21
22using std::experimental::optional;
23
24class X
25{
26    int i_;
27    int j_ = 0;
28public:
29    static bool dtor_called;
30    constexpr X() : i_(0) {}
31    constexpr X(int i) : i_(i) {}
32    constexpr X(std::initializer_list<int> il) : i_(il.begin()[0]), j_(il.begin()[1]) {}
33    ~X() {dtor_called = true;}
34
35    friend constexpr bool operator==(const X& x, const X& y)
36        {return x.i_ == y.i_ && x.j_ == y.j_;}
37};
38
39bool X::dtor_called = false;
40
41class Y
42{
43    int i_;
44    int j_ = 0;
45public:
46    constexpr Y() : i_(0) {}
47    constexpr Y(int i) : i_(i) {}
48    constexpr Y(std::initializer_list<int> il) : i_(il.begin()[0]), j_(il.begin()[1]) {}
49
50    friend constexpr bool operator==(const Y& x, const Y& y)
51        {return x.i_ == y.i_ && x.j_ == y.j_;}
52};
53
54class Z
55{
56    int i_;
57    int j_ = 0;
58public:
59    static bool dtor_called;
60    constexpr Z() : i_(0) {}
61    constexpr Z(int i) : i_(i) {}
62    constexpr Z(std::initializer_list<int> il) : i_(il.begin()[0]), j_(il.begin()[1])
63        {throw 6;}
64    ~Z() {dtor_called = true;}
65
66    friend constexpr bool operator==(const Z& x, const Z& y)
67        {return x.i_ == y.i_ && x.j_ == y.j_;}
68};
69
70bool Z::dtor_called = false;
71
72#endif  // _LIBCPP_STD_VER > 11
73
74int main()
75{
76#if _LIBCPP_STD_VER > 11
77    {
78        X x;
79        {
80            optional<X> opt(x);
81            assert(X::dtor_called == false);
82            opt.emplace({1, 2});
83            assert(X::dtor_called == true);
84            assert(*opt == X({1, 2}));
85        }
86    }
87    {
88        optional<std::vector<int>> opt;
89        opt.emplace({1, 2, 3}, std::allocator<int>());
90        assert(static_cast<bool>(opt) == true);
91        assert(*opt == std::vector<int>({1, 2, 3}));
92    }
93    {
94        optional<Y> opt;
95        opt.emplace({1, 2});
96        assert(static_cast<bool>(opt) == true);
97        assert(*opt == Y({1, 2}));
98    }
99    {
100        Z z;
101        optional<Z> opt(z);
102        try
103        {
104            assert(static_cast<bool>(opt) == true);
105            assert(Z::dtor_called == false);
106            opt.emplace({1, 2});
107        }
108        catch (int i)
109        {
110            assert(i == 6);
111            assert(static_cast<bool>(opt) == false);
112            assert(Z::dtor_called == true);
113        }
114    }
115#endif  // _LIBCPP_STD_VER > 11
116}
117