1 // Copyright Louis Dionne 2013-2017
2 // Distributed under the Boost Software License, Version 1.0.
3 // (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
4
5 #include <boost/hana/assert.hpp>
6 #include <boost/hana/tuple.hpp>
7
8 #include <string>
9 #include <type_traits>
10 namespace hana = boost::hana;
11
12
13 struct DefaultOnly {
14 int data_;
15 DefaultOnly(DefaultOnly const&) = delete;
16 DefaultOnly& operator=(DefaultOnly const&) = delete;
17
18 static int count;
19
DefaultOnlyDefaultOnly20 DefaultOnly() : data_(-1) { ++count; }
~DefaultOnlyDefaultOnly21 ~DefaultOnly() { data_ = 0; --count; }
22
operator ==(DefaultOnly const & x,DefaultOnly const & y)23 friend bool operator==(DefaultOnly const& x, DefaultOnly const& y)
24 { return x.data_ == y.data_; }
25
operator <(DefaultOnly const & x,DefaultOnly const & y)26 friend bool operator< (DefaultOnly const& x, DefaultOnly const& y)
27 { return x.data_ < y.data_; }
28 };
29
30 int DefaultOnly::count = 0;
31
32 struct NoDefault {
33 NoDefault() = delete;
NoDefaultNoDefault34 explicit NoDefault(int) { }
35 };
36
37 struct IllFormedDefault {
IllFormedDefaultIllFormedDefault38 IllFormedDefault(int x) : value(x) {}
39 template <bool Pred = false>
IllFormedDefaultIllFormedDefault40 constexpr IllFormedDefault() {
41 static_assert(Pred,
42 "The default constructor should not be instantiated");
43 }
44 int value;
45 };
46
main()47 int main() {
48 {
49 hana::tuple<> t; (void)t;
50 }
51 {
52 hana::tuple<int> t;
53 BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 0);
54 }
55 {
56 hana::tuple<int, char*> t;
57 BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 0);
58 BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == nullptr);
59 }
60 {
61 hana::tuple<int, char*, std::string> t;
62 BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 0);
63 BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == nullptr);
64 BOOST_HANA_RUNTIME_CHECK(hana::at_c<2>(t) == "");
65 }
66 {
67 hana::tuple<int, char*, std::string, DefaultOnly> t;
68 BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 0);
69 BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == nullptr);
70 BOOST_HANA_RUNTIME_CHECK(hana::at_c<2>(t) == "");
71 BOOST_HANA_RUNTIME_CHECK(hana::at_c<3>(t) == DefaultOnly());
72 }
73 {
74 // See LLVM bug #21157.
75 static_assert(!std::is_default_constructible<
76 hana::tuple<NoDefault>
77 >(), "");
78 static_assert(!std::is_default_constructible<
79 hana::tuple<DefaultOnly, NoDefault>
80 >(), "");
81 static_assert(!std::is_default_constructible<
82 hana::tuple<NoDefault, DefaultOnly, NoDefault>
83 >(), "");
84 }
85 {
86 struct T { };
87 struct U { };
88 struct V { };
89
90 constexpr hana::tuple<> z0; (void)z0;
91 constexpr hana::tuple<T> z1; (void)z1;
92 constexpr hana::tuple<T, U> z2; (void)z2;
93 constexpr hana::tuple<T, U, V> z3; (void)z3;
94 }
95 {
96 constexpr hana::tuple<int> t;
97 BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 0);
98 }
99 {
100 constexpr hana::tuple<int, char*> t;
101 BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 0);
102 BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == nullptr);
103 }
104
105 // Make sure we can hold non default-constructible elements, and that
106 // it does not trigger an error in the default constructor.
107 {
108 {
109 IllFormedDefault v(0);
110 hana::tuple<IllFormedDefault> t1(v);
111 hana::tuple<IllFormedDefault> t2{v};
112 hana::tuple<IllFormedDefault> t3 = {v};
113 (void)t1;(void)t2;(void)t3; // remove spurious unused variable warning on GCC
114 }
115 {
116 hana::tuple<NoDefault> t1(0);
117 hana::tuple<NoDefault> t2{0};
118 hana::tuple<NoDefault> t3 = {0};
119 (void)t1;(void)t2;(void)t3; // remove spurious unused variable warning on GCC
120 }
121 {
122 NoDefault v(0);
123 hana::tuple<NoDefault> t1(v);
124 hana::tuple<NoDefault> t2{v};
125 hana::tuple<NoDefault> t3 = {v};
126 (void)t1;(void)t2;(void)t3; // remove spurious unused variable warning on GCC
127 }
128 }
129
130 // Make sure a tuple_t can be default-constructed
131 {
132 struct T;
133 struct U;
134
135 using Types = decltype(hana::tuple_t<T, U>);
136 Types t{}; (void)t;
137 }
138 }
139