summaryrefslogtreecommitdiff
path: root/clang/test/CXX/temp/temp.decls/temp.variadic/example-tuple.cpp
blob: 9de5fa84b48a25a5d6148b57f5de855f4cf6c4f2 (about) (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s

// Example tuple implementation from the variadic templates proposal,
// ISO C++ committee document number N2080.

// Helper type traits
template<typename T>
struct add_reference {
  typedef T &type;
};

template<typename T>
struct add_reference<T&> {
  typedef T &type;
};

template<typename T>
struct add_const_reference {
  typedef T const &type;
};

template<typename T>
struct add_const_reference<T&> {
  typedef T &type;
};

template<typename T, typename U>
struct is_same {
  static const bool value = false;
};

template<typename T>
struct is_same<T, T> {
  static const bool value = true;
};

template<typename T> 
class reference_wrapper { 
  T *ptr;

public:
  reference_wrapper(T& t) : ptr(&t) { }
  operator T&() const { return *ptr; }
};

template<typename T> reference_wrapper<T> ref(T& t) { 
  return reference_wrapper<T>(t); 
}
template<typename T> reference_wrapper<const T> cref(const T& t) {
  return reference_wrapper<const T>(t); 
}

template<typename... Values> class tuple;

// Basis case: zero-length tuple
template<> class tuple<> { };

template<typename Head, typename... Tail> 
class tuple<Head, Tail...> : private tuple<Tail...> { 
  typedef tuple<Tail...> inherited;

public: 
  tuple() { }
  // implicit copy-constructor is okay

  // Construct tuple from separate arguments. 
  tuple(typename add_const_reference<Head>::type v,
        typename add_const_reference<Tail>::type... vtail) 
    : m_head(v), inherited(vtail...) { }

  // Construct tuple from another tuple. 
  template<typename... VValues> tuple(const tuple<VValues...>& other)
    : m_head(other.head()), inherited(other.tail()) { }

  template<typename... VValues> tuple& 
  operator=(const tuple<VValues...>& other) {
    m_head = other.head(); 
    tail() = other.tail(); 
    return *this;
  }

  typename add_reference<Head>::type head() { return m_head; } 
  typename add_reference<const Head>::type head() const { return m_head; }
  inherited& tail() { return *this; } 
  const inherited& tail() const { return *this; }

protected: 
  Head m_head;
};

void test_tuple() {
  tuple<> t0a;
  tuple<> t0b(t0a);
  t0a = t0b;

  tuple<int> t1a;
  tuple<int> t1b(17);
  tuple<int> t1c(t1b);
  t1a = t1b;

  tuple<float> t1d(3.14159);
  tuple<float> t1e(t1d);
  t1d = t1e;

  int i;
  float f;
  double d;
  tuple<int*, float*, double*> t3a(&i, &f, &d);
}

// Creation functions
template<typename T> 
struct make_tuple_result {
  typedef T type;
};

template<typename T> 
struct make_tuple_result<reference_wrapper<T> > {
  typedef T& type;
};

template<typename... Values> 
tuple<typename make_tuple_result<Values>::type...> 
make_tuple(const Values&... values) {
  return tuple<typename make_tuple_result<Values>::type...>(values...);
}

template<typename... Values> 
tuple<Values&...> tie(Values&... values) {
  return tuple<Values&...>(values...);
}

template<typename T> const T *addr(const T& ref) { return &ref; }
void test_creation_functions() {
  int i;
  float f;
  double d;
  const tuple<int, float&, const double&> *t3p = addr(make_tuple(i, ref(f), cref(d)));
  const tuple<int&, float&, double&> *t3q = addr(tie(i, f, d));
}

// Helper classes
template<typename Tuple> struct tuple_size;

template<typename... Values> struct tuple_size<tuple<Values...> > {
  static const int value = sizeof...(Values);
};

int check_tuple_size_0[tuple_size<tuple<> >::value == 0? 1 : -1];
int check_tuple_size_1[tuple_size<tuple<int>>::value == 1? 1 : -1];
int check_tuple_size_2[tuple_size<tuple<float, double>>::value == 2? 1 : -1];
int check_tuple_size_3[tuple_size<tuple<char, unsigned char, signed char>>::value == 3? 1 : -1];

template<int I, typename Tuple> struct tuple_element;

template<int I, typename Head, typename... Tail> 
struct tuple_element<I, tuple<Head, Tail...> > {
  typedef typename tuple_element<I-1, tuple<Tail...> >::type type;
};

template<typename Head, typename... Tail> 
struct tuple_element<0, tuple<Head, Tail...> > {
  typedef Head type;
};

int check_tuple_element_0[is_same<tuple_element<0, tuple<int&, float, double>>::type,
                                  int&>::value? 1 : -1];

int check_tuple_element_1[is_same<tuple_element<1, tuple<int&, float, double>>::type,
                                  float>::value? 1 : -1];

int check_tuple_element_2[is_same<tuple_element<2, tuple<int&, float, double>>::type,
                                  double>::value? 1 : -1];

// Element access
template<int I, typename Tuple> class get_impl;
template<int I, typename Head, typename... Values> 
class get_impl<I, tuple<Head, Values...> > {
  typedef typename tuple_element<I-1, tuple<Values...> >::type Element;
  typedef typename add_reference<Element>::type RJ; 
  typedef typename add_const_reference<Element>::type PJ;
  typedef get_impl<I-1, tuple<Values...> > Next;
public: 
  static RJ get(tuple<Head, Values...>& t) { return Next::get(t.tail()); }
  static PJ get(const tuple<Head, Values...>& t) { return Next::get(t.tail()); }
};

template<typename Head, typename... Values> 
class get_impl<0, tuple<Head, Values...> > {
  typedef typename add_reference<Head>::type RJ; 
  typedef typename add_const_reference<Head>::type PJ;
public: 
  static RJ get(tuple<Head, Values...>& t) { return t.head(); } 
  static PJ get(const tuple<Head, Values...>& t) { return t.head(); }
};

template<int I, typename... Values> typename add_reference<
typename tuple_element<I, tuple<Values...> >::type >::type
get(tuple<Values...>& t) { 
  return get_impl<I, tuple<Values...> >::get(t);
}

template<int I, typename... Values> typename add_const_reference<
typename tuple_element<I, tuple<Values...> >::type >::type
get(const tuple<Values...>& t) { 
  return get_impl<I, tuple<Values...> >::get(t);
}

void test_element_access(tuple<int*, float*, double*&> t3) {
  int i;
  float f;
  double d;
  get<0>(t3) = &i;
  get<1>(t3) = &f;
  get<2>(t3) = &d;
}

// Relational operators
inline bool operator==(const tuple<>&, const tuple<>&) { return true; }

template<typename T, typename... TTail, typename U, typename... UTail> 
bool operator==(const tuple<T, TTail...>& t, const tuple<U, UTail...>& u) {
  return t.head() == u.head() && t.tail() == u.tail();
}

template<typename... TValues, typename... UValues> 
bool operator!=(const tuple<TValues...>& t, const tuple<UValues...>& u) {
  return !(t == u); 
}

inline bool operator<(const tuple<>&, const tuple<>&) { return false; }

template<typename T, typename... TTail, typename U, typename... UTail> 
bool operator<(const tuple<T, TTail...>& t, const tuple<U, UTail...>& u) {
  return (t.head() < u.head() || (!(t.head() < u.head()) && t.tail() < u.tail()));
}

template<typename... TValues, typename... UValues> 
bool operator>(const tuple<TValues...>& t, const tuple<UValues...>& u) {
  return u < t;
}

template<typename... TValues, typename... UValues>
bool operator<=(const tuple<TValues...>& t, const tuple<UValues...>& u) {
  return !(u < t);
}

template<typename... TValues, typename... UValues>
bool operator>=(const tuple<TValues...>& t, const tuple<UValues...>& u) {
  return !(t < u);
}

void test_relational_operators(tuple<int*, float*, double*> t3) {
  (void)(t3 == t3);
  (void)(t3 != t3);
  (void)(t3 < t3);
  (void)(t3 <= t3);
  (void)(t3 >= t3);
  (void)(t3 > t3);
};