1 // RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
2 // expected-no-diagnostics
3
4 // Example tuple implementation from the variadic templates proposal,
5 // ISO C++ committee document number N2080.
6
7 // Helper type traits
8 template<typename T>
9 struct add_reference {
10 typedef T &type;
11 };
12
13 template<typename T>
14 struct add_reference<T&> {
15 typedef T &type;
16 };
17
18 template<typename T>
19 struct add_const_reference {
20 typedef T const &type;
21 };
22
23 template<typename T>
24 struct add_const_reference<T&> {
25 typedef T &type;
26 };
27
28 template<typename T, typename U>
29 struct is_same {
30 static const bool value = false;
31 };
32
33 template<typename T>
34 struct is_same<T, T> {
35 static const bool value = true;
36 };
37
38 template<typename T>
39 class reference_wrapper {
40 T *ptr;
41
42 public:
reference_wrapper(T & t)43 reference_wrapper(T& t) : ptr(&t) { }
operator T&() const44 operator T&() const { return *ptr; }
45 };
46
ref(T & t)47 template<typename T> reference_wrapper<T> ref(T& t) {
48 return reference_wrapper<T>(t);
49 }
cref(const T & t)50 template<typename T> reference_wrapper<const T> cref(const T& t) {
51 return reference_wrapper<const T>(t);
52 }
53
54 template<typename... Values> class tuple;
55
56 // Basis case: zero-length tuple
57 template<> class tuple<> { };
58
59 template<typename Head, typename... Tail>
60 class tuple<Head, Tail...> : private tuple<Tail...> {
61 typedef tuple<Tail...> inherited;
62
63 public:
tuple()64 tuple() { }
65 // implicit copy-constructor is okay
66
67 // Construct tuple from separate arguments.
tuple(typename add_const_reference<Head>::type v,typename add_const_reference<Tail>::type...vtail)68 tuple(typename add_const_reference<Head>::type v,
69 typename add_const_reference<Tail>::type... vtail)
70 : m_head(v), inherited(vtail...) { }
71
72 // Construct tuple from another tuple.
tuple(const tuple<VValues...> & other)73 template<typename... VValues> tuple(const tuple<VValues...>& other)
74 : m_head(other.head()), inherited(other.tail()) { }
75
76 template<typename... VValues> tuple&
operator =(const tuple<VValues...> & other)77 operator=(const tuple<VValues...>& other) {
78 m_head = other.head();
79 tail() = other.tail();
80 return *this;
81 }
82
head()83 typename add_reference<Head>::type head() { return m_head; }
head() const84 typename add_reference<const Head>::type head() const { return m_head; }
tail()85 inherited& tail() { return *this; }
tail() const86 const inherited& tail() const { return *this; }
87
88 protected:
89 Head m_head;
90 };
91
test_tuple()92 void test_tuple() {
93 tuple<> t0a;
94 tuple<> t0b(t0a);
95 t0a = t0b;
96
97 tuple<int> t1a;
98 tuple<int> t1b(17);
99 tuple<int> t1c(t1b);
100 t1a = t1b;
101
102 tuple<float> t1d(3.14159);
103 tuple<float> t1e(t1d);
104 t1d = t1e;
105
106 int i;
107 float f;
108 double d;
109 tuple<int*, float*, double*> t3a(&i, &f, &d);
110 }
111
112 // Creation functions
113 template<typename T>
114 struct make_tuple_result {
115 typedef T type;
116 };
117
118 template<typename T>
119 struct make_tuple_result<reference_wrapper<T> > {
120 typedef T& type;
121 };
122
123 template<typename... Values>
124 tuple<typename make_tuple_result<Values>::type...>
make_tuple(const Values &...values)125 make_tuple(const Values&... values) {
126 return tuple<typename make_tuple_result<Values>::type...>(values...);
127 }
128
129 template<typename... Values>
tie(Values &...values)130 tuple<Values&...> tie(Values&... values) {
131 return tuple<Values&...>(values...);
132 }
133
addr(const T & ref)134 template<typename T> const T *addr(const T& ref) { return &ref; }
test_creation_functions()135 void test_creation_functions() {
136 int i;
137 float f;
138 double d;
139 const tuple<int, float&, const double&> *t3p = addr(make_tuple(i, ref(f), cref(d)));
140 const tuple<int&, float&, double&> *t3q = addr(tie(i, f, d));
141 }
142
143 // Helper classes
144 template<typename Tuple> struct tuple_size;
145
146 template<typename... Values> struct tuple_size<tuple<Values...> > {
147 static const int value = sizeof...(Values);
148 };
149
150 int check_tuple_size_0[tuple_size<tuple<> >::value == 0? 1 : -1];
151 int check_tuple_size_1[tuple_size<tuple<int>>::value == 1? 1 : -1];
152 int check_tuple_size_2[tuple_size<tuple<float, double>>::value == 2? 1 : -1];
153 int check_tuple_size_3[tuple_size<tuple<char, unsigned char, signed char>>::value == 3? 1 : -1];
154
155 template<int I, typename Tuple> struct tuple_element;
156
157 template<int I, typename Head, typename... Tail>
158 struct tuple_element<I, tuple<Head, Tail...> > {
159 typedef typename tuple_element<I-1, tuple<Tail...> >::type type;
160 };
161
162 template<typename Head, typename... Tail>
163 struct tuple_element<0, tuple<Head, Tail...> > {
164 typedef Head type;
165 };
166
167 int check_tuple_element_0[is_same<tuple_element<0, tuple<int&, float, double>>::type,
168 int&>::value? 1 : -1];
169
170 int check_tuple_element_1[is_same<tuple_element<1, tuple<int&, float, double>>::type,
171 float>::value? 1 : -1];
172
173 int check_tuple_element_2[is_same<tuple_element<2, tuple<int&, float, double>>::type,
174 double>::value? 1 : -1];
175
176 // Element access
177 template<int I, typename Tuple> class get_impl;
178 template<int I, typename Head, typename... Values>
179 class get_impl<I, tuple<Head, Values...> > {
180 typedef typename tuple_element<I-1, tuple<Values...> >::type Element;
181 typedef typename add_reference<Element>::type RJ;
182 typedef typename add_const_reference<Element>::type PJ;
183 typedef get_impl<I-1, tuple<Values...> > Next;
184 public:
get(tuple<Head,Values...> & t)185 static RJ get(tuple<Head, Values...>& t) { return Next::get(t.tail()); }
get(const tuple<Head,Values...> & t)186 static PJ get(const tuple<Head, Values...>& t) { return Next::get(t.tail()); }
187 };
188
189 template<typename Head, typename... Values>
190 class get_impl<0, tuple<Head, Values...> > {
191 typedef typename add_reference<Head>::type RJ;
192 typedef typename add_const_reference<Head>::type PJ;
193 public:
get(tuple<Head,Values...> & t)194 static RJ get(tuple<Head, Values...>& t) { return t.head(); }
get(const tuple<Head,Values...> & t)195 static PJ get(const tuple<Head, Values...>& t) { return t.head(); }
196 };
197
198 template<int I, typename... Values> typename add_reference<
199 typename tuple_element<I, tuple<Values...> >::type >::type
get(tuple<Values...> & t)200 get(tuple<Values...>& t) {
201 return get_impl<I, tuple<Values...> >::get(t);
202 }
203
204 template<int I, typename... Values> typename add_const_reference<
205 typename tuple_element<I, tuple<Values...> >::type >::type
get(const tuple<Values...> & t)206 get(const tuple<Values...>& t) {
207 return get_impl<I, tuple<Values...> >::get(t);
208 }
209
test_element_access(tuple<int *,float *,double * &> t3)210 void test_element_access(tuple<int*, float*, double*&> t3) {
211 int i;
212 float f;
213 double d;
214 get<0>(t3) = &i;
215 get<1>(t3) = &f;
216 get<2>(t3) = &d;
217 }
218
219 // Relational operators
operator ==(const tuple<> &,const tuple<> &)220 inline bool operator==(const tuple<>&, const tuple<>&) { return true; }
221
222 template<typename T, typename... TTail, typename U, typename... UTail>
operator ==(const tuple<T,TTail...> & t,const tuple<U,UTail...> & u)223 bool operator==(const tuple<T, TTail...>& t, const tuple<U, UTail...>& u) {
224 return t.head() == u.head() && t.tail() == u.tail();
225 }
226
227 template<typename... TValues, typename... UValues>
operator !=(const tuple<TValues...> & t,const tuple<UValues...> & u)228 bool operator!=(const tuple<TValues...>& t, const tuple<UValues...>& u) {
229 return !(t == u);
230 }
231
operator <(const tuple<> &,const tuple<> &)232 inline bool operator<(const tuple<>&, const tuple<>&) { return false; }
233
234 template<typename T, typename... TTail, typename U, typename... UTail>
operator <(const tuple<T,TTail...> & t,const tuple<U,UTail...> & u)235 bool operator<(const tuple<T, TTail...>& t, const tuple<U, UTail...>& u) {
236 return (t.head() < u.head() || (!(t.head() < u.head()) && t.tail() < u.tail()));
237 }
238
239 template<typename... TValues, typename... UValues>
operator >(const tuple<TValues...> & t,const tuple<UValues...> & u)240 bool operator>(const tuple<TValues...>& t, const tuple<UValues...>& u) {
241 return u < t;
242 }
243
244 template<typename... TValues, typename... UValues>
operator <=(const tuple<TValues...> & t,const tuple<UValues...> & u)245 bool operator<=(const tuple<TValues...>& t, const tuple<UValues...>& u) {
246 return !(u < t);
247 }
248
249 template<typename... TValues, typename... UValues>
operator >=(const tuple<TValues...> & t,const tuple<UValues...> & u)250 bool operator>=(const tuple<TValues...>& t, const tuple<UValues...>& u) {
251 return !(t < u);
252 }
253
test_relational_operators(tuple<int *,float *,double * > t3)254 void test_relational_operators(tuple<int*, float*, double*> t3) {
255 (void)(t3 == t3);
256 (void)(t3 != t3);
257 (void)(t3 < t3);
258 (void)(t3 <= t3);
259 (void)(t3 >= t3);
260 (void)(t3 > t3);
261 };
262