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