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1 // RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
2 
3 // Example tuple implementation from the variadic templates proposal,
4 // ISO C++ committee document number N2080.
5 
6 // Helper type traits
7 template<typename T>
8 struct add_reference {
9   typedef T &type;
10 };
11 
12 template<typename T>
13 struct add_reference<T&> {
14   typedef T &type;
15 };
16 
17 template<typename T>
18 struct add_const_reference {
19   typedef T const &type;
20 };
21 
22 template<typename T>
23 struct add_const_reference<T&> {
24   typedef T &type;
25 };
26 
27 template<typename T, typename U>
28 struct is_same {
29   static const bool value = false;
30 };
31 
32 template<typename T>
33 struct is_same<T, T> {
34   static const bool value = true;
35 };
36 
37 template<typename T>
38 class reference_wrapper {
39   T *ptr;
40 
41 public:
reference_wrapper(T & t)42   reference_wrapper(T& t) : ptr(&t) { }
operator T&() const43   operator T&() const { return *ptr; }
44 };
45 
ref(T & t)46 template<typename T> reference_wrapper<T> ref(T& t) {
47   return reference_wrapper<T>(t);
48 }
cref(const T & t)49 template<typename T> reference_wrapper<const T> cref(const T& t) {
50   return reference_wrapper<const T>(t);
51 }
52 
53 template<typename... Values> class tuple;
54 
55 // Basis case: zero-length tuple
56 template<> class tuple<> { };
57 
58 template<typename Head, typename... Tail>
59 class tuple<Head, Tail...> : private tuple<Tail...> {
60   typedef tuple<Tail...> inherited;
61 
62 public:
tuple()63   tuple() { }
64   // implicit copy-constructor is okay
65 
66   // Construct tuple from separate arguments.
tuple(typename add_const_reference<Head>::type v,typename add_const_reference<Tail>::type...vtail)67   tuple(typename add_const_reference<Head>::type v,
68         typename add_const_reference<Tail>::type... vtail)
69     : m_head(v), inherited(vtail...) { }
70 
71   // Construct tuple from another tuple.
tuple(const tuple<VValues...> & other)72   template<typename... VValues> tuple(const tuple<VValues...>& other)
73     : m_head(other.head()), inherited(other.tail()) { }
74 
75   template<typename... VValues> tuple&
operator =(const tuple<VValues...> & other)76   operator=(const tuple<VValues...>& other) {
77     m_head = other.head();
78     tail() = other.tail();
79     return *this;
80   }
81 
head()82   typename add_reference<Head>::type head() { return m_head; }
head() const83   typename add_reference<const Head>::type head() const { return m_head; }
tail()84   inherited& tail() { return *this; }
tail() const85   const inherited& tail() const { return *this; }
86 
87 protected:
88   Head m_head;
89 };
90 
test_tuple()91 void test_tuple() {
92   tuple<> t0a;
93   tuple<> t0b(t0a);
94   t0a = t0b;
95 
96   tuple<int> t1a;
97   tuple<int> t1b(17);
98   tuple<int> t1c(t1b);
99   t1a = t1b;
100 
101   tuple<float> t1d(3.14159);
102   tuple<float> t1e(t1d);
103   t1d = t1e;
104 
105   int i;
106   float f;
107   double d;
108   tuple<int*, float*, double*> t3a(&i, &f, &d);
109 }
110 
111 // Creation functions
112 template<typename T>
113 struct make_tuple_result {
114   typedef T type;
115 };
116 
117 template<typename T>
118 struct make_tuple_result<reference_wrapper<T> > {
119   typedef T& type;
120 };
121 
122 template<typename... Values>
123 tuple<typename make_tuple_result<Values>::type...>
make_tuple(const Values &...values)124 make_tuple(const Values&... values) {
125   return tuple<typename make_tuple_result<Values>::type...>(values...);
126 }
127 
128 template<typename... Values>
tie(Values &...values)129 tuple<Values&...> tie(Values&... values) {
130   return tuple<Values&...>(values...);
131 }
132 
addr(const T & ref)133 template<typename T> const T *addr(const T& ref) { return &ref; }
test_creation_functions()134 void test_creation_functions() {
135   int i;
136   float f;
137   double d;
138   const tuple<int, float&, const double&> *t3p = addr(make_tuple(i, ref(f), cref(d)));
139   const tuple<int&, float&, double&> *t3q = addr(tie(i, f, d));
140 }
141 
142 // Helper classes
143 template<typename Tuple> struct tuple_size;
144 
145 template<typename... Values> struct tuple_size<tuple<Values...> > {
146   static const int value = sizeof...(Values);
147 };
148 
149 int check_tuple_size_0[tuple_size<tuple<> >::value == 0? 1 : -1];
150 int check_tuple_size_1[tuple_size<tuple<int>>::value == 1? 1 : -1];
151 int check_tuple_size_2[tuple_size<tuple<float, double>>::value == 2? 1 : -1];
152 int check_tuple_size_3[tuple_size<tuple<char, unsigned char, signed char>>::value == 3? 1 : -1];
153 
154 template<int I, typename Tuple> struct tuple_element;
155 
156 template<int I, typename Head, typename... Tail>
157 struct tuple_element<I, tuple<Head, Tail...> > {
158   typedef typename tuple_element<I-1, tuple<Tail...> >::type type;
159 };
160 
161 template<typename Head, typename... Tail>
162 struct tuple_element<0, tuple<Head, Tail...> > {
163   typedef Head type;
164 };
165 
166 int check_tuple_element_0[is_same<tuple_element<0, tuple<int&, float, double>>::type,
167                                   int&>::value? 1 : -1];
168 
169 int check_tuple_element_1[is_same<tuple_element<1, tuple<int&, float, double>>::type,
170                                   float>::value? 1 : -1];
171 
172 int check_tuple_element_2[is_same<tuple_element<2, tuple<int&, float, double>>::type,
173                                   double>::value? 1 : -1];
174 
175 // Element access
176 template<int I, typename Tuple> class get_impl;
177 template<int I, typename Head, typename... Values>
178 class get_impl<I, tuple<Head, Values...> > {
179   typedef typename tuple_element<I-1, tuple<Values...> >::type Element;
180   typedef typename add_reference<Element>::type RJ;
181   typedef typename add_const_reference<Element>::type PJ;
182   typedef get_impl<I-1, tuple<Values...> > Next;
183 public:
get(tuple<Head,Values...> & t)184   static RJ get(tuple<Head, Values...>& t) { return Next::get(t.tail()); }
get(const tuple<Head,Values...> & t)185   static PJ get(const tuple<Head, Values...>& t) { return Next::get(t.tail()); }
186 };
187 
188 template<typename Head, typename... Values>
189 class get_impl<0, tuple<Head, Values...> > {
190   typedef typename add_reference<Head>::type RJ;
191   typedef typename add_const_reference<Head>::type PJ;
192 public:
get(tuple<Head,Values...> & t)193   static RJ get(tuple<Head, Values...>& t) { return t.head(); }
get(const tuple<Head,Values...> & t)194   static PJ get(const tuple<Head, Values...>& t) { return t.head(); }
195 };
196 
197 template<int I, typename... Values> typename add_reference<
198 typename tuple_element<I, tuple<Values...> >::type >::type
get(tuple<Values...> & t)199 get(tuple<Values...>& t) {
200   return get_impl<I, tuple<Values...> >::get(t);
201 }
202 
203 template<int I, typename... Values> typename add_const_reference<
204 typename tuple_element<I, tuple<Values...> >::type >::type
get(const tuple<Values...> & t)205 get(const tuple<Values...>& t) {
206   return get_impl<I, tuple<Values...> >::get(t);
207 }
208 
test_element_access(tuple<int *,float *,double * &> t3)209 void test_element_access(tuple<int*, float*, double*&> t3) {
210   int i;
211   float f;
212   double d;
213   get<0>(t3) = &i;
214   get<1>(t3) = &f;
215   get<2>(t3) = &d;
216 }
217 
218 // Relational operators
operator ==(const tuple<> &,const tuple<> &)219 inline bool operator==(const tuple<>&, const tuple<>&) { return true; }
220 
221 template<typename T, typename... TTail, typename U, typename... UTail>
operator ==(const tuple<T,TTail...> & t,const tuple<U,UTail...> & u)222 bool operator==(const tuple<T, TTail...>& t, const tuple<U, UTail...>& u) {
223   return t.head() == u.head() && t.tail() == u.tail();
224 }
225 
226 template<typename... TValues, typename... UValues>
operator !=(const tuple<TValues...> & t,const tuple<UValues...> & u)227 bool operator!=(const tuple<TValues...>& t, const tuple<UValues...>& u) {
228   return !(t == u);
229 }
230 
operator <(const tuple<> &,const tuple<> &)231 inline bool operator<(const tuple<>&, const tuple<>&) { return false; }
232 
233 template<typename T, typename... TTail, typename U, typename... UTail>
operator <(const tuple<T,TTail...> & t,const tuple<U,UTail...> & u)234 bool operator<(const tuple<T, TTail...>& t, const tuple<U, UTail...>& u) {
235   return (t.head() < u.head() || (!(t.head() < u.head()) && t.tail() < u.tail()));
236 }
237 
238 template<typename... TValues, typename... UValues>
operator >(const tuple<TValues...> & t,const tuple<UValues...> & u)239 bool operator>(const tuple<TValues...>& t, const tuple<UValues...>& u) {
240   return u < t;
241 }
242 
243 template<typename... TValues, typename... UValues>
operator <=(const tuple<TValues...> & t,const tuple<UValues...> & u)244 bool operator<=(const tuple<TValues...>& t, const tuple<UValues...>& u) {
245   return !(u < t);
246 }
247 
248 template<typename... TValues, typename... UValues>
operator >=(const tuple<TValues...> & t,const tuple<UValues...> & u)249 bool operator>=(const tuple<TValues...>& t, const tuple<UValues...>& u) {
250   return !(t < u);
251 }
252 
test_relational_operators(tuple<int *,float *,double * > t3)253 void test_relational_operators(tuple<int*, float*, double*> t3) {
254   (void)(t3 == t3);
255   (void)(t3 != t3);
256   (void)(t3 < t3);
257   (void)(t3 <= t3);
258   (void)(t3 >= t3);
259   (void)(t3 > t3);
260 };
261