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