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: 42 reference_wrapper(T& t) : ptr(&t) { } 43 operator T&() const { return *ptr; } 44 }; 45 46 template<typename T> reference_wrapper<T> ref(T& t) { 47 return reference_wrapper<T>(t); 48 } 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: 63 tuple() { } 64 // implicit copy-constructor is okay 65 66 // Construct tuple from separate arguments. 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. 72 template<typename... VValues> tuple(const tuple<VValues...>& other) 73 : m_head(other.head()), inherited(other.tail()) { } 74 75 template<typename... VValues> tuple& 76 operator=(const tuple<VValues...>& other) { 77 m_head = other.head(); 78 tail() = other.tail(); 79 return *this; 80 } 81 82 typename add_reference<Head>::type head() { return m_head; } 83 typename add_reference<const Head>::type head() const { return m_head; } 84 inherited& tail() { return *this; } 85 const inherited& tail() const { return *this; } 86 87 protected: 88 Head m_head; 89 }; 90 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...> 124 make_tuple(const Values&... values) { 125 return tuple<typename make_tuple_result<Values>::type...>(values...); 126 } 127 128 template<typename... Values> 129 tuple<Values&...> tie(Values&... values) { 130 return tuple<Values&...>(values...); 131 } 132 133 template<typename T> const T *addr(const T& ref) { return &ref; } 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: 184 static RJ get(tuple<Head, Values...>& t) { return Next::get(t.tail()); } 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: 193 static RJ get(tuple<Head, Values...>& t) { return t.head(); } 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 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 205 get(const tuple<Values...>& t) { 206 return get_impl<I, tuple<Values...> >::get(t); 207 } 208 209 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 219 inline bool operator==(const tuple<>&, const tuple<>&) { return true; } 220 221 template<typename T, typename... TTail, typename U, typename... UTail> 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> 227 bool operator!=(const tuple<TValues...>& t, const tuple<UValues...>& u) { 228 return !(t == u); 229 } 230 231 inline bool operator<(const tuple<>&, const tuple<>&) { return false; } 232 233 template<typename T, typename... TTail, typename U, typename... UTail> 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> 239 bool operator>(const tuple<TValues...>& t, const tuple<UValues...>& u) { 240 return u < t; 241 } 242 243 template<typename... TValues, typename... UValues> 244 bool operator<=(const tuple<TValues...>& t, const tuple<UValues...>& u) { 245 return !(u < t); 246 } 247 248 template<typename... TValues, typename... UValues> 249 bool operator>=(const tuple<TValues...>& t, const tuple<UValues...>& u) { 250 return !(t < u); 251 } 252 253 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
