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: 43 reference_wrapper(T& t) : ptr(&t) { } 44 operator T&() const { return *ptr; } 45 }; 46 47 template<typename T> reference_wrapper<T> ref(T& t) { 48 return reference_wrapper<T>(t); 49 } 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: 64 tuple() { } 65 // implicit copy-constructor is okay 66 67 // Construct tuple from separate arguments. 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. 73 template<typename... VValues> tuple(const tuple<VValues...>& other) 74 : m_head(other.head()), inherited(other.tail()) { } 75 76 template<typename... VValues> tuple& 77 operator=(const tuple<VValues...>& other) { 78 m_head = other.head(); 79 tail() = other.tail(); 80 return *this; 81 } 82 83 typename add_reference<Head>::type head() { return m_head; } 84 typename add_reference<const Head>::type head() const { return m_head; } 85 inherited& tail() { return *this; } 86 const inherited& tail() const { return *this; } 87 88 protected: 89 Head m_head; 90 }; 91 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...> 125 make_tuple(const Values&... values) { 126 return tuple<typename make_tuple_result<Values>::type...>(values...); 127 } 128 129 template<typename... Values> 130 tuple<Values&...> tie(Values&... values) { 131 return tuple<Values&...>(values...); 132 } 133 134 template<typename T> const T *addr(const T& ref) { return &ref; } 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: 185 static RJ get(tuple<Head, Values...>& t) { return Next::get(t.tail()); } 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: 194 static RJ get(tuple<Head, Values...>& t) { return t.head(); } 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 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 206 get(const tuple<Values...>& t) { 207 return get_impl<I, tuple<Values...> >::get(t); 208 } 209 210 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 220 inline bool operator==(const tuple<>&, const tuple<>&) { return true; } 221 222 template<typename T, typename... TTail, typename U, typename... UTail> 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> 228 bool operator!=(const tuple<TValues...>& t, const tuple<UValues...>& u) { 229 return !(t == u); 230 } 231 232 inline bool operator<(const tuple<>&, const tuple<>&) { return false; } 233 234 template<typename T, typename... TTail, typename U, typename... UTail> 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> 240 bool operator>(const tuple<TValues...>& t, const tuple<UValues...>& u) { 241 return u < t; 242 } 243 244 template<typename... TValues, typename... UValues> 245 bool operator<=(const tuple<TValues...>& t, const tuple<UValues...>& u) { 246 return !(u < t); 247 } 248 249 template<typename... TValues, typename... UValues> 250 bool operator>=(const tuple<TValues...>& t, const tuple<UValues...>& u) { 251 return !(t < u); 252 } 253 254 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