1 // RUN: %clang_cc1 -fcxx-exceptions -fexceptions -std=c++11 -fblocks -fms-extensions -fsyntax-only -verify %s 2 3 template<typename T, typename U> struct pair; 4 template<typename ...> struct tuple; 5 6 // A parameter pack whose name appears within the pattern of a pack 7 // expansion is expanded by that pack expansion. An appearance of the 8 // name of a parameter pack is only expanded by the innermost 9 // enclosing pack expansion. The pattern of a pack expansion shall 10 // name one or more parameter packs that are not expanded by a nested 11 // pack expansion. 12 template<typename... Types> 13 struct Expansion { 14 typedef pair<Types..., int> expand_with_pacs; // okay 15 typedef pair<Types, int...> expand_no_packs; // expected-error{{pack expansion does not contain any unexpanded parameter packs}} 16 typedef pair<pair<Types..., int>..., int> expand_with_expanded_nested; // expected-error{{pack expansion does not contain any unexpanded parameter packs}} 17 }; 18 19 // All of the parameter packs expanded by a pack expansion shall have 20 // the same number of arguments specified. 21 template<typename ...Types> 22 struct ExpansionLengthMismatch { 23 template<typename ...OtherTypes> 24 struct Inner { 25 typedef tuple<pair<Types, OtherTypes>...> type; // expected-error{{pack expansion contains parameter packs 'Types' and 'OtherTypes' that have different lengths (3 vs. 2)}} 26 }; 27 }; 28 29 ExpansionLengthMismatch<int, long>::Inner<unsigned int, unsigned long>::type 30 *il_pairs; 31 tuple<pair<int, unsigned int>, pair<long, unsigned long> >*il_pairs_2 = il_pairs; 32 33 ExpansionLengthMismatch<short, int, long>::Inner<unsigned int, unsigned long>::type // expected-note{{in instantiation of template class 'ExpansionLengthMismatch<short, int, long>::Inner<unsigned int, unsigned long>' requested here}} 34 *il_pairs_bad; 35 36 37 // An appearance of a name of a parameter pack that is not expanded is 38 // ill-formed. 39 40 // Test for unexpanded parameter packs in each of the type nodes. 41 template<typename T, int N, typename ... Types> 42 struct TestPPName 43 : public Types, public T // expected-error{{base type contains unexpanded parameter pack 'Types'}} 44 { 45 // BuiltinType is uninteresting 46 // FIXME: ComplexType is uninteresting? 47 // PointerType 48 typedef Types *types_pointer; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 49 50 // BlockPointerType 51 typedef Types (^block_pointer_1)(int); // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 52 typedef int (^block_pointer_2)(Types); // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 53 54 // LValueReferenceType 55 typedef Types &lvalue_ref; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 56 57 // RValueReferenceType 58 typedef Types &&rvalue_ref; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 59 60 // MemberPointerType 61 typedef Types TestPPName::* member_pointer_1; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 62 typedef int Types::*member_pointer_2; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 63 64 // ConstantArrayType 65 typedef Types constant_array[17]; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 66 67 // IncompleteArrayType 68 typedef Types incomplete_array[]; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 69 70 // VariableArrayType 71 void f(int i) { 72 Types variable_array[i]; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 73 } 74 75 // DependentSizedArrayType 76 typedef Types dependent_sized_array[N]; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 77 78 // DependentSizedExtVectorType 79 typedef Types dependent_sized_ext_vector __attribute__((ext_vector_type(N))); // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 80 81 // VectorType is uninteresting 82 83 // ExtVectorType 84 typedef Types ext_vector __attribute__((ext_vector_type(4))); // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 85 86 // FunctionProtoType 87 typedef Types (function_type_1)(int); // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 88 typedef int (function_type_2)(Types); // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 89 90 // FunctionNoProtoType is uninteresting 91 // UnresolvedUsingType is uninteresting 92 // ParenType is uninteresting 93 // TypedefType is uninteresting 94 95 // TypeOfExprType 96 typedef __typeof__((static_cast<Types>(0))) typeof_expr; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 97 98 // TypeOfType 99 typedef __typeof__(Types) typeof_type; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 100 101 // DecltypeType 102 typedef decltype((static_cast<Types>(0))) typeof_expr; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 103 104 // RecordType is uninteresting 105 // EnumType is uninteresting 106 // ElaboratedType is uninteresting 107 108 // TemplateTypeParmType 109 typedef Types template_type_parm; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 110 111 // SubstTemplateTypeParmType is uninteresting 112 113 // TemplateSpecializationType 114 typedef pair<Types, int> template_specialization; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 115 116 // InjectedClassName is uninteresting. 117 118 // DependentNameType 119 typedef typename Types::type dependent_name; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 120 121 // DependentTemplateSpecializationType 122 typedef typename Types::template apply<int> dependent_name_1; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 123 typedef typename T::template apply<Types> dependent_name_2; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 124 125 // ObjCObjectType is uninteresting 126 // ObjCInterfaceType is uninteresting 127 // ObjCObjectPointerType is uninteresting 128 }; 129 130 // FIXME: Test for unexpanded parameter packs in each of the expression nodes. 131 template<int ...Values> 132 void test_unexpanded_in_exprs() { 133 // PredefinedExpr is uninteresting 134 // DeclRefExpr 135 Values; // expected-error{{expression contains unexpanded parameter pack 'Values'}} 136 // IntegerLiteral is uninteresting 137 // FloatingLiteral is uninteresting 138 // ImaginaryLiteral is uninteresting 139 // StringLiteral is uninteresting 140 // CharacterLiteral is uninteresting 141 (Values); // expected-error{{expression contains unexpanded parameter pack 'Values'}} 142 // UnaryOperator 143 -Values; // expected-error{{expression contains unexpanded parameter pack 'Values'}} 144 // OffsetOfExpr 145 struct OffsetMe { 146 int array[17]; 147 }; 148 __builtin_offsetof(OffsetMe, array[Values]); // expected-error{{expression contains unexpanded parameter pack 'Values'}} 149 // FIXME: continue this... 150 } 151 152 template<typename ... Types> 153 void TestPPNameFunc(int i) { 154 f(static_cast<Types>(i)); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 155 } 156 157 template<typename T, template<class> class ...Meta> 158 struct TestUnexpandedTTP { 159 typedef tuple<typename Meta<T>::type> type; // expected-error{{declaration type contains unexpanded parameter pack 'Meta'}} 160 }; 161 162 // Test for unexpanded parameter packs in declarations. 163 template<typename T, typename... Types> 164 // FIXME: this should test that the diagnostic reads "type contains..." 165 struct alignas(Types) TestUnexpandedDecls : T{ // expected-error{{expression contains unexpanded parameter pack 'Types'}} 166 void member_function(Types); // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 167 void member_function () throw(Types); // expected-error{{exception type contains unexpanded parameter pack 'Types'}} 168 void member_function2() noexcept(Types()); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 169 operator Types() const; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 170 Types data_member; // expected-error{{data member type contains unexpanded parameter pack 'Types'}} 171 static Types static_data_member; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 172 unsigned bit_field : static_cast<Types>(0); // expected-error{{bit-field size contains unexpanded parameter pack 'Types'}} 173 static_assert(static_cast<Types>(0), "Boom"); // expected-error{{static assertion contains unexpanded parameter pack 'Types'}} 174 175 enum E0 : Types { // expected-error{{fixed underlying type contains unexpanded parameter pack 'Types'}} 176 EnumValue = static_cast<Types>(0) // expected-error{{enumerator value contains unexpanded parameter pack 'Types'}} 177 }; 178 179 using typename Types::type; // expected-error{{using declaration contains unexpanded parameter pack 'Types'}} 180 using Types::value; // expected-error{{using declaration contains unexpanded parameter pack 'Types'}} 181 using T::operator Types; // expected-error{{using declaration contains unexpanded parameter pack 'Types'}} 182 183 friend class Types::foo; // expected-error{{friend declaration contains unexpanded parameter pack 'Types'}} 184 friend void friend_func(Types); // expected-error{{friend declaration contains unexpanded parameter pack 'Types'}} 185 friend void Types::other_friend_func(int); // expected-error{{friend declaration contains unexpanded parameter pack 'Types'}} 186 187 void test_initializers() { 188 T copy_init = static_cast<Types>(0); // expected-error{{initializer contains unexpanded parameter pack 'Types'}} 189 T direct_init(0, static_cast<Types>(0)); // expected-error{{initializer contains unexpanded parameter pack 'Types'}} 190 T list_init = { static_cast<Types>(0) }; // expected-error{{initializer contains unexpanded parameter pack 'Types'}} 191 } 192 193 T in_class_member_init = static_cast<Types>(0); // expected-error{{initializer contains unexpanded parameter pack 'Types'}} 194 TestUnexpandedDecls() : 195 Types(static_cast<Types>(0)), // expected-error{{initializer contains unexpanded parameter pack 'Types'}} 196 Types(static_cast<Types>(0))..., 197 in_class_member_init(static_cast<Types>(0)) {} // expected-error{{initializer contains unexpanded parameter pack 'Types'}} 198 199 void default_function_args(T = static_cast<Types>(0)); // expected-error{{default argument contains unexpanded parameter pack 'Types'}} 200 201 template<typename = Types*> // expected-error{{default argument contains unexpanded parameter pack 'Types'}} 202 struct default_template_args_1; 203 template<int = static_cast<Types>(0)> // expected-error{{default argument contains unexpanded parameter pack 'Types'}} 204 struct default_template_args_2; 205 template<template<typename> class = Types::template apply> // expected-error{{default argument contains unexpanded parameter pack 'Types'}} 206 struct default_template_args_3; 207 208 template<Types value> // expected-error{{non-type template parameter type contains unexpanded parameter pack 'Types'}} 209 struct non_type_template_param_type; 210 211 void decls_in_stmts() { 212 Types t; // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 213 for (Types *t = 0; ; ) { } // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 214 for (; Types *t = 0; ) { } // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 215 T a[] = { T(), T(), T() }; 216 for (Types t : a) { } // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 217 switch(Types *t = 0) { } // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 218 while(Types *t = 0) { } // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 219 if (Types *t = 0) { } // expected-error{{declaration type contains unexpanded parameter pack 'Types'}} 220 try { 221 } catch (Types*) { // expected-error{{exception type contains unexpanded parameter pack 'Types'}} 222 } 223 } 224 }; 225 226 // FIXME: Test for unexpanded parameter packs in each of the statements. 227 struct X { 228 void f(int, int); 229 template<typename ...Types> 230 void f(Types...); 231 }; 232 233 namespace std { 234 class type_info; 235 } 236 237 typedef struct _GUID { 238 unsigned long Data1; 239 unsigned short Data2; 240 unsigned short Data3; 241 unsigned char Data4[ 8 ]; 242 } GUID; 243 244 template<typename T, typename ...Types> 245 void test_unexpanded_exprs(Types ...values) { 246 // CXXOperatorCallExpr 247 (void)(values + 0); // expected-error{{expression contains unexpanded parameter pack 'values'}} 248 (void)(0 + values); // expected-error{{expression contains unexpanded parameter pack 'values'}} 249 250 // CXXMemberCallExpr 251 values.f(); // expected-error{{expression contains unexpanded parameter pack 'values'}} 252 X x; 253 x.f(values); // expected-error{{expression contains unexpanded parameter pack 'values'}} 254 x.Types::f(); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 255 x.f<Types>(); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 256 257 // CXXStaticCastExpr 258 (void)static_cast<Types&>(values); // expected-error{{expression contains unexpanded parameter packs 'Types' and 'values'}} 259 260 // CXXDynamicCastExpr 261 (void)dynamic_cast<Types&>(values); // expected-error{{expression contains unexpanded parameter packs 'Types' and 'values'}} 262 263 // CXXReinterpretCastExpr 264 (void)reinterpret_cast<Types&>(values); // expected-error{{expression contains unexpanded parameter packs 'Types' and 'values'}} 265 266 // CXXConstCastExpr 267 (void)const_cast<Types&>(values); // expected-error{{expression contains unexpanded parameter packs 'Types' and 'values'}} 268 269 // CXXTypeidExpr 270 (void)typeid(Types); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 271 (void)typeid(values); // expected-error{{expression contains unexpanded parameter pack 'values'}} 272 273 // CXXUuidofExpr 274 (void)__uuidof(Types); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 275 (void)__uuidof(values); // expected-error{{expression contains unexpanded parameter pack 'values'}} 276 277 // CXXThisExpr is uninteresting 278 279 // CXXThrowExpr 280 throw Types(); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 281 throw values; // expected-error{{expression contains unexpanded parameter pack 'values'}} 282 283 // CXXDefaultArgExpr is uninteresting 284 285 // CXXBindTemporaryExpr is uninteresting 286 287 // CXXConstructExpr is uninteresting 288 289 // CXXFunctionalCastExpr 290 (void)Types(); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 291 292 // CXXTemporaryObjectExpr 293 (void)X(values); // expected-error{{expression contains unexpanded parameter pack 'values'}} 294 295 // CXXScalarValueInitExpr is uninteresting 296 297 // CXXNewExpr 298 (void)new Types; // expected-error{{expression contains unexpanded parameter pack 'Types'}} 299 (void)new X(values); // expected-error{{expression contains unexpanded parameter pack 'values'}} 300 (void)new (values) X(values); // expected-error{{expression contains unexpanded parameter pack 'values'}} 301 (void)new X [values]; // expected-error{{expression contains unexpanded parameter pack 'values'}} 302 303 // CXXDeleteExpr 304 delete values; // expected-error{{expression contains unexpanded parameter pack 'values'}} 305 delete [] values; // expected-error{{expression contains unexpanded parameter pack 'values'}} 306 307 // CXXPseudoDestructorExpr 308 T t; 309 values.~T(); // expected-error{{expression contains unexpanded parameter pack 'values'}} 310 t.~Types(); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 311 t.Types::~T(); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 312 313 // Unary TypeTraitExpr 314 __is_pod(Types); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 315 316 // Binary TypeTraitExpr 317 __is_base_of(Types, T); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 318 __is_base_of(T, Types); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 319 320 // UnresolvedLookupExpr 321 test_unexpanded_exprs(values); // expected-error{{expression contains unexpanded parameter pack 'values'}} 322 test_unexpanded_exprs<Types>(); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 323 324 // DependentScopeDeclRefExpr 325 Types::test_unexpanded_exprs(); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 326 T::template test_unexpanded_exprs<Types>(); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 327 328 // CXXUnresolvedConstructExpr 329 Types(5); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 330 331 // CXXDependentScopeMemberExpr 332 values.foo(); // expected-error{{expression contains unexpanded parameter pack 'values'}} 333 t.foo(values); // expected-error{{expression contains unexpanded parameter pack 'values'}} 334 335 // FIXME: There's an evil ambiguity here, because we don't know if 336 // Types refers to the template type parameter pack in scope or a 337 // non-pack member. 338 // t.Types::foo(); 339 340 t.template foo<Types>(); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 341 342 // UnresolvedMemberExpr 343 x.f<Types>(); // expected-error{{expression contains unexpanded parameter pack 'Types'}} 344 x.f(values); // expected-error{{expression contains unexpanded parameter pack 'values'}} 345 346 // CXXNoexceptExpr 347 noexcept(values); // expected-error{{expression contains unexpanded parameter pack 'values'}} 348 349 // PackExpansionExpr is uninteresting 350 // SizeOfPackExpr is uninteresting 351 352 // FIXME: Objective-C expressions will need to go elsewhere 353 354 for (auto t : values) { } // expected-error{{expression contains unexpanded parameter pack 'values'}} 355 356 switch (values) { } // expected-error{{expression contains unexpanded parameter pack 'values'}} 357 switch (0) { case 0: case values: ; } // expected-error{{expression contains unexpanded parameter pack 'values'}} 358 359 do { } while (values); // expected-error{{expression contains unexpanded parameter pack 'values'}} 360 361 test: 362 goto *values; // expected-error{{expression contains unexpanded parameter pack 'values'}} 363 364 void f(int arg = values); // expected-error{{default argument contains unexpanded parameter pack 'values'}} 365 } 366 367 // Test unexpanded parameter packs in partial specializations. 368 template<typename ...Types> 369 struct TestUnexpandedDecls<int, Types>; // expected-error{{partial specialization contains unexpanded parameter pack 'Types'}} 370 371 // Test for diagnostics in the presence of multiple unexpanded 372 // parameter packs. 373 template<typename T, typename U> struct pair; 374 375 template<typename ...OuterTypes> 376 struct MemberTemplatePPNames { 377 template<typename ...InnerTypes> 378 struct Inner { 379 typedef pair<OuterTypes, InnerTypes>* types; // expected-error{{declaration type contains unexpanded parameter packs 'OuterTypes' and 'InnerTypes'}} 380 381 template<typename ...VeryInnerTypes> 382 struct VeryInner { 383 typedef pair<pair<VeryInnerTypes, OuterTypes>, pair<InnerTypes, OuterTypes> > types; // expected-error{{declaration type contains unexpanded parameter packs 'VeryInnerTypes', 'OuterTypes', ...}} 384 }; 385 }; 386 }; 387 388 // Example from working paper 389 namespace WorkingPaperExample { 390 template<typename...> struct Tuple {}; 391 template<typename T1, typename T2> struct Pair {}; 392 393 template<class ... Args1> struct zip { 394 template<class ... Args2> struct with { 395 typedef Tuple<Pair<Args1, Args2> ... > type; // expected-error{{pack expansion contains parameter packs 'Args1' and 'Args2' that have different lengths (1 vs. 2)}} 396 }; 397 }; 398 399 typedef zip<short, int>::with<unsigned short, unsigned>::type T1; // T1 is Tuple<Pair<short, unsigned short>, Pair<int, unsigned>> 400 typedef Tuple<Pair<short, unsigned short>, Pair<int, unsigned>> T1; 401 402 typedef zip<short>::with<unsigned short, unsigned>::type T2; // expected-note{{in instantiation of template class}} 403 404 template<class ... Args> void f(Args...); 405 template<class ... Args> void h(Args...); 406 407 template<class ... Args> 408 void g(Args ... args) { 409 f(const_cast<const Args*>(&args)...); // OK: "Args" and "args" are expanded within f 410 f(5 ...); // expected-error{{pack expansion does not contain any unexpanded parameter packs}} 411 f(args); // expected-error{{expression contains unexpanded parameter pack 'args'}} 412 f(h(args ...) + args ...); 413 } 414 } 415 416 namespace PR16303 { 417 template<int> struct A { A(int); }; 418 template<int...N> struct B { 419 template<int...M> struct C : A<N>... { 420 C() : A<N>(M)... {} // expected-error{{pack expansion contains parameter packs 'N' and 'M' that have different lengths (2 vs. 3)}} expected-error{{pack expansion contains parameter packs 'N' and 'M' that have different lengths (4 vs. 3)}} 421 }; 422 }; 423 B<1,2>::C<4,5,6> c1; // expected-note{{in instantiation of}} 424 B<1,2,3,4>::C<4,5,6> c2; // expected-note{{in instantiation of}} 425 } 426 427 namespace PR21289 { 428 template<int> using T = int; 429 template<typename> struct S { static const int value = 0; }; 430 template<typename> const int vt = 0; // expected-warning {{extension}} 431 int f(...); 432 template<int ...Ns> void g() { 433 f(T<Ns>()...); 434 f(S<T<Ns>>::value...); 435 f(vt<T<Ns>>...); 436 } 437 template void g<>(); 438 template void g<1, 2, 3>(); 439 } 440 441 template <class... Ts> 442 int var_expr(Ts... ts); 443 444 template <class... Ts> 445 auto a_function(Ts... ts) -> decltype(var_expr(ts...)); 446 447 template <class T> 448 using partial = decltype(a_function<int, T>); 449 450 int use_partial() { partial<char> n; } 451 452 namespace PR26017 { 453 template <class T> 454 struct Foo {}; 455 template <class... Ts> 456 using FooAlias = Foo<void(Ts...)>; 457 458 template <class... Ts> 459 using FooAliasAlias = FooAlias<Ts..., Ts...>; 460 461 template <class... Ts> 462 void bar(const FooAlias<Ts...> &) {} 463 464 int fn() { 465 FooAlias<> a; 466 bar(a); 467 468 FooAlias<int> b; 469 bar(b); 470 } 471 } 472
