clang/test/SemaCXX/cxx0x-initializer-stdinitializerlist.cpp

   1 // RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
   2
   3 // This must obviously come before the definition of std::initializer_list.
   4 void missing_initializerlist() {
   5   auto l = {1, 2, 3, 4}; // expected-error {{std::initializer_list was not found}}
   6 }
   7
   8 namespace std {
   9   typedef decltype(sizeof(int)) size_t;
  10
  11   // libc++'s implementation
  12   template <class _E>
  13   class initializer_list
  14   {
  15     const _E* __begin_;
  16     size_t    __size_;
  17
  18     initializer_list(const _E* __b, size_t __s)
  19       : __begin_(__b),
  20         __size_(__s)
  21     {}
  22
  23   public:
  24     typedef _E        value_type;
  25     typedef const _E& reference;
  26     typedef const _E& const_reference;
  27     typedef size_t    size_type;
  28
  29     typedef const _E* iterator;
  30     typedef const _E* const_iterator;
  31
  32     constexpr initializer_list() : __begin_(nullptr), __size_(0) {}
  33
  34     constexpr size_t    size()  const {return __size_;}
  35     const _E* begin() const {return __begin_;}
  36     const _E* end()   const {return __begin_ + __size_;}
  37   };
  38 }
  39
  40 template <typename T, typename U>
  41 struct same_type { static const bool value = false; };
  42 template <typename T>
  43 struct same_type<T, T> { static const bool value = true; };
  44
  45 struct one { char c[1]; };
  46 struct two { char c[2]; };
  47
  48 struct A {
  49   int a, b;
  50 };
  51
  52 struct B {
  53   B();
  54   B(int, int);
  55 };
  56
  57 void simple_list() {
  58   std::initializer_list<int> il = { 1, 2, 3 };
  59   std::initializer_list<double> dl = { 1.0, 2.0, 3 };
  60   std::initializer_list<A> al = { {1, 2}, {2, 3}, {3, 4} };
  61   std::initializer_list<B> bl = { {1, 2}, {2, 3}, {} };
  62 }
  63
  64 void function_call() {
  65   void f(std::initializer_list<int>);
  66   f({1, 2, 3});
  67
  68   void g(std::initializer_list<B>);
  69   g({ {1, 2}, {2, 3}, {} });
  70 }
  71
  72 struct C {
  73   C(int);
  74 };
  75
  76 struct D {
  77   D();
  78   operator int();
  79   operator C();
  80 };
  81
  82 void overloaded_call() {
  83     one overloaded(std::initializer_list<int>);
  84     two overloaded(std::initializer_list<B>);
  85
  86     static_assert(sizeof(overloaded({1, 2, 3})) == sizeof(one), "bad overload");
  87     static_assert(sizeof(overloaded({ {1, 2}, {2, 3}, {} })) == sizeof(two), "bad overload");
  88
  89     void ambiguous(std::initializer_list<A>); // expected-note {{candidate}}
  90     void ambiguous(std::initializer_list<B>); // expected-note {{candidate}}
  91     ambiguous({ {1, 2}, {2, 3}, {3, 4} }); // expected-error {{ambiguous}}
  92
  93     one ov2(std::initializer_list<int>); // expected-note {{candidate}}
  94     two ov2(std::initializer_list<C>); // expected-note {{candidate}}
  95     // Worst sequence to int is identity, whereas to C it's user-defined.
  96     static_assert(sizeof(ov2({1, 2, 3})) == sizeof(one), "bad overload");
  97     // But here, user-defined is worst in both cases.
  98     ov2({1, 2, D()}); // expected-error {{ambiguous}}
  99 }
 100
 101 template <typename T>
 102 T deduce(std::initializer_list<T>); // expected-note {{conflicting types for parameter 'T' ('int' vs. 'double')}}
 103 template <typename T>
 104 T deduce_ref(const std::initializer_list<T>&); // expected-note {{conflicting types for parameter 'T' ('int' vs. 'double')}}
 105
 106 template<typename T, typename U> struct pair { pair(...); };
 107 template<typename T> void deduce_pairs(std::initializer_list<pair<T, typename T::type>>);
 108 // expected-note@-1 {{deduced type 'pair<[...], typename WithIntType::type>' of element of 1st parameter does not match adjusted type 'pair<[...], float>' of element of argument [with T = WithIntType]}}
 109 struct WithIntType { typedef int type; };
 110
 111 template<typename ...T> void deduce_after_init_list_in_pack(void (*)(T...), T...); // expected-note {{<int, int> vs. <(no value), double>}}
 112
 113 void argument_deduction() {
 114   static_assert(same_type<decltype(deduce({1, 2, 3})), int>::value, "bad deduction");
 115   static_assert(same_type<decltype(deduce({1.0, 2.0, 3.0})), double>::value, "bad deduction");
 116
 117   deduce({1, 2.0}); // expected-error {{no matching function}}
 118
 119   static_assert(same_type<decltype(deduce_ref({1, 2, 3})), int>::value, "bad deduction");
 120   static_assert(same_type<decltype(deduce_ref({1.0, 2.0, 3.0})), double>::value, "bad deduction");
 121
 122   deduce_ref({1, 2.0}); // expected-error {{no matching function}}
 123
 124   pair<WithIntType, int> pi;
 125   pair<WithIntType, float> pf;
 126   deduce_pairs({pi, pi, pi}); // ok
 127   deduce_pairs({pi, pf, pi}); // expected-error {{no matching function}}
 128
 129   deduce_after_init_list_in_pack((void(*)(int,int))0, {}, 0);
 130   deduce_after_init_list_in_pack((void(*)(int,int))0, {}, 0.0); // expected-error {{no matching function}}
 131 }
 132
 133 void auto_deduction() {
 134   auto l = {1, 2, 3, 4};
 135   auto l2 {1, 2, 3, 4}; // expected-error {{initializer for variable 'l2' with type 'auto' contains multiple expressions}}
 136   auto l3 {1};
 137   static_assert(same_type<decltype(l), std::initializer_list<int>>::value, "");
 138   static_assert(same_type<decltype(l3), int>::value, "");
 139   auto bl = {1, 2.0}; // expected-error {{deduced conflicting types ('int' vs 'double') for initializer list element type}}
 140
 141   void f1(int), f1(float), f2(int), f3(float);
 142   auto fil = {f1, f2};
 143   auto ffl = {f1, f3};
 144   auto fl = {f1, f2, f3}; // expected-error {{deduced conflicting types ('void (*)(int)' vs 'void (*)(float)') for initializer list element type}}
 145
 146   for (int i : {1, 2, 3, 4}) {}
 147   for (int j : {1.0, 2.0, 3.0f, 4.0}) {} // expected-error {{deduced conflicting types ('double' vs 'float') for initializer list element type}}
 148 }
 149
 150 void dangle() {
 151   new auto{1, 2, 3}; // expected-error {{new expression for type 'auto' contains multiple constructor arguments}}
 152   new std::initializer_list<int>{1, 2, 3}; // expected-warning {{at the end of the full-expression}}
 153 }
 154
 155 struct haslist1 {
 156   std::initializer_list<int> il // expected-note {{declared here}}
 157     = {1, 2, 3}; // ok, unused
 158   std::initializer_list<int> jl{1, 2, 3}; // expected-note {{default member init}}
 159   haslist1();
 160 };
 161
 162 haslist1::haslist1() // expected-error {{backing array for 'std::initializer_list' member 'jl' is a temporary object}}
 163 : il{1, 2, 3} // expected-error {{backing array for 'std::initializer_list' member 'il' is a temporary object}}
 164 {}
 165
 166 namespace PR12119 {
 167   // Deduction with nested initializer lists.
 168   template<typename T> void f(std::initializer_list<T>);
 169   template<typename T> void g(std::initializer_list<std::initializer_list<T>>);
 170
 171   void foo() {
 172     f({0, {1}}); // expected-warning{{braces around scalar initializer}}
 173     g({{0, 1}, {2, 3}});
 174     std::initializer_list<int> il = {1, 2};
 175     g({il, {2, 3}});
 176   }
 177 }
 178
 179 namespace Decay {
 180   template<typename T>
 181   void f(std::initializer_list<T>) {
 182     T x = 1; // expected-error{{cannot initialize a variable of type 'const char *' with an rvalue of type 'int'}}
 183   }
 184
 185   void g() {
 186     f({"A", "BB", "CCC"}); // expected-note{{in instantiation of function template specialization 'Decay::f<const char *>' requested here}}
 187
 188     auto x = { "A", "BB", "CCC" };
 189     std::initializer_list<const char *> *il = &x;
 190
 191     for( auto s : {"A", "BB", "CCC", "DDD"}) { }
 192   }
 193 }
 194
 195 namespace PR12436 {
 196   struct X {
 197     template<typename T>
 198     X(std::initializer_list<int>, T);
 199   };
 200
 201   X x({}, 17);
 202 }
 203
 204 namespace rdar11948732 {
 205   template<typename T> struct X {};
 206
 207   struct XCtorInit {
 208     XCtorInit(std::initializer_list<X<int>>);
 209   };
 210
 211   void f(X<int> &xi) {
 212     XCtorInit xc = { xi, xi };
 213   }
 214 }
 215
 216 namespace PR14272 {
 217   auto x { { 0, 0 } }; // expected-error {{cannot deduce type for variable 'x' with type 'auto' from nested initializer list}}
 218 }
 219
 220 namespace initlist_of_array {
 221   void f(std::initializer_list<int[2]>) {}
 222   void f(std::initializer_list<int[2][2]>) = delete;
 223   void h() {
 224     f({{1,2},{3,4}});
 225   }
 226 }
 227
 228 namespace init_list_deduction_failure {
 229   void f();
 230   void f(int);
 231   // FIXME: It'd be nice to track that 'T' became a non-deduced context due to
 232   // overload resolution failure for 'f'.
 233   template<typename T> void g(std::initializer_list<T>);
 234   // expected-note@-1 {{candidate template ignored: couldn't infer template argument 'T'}}
 235   void h() {
 236     g({f}); // expected-error {{no matching function for call to 'g'}}
 237     g({f, h}); // ok
 238   }
 239 }
 240
 241 namespace deleted_copy {
 242   struct X {
 243     X(int i) {}
 244     X(const X& x) = delete; // expected-note {{here}}
 245     void operator=(const X& x) = delete;
 246   };
 247
 248   std::initializer_list<X> x{1}; // expected-error {{invokes deleted constructor}}
 249 }
 250
 251 namespace RefVersusInitList {
 252   struct S {};
 253   void f(const S &) = delete;
 254   void f(std::initializer_list<S>);
 255   void g(S s) { f({S()}); }
 256 }
 257
 258 namespace PR18013 {
 259   int f();
 260   std::initializer_list<long (*)()> x = {f}; // expected-error {{cannot initialize an array element of type 'long (*const)()' with an lvalue of type 'int ()': different return type ('long' vs 'int')}}
 261 }
 262
 263 namespace DR1070 {
 264   struct S {
 265     S(std::initializer_list<int>);
 266   };
 267   S s[3] = { {1, 2, 3}, {4, 5} }; // ok
 268   S *p = new S[3] { {1, 2, 3}, {4, 5} }; // ok
 269 }
 270
 271 namespace ListInitInstantiate {
 272   struct A {
 273     A(std::initializer_list<A>);
 274     A(std::initializer_list<int>);
 275   };
 276   struct B : A {
 277     B(int);
 278   };
 279   template<typename T> struct X {
 280     X();
 281     A a;
 282   };
 283   template<typename T> X<T>::X() : a{B{0}, B{1}} {}
 284
 285   X<int> x;
 286
 287   int f(const A&);
 288   template<typename T> void g() { int k = f({0}); }
 289   template void g<int>();
 290 }
 291
 292 namespace TemporaryInitListSourceRange_PR22367 {
 293   struct A {
 294     constexpr A() {}
 295     A(std::initializer_list<int>); // expected-note {{here}}
 296   };
 297   constexpr int f(A) { return 0; }
 298   constexpr int k = f( // expected-error {{must be initialized by a constant expression}}
 299       // The point of this test is to check that the caret points to
 300       // 'std::initializer_list', not to '{0}'.
 301       std::initializer_list // expected-note {{constructor}}
 302       <int>
 303       {0}
 304       );
 305 }
 306
 307 namespace ParameterPackNestedInitializerLists_PR23904c3 {
 308   template <typename ...T>
 309   void f(std::initializer_list<std::initializer_list<T>> ...tt); // expected-note 2{{conflicting}} expected-note {{incomplete pack}}
 310
 311   void foo() {
 312     f({{0}}, {{'\0'}}); // ok, T = <int, char>
 313     f({{0}, {'\0'}}); // expected-error {{no match}}
 314     f({{0, '\0'}}); // expected-error {{no match}}
 315
 316     f({{0}}, {{{}}}); // expected-error {{no match}}
 317     f({{0}}, {{{}, '\0'}}); // ok, T = <int, char>
 318     f({{0}, {{}}}); // ok, T = <int>
 319     f({{0, {}}}); // ok, T = <int>
 320   }
 321 }
 322
 323 namespace update_rbrace_loc_crash {
 324   // We used to crash-on-invalid on this example when updating the right brace
 325   // location.
 326   template <typename T, T>
 327   struct A {};
 328   template <typename T, typename F, int... I>
 329   std::initializer_list<T> ExplodeImpl(F p1, A<int, I...>) {
 330     // expected-error@+1 {{reference to incomplete type 'const update_rbrace_loc_crash::Incomplete' could not bind to an rvalue of type 'void'}}
 331     return {p1(I)...};
 332   }
 333   template <typename T, int N, typename F>
 334   void Explode(F p1) {
 335     // expected-note@+1 {{in instantiation of function template specialization}}
 336     ExplodeImpl<T>(p1, A<int, N>());
 337   }
 338   class Incomplete;
 339   struct ContainsIncomplete {
 340     const Incomplete &obstacle;
 341   };
 342   void f() {
 343     // expected-note@+1 {{in instantiation of function template specialization}}
 344     Explode<ContainsIncomplete, 4>([](int) {});
 345   }
 346 }
 347
 348 namespace no_conversion_after_auto_list_deduction {
 349   // We used to deduce 'auto' == 'std::initializer_list<X>' here, and then
 350   // incorrectly accept the declaration of 'x'.
 351   struct X { using T = std::initializer_list<X> X::*; operator T(); };
 352   auto X::*x = { X() }; // expected-error {{from initializer list}}
 353
 354   struct Y { using T = std::initializer_list<Y>(*)(); operator T(); };
 355   auto (*y)() = { Y() }; // expected-error {{from initializer list}}
 356 }
 357
 358 namespace designated_init {
 359   constexpr auto a = {.a = 1, .b = 2}; // expected-error {{cannot deduce}}
 360   constexpr auto b = {[0] = 1, [4] = 2}; // expected-error {{cannot deduce}} expected-warning {{C99}}
 361   constexpr auto c = {1, [4] = 2}; // expected-error {{cannot deduce}} expected-warning 2{{C99}} expected-note {{here}}
 362   constexpr auto d = {1, [0] = 2}; // expected-error {{cannot deduce}} expected-warning 2{{C99}} expected-note {{here}}
 363
 364   // If we ever start accepting the above, these assertions should pass.
 365   static_assert(c.size() == 5, "");
 366   static_assert(d.size() == 1, "");
 367 }
 368
 369 namespace weird_initlist {
 370   struct weird {};
 371 }
 372 template<> struct std::initializer_list<weird_initlist::weird> { int a, b, c; };
 373 namespace weird_initlist {
 374   // We don't check the struct layout in Sema.
 375   auto x = {weird{}, weird{}, weird{}, weird{}, weird{}};
 376   // ... but we do in constant evaluation.
 377   constexpr auto y = {weird{}, weird{}, weird{}, weird{}, weird{}}; // expected-error {{constant}} expected-note {{type 'const std::initializer_list<weird_initlist::weird>' has unexpected layout}}
 378 }
 379
 380 auto v = std::initializer_list<int>{1,2,3}; // expected-warning {{array backing local initializer list 'v' will be destroyed at the end of the full-expression}}
 381
 382 std::initializer_list<int> get(int cond) {
 383   if (cond == 0)
 384     return {};
 385   if (cond == 1)
 386     return {1, 2, 3}; // expected-warning {{returning address of local temporary object}}
 387   return std::initializer_list<int>{1, 2, 3}; // expected-warning {{returning address of local temporary object}}
 388 }