clang/test/CXX/drs/cwg11xx.cpp

   1 // RUN: %clang_cc1 -std=c++98 %s -verify=expected,cxx98 -fexceptions -fcxx-exceptions -pedantic-errors
   2 // RUN: %clang_cc1 -std=c++11 %s -verify=expected -fexceptions -fcxx-exceptions -pedantic-errors
   3 // RUN: %clang_cc1 -std=c++14 %s -verify=expected -fexceptions -fcxx-exceptions -pedantic-errors
   4 // RUN: %clang_cc1 -std=c++17 %s -verify=expected -fexceptions -fcxx-exceptions -pedantic-errors
   5 // RUN: %clang_cc1 -std=c++2a %s -verify=expected -fexceptions -fcxx-exceptions -pedantic-errors
   6
   7 namespace cwg1110 { // cwg1110: 3.1
   8 #if __cplusplus >= 201103L
   9 template <typename T>
  10 T return_T();
  11
  12 struct A;
  13
  14 template <typename>
  15 struct B;
  16
  17 decltype(return_T<A>())* a;
  18 decltype(return_T<B<int>>())* b;
  19 #endif
  20 } // namespace cwg1110
  21
  22 namespace cwg1111 { // cwg1111: 3.2
  23 namespace example1 {
  24 template <typename> struct set; // #cwg1111-struct-set
  25
  26 struct X {
  27   template <typename T> void set(const T &value); // #cwg1111-func-set
  28 };
  29 void foo() {
  30   X x;
  31   // FIXME: should we backport C++11 behavior?
  32   x.set<double>(3.2);
  33   // cxx98-error@-1 {{lookup of 'set' in member access expression is ambiguous; using member of 'X'}}
  34   //   cxx98-note@#cwg1111-func-set {{lookup in the object type 'X' refers here}}
  35   //   cxx98-note@#cwg1111-struct-set {{lookup from the current scope refers here}}
  36 }
  37
  38 struct Y {};
  39 void bar() {
  40   Y y;
  41   y.set<double>(3.2);
  42   // expected-error@-1 {{no member named 'set' in 'cwg1111::example1::Y'}}
  43 }
  44 } // namespace example1
  45
  46 namespace example2 {
  47 struct A {};
  48 namespace N {
  49 struct A {
  50   void g() {}
  51   template <class T> operator T();
  52 };
  53 } // namespace N
  54
  55 void baz() {
  56   N::A a;
  57   a.operator A();
  58 }
  59 } // namespace example2
  60 } // namespace cwg1111
  61
  62 namespace cwg1113 { // cwg1113: partial
  63   namespace named {
  64     extern int a; // #cwg1113-a
  65     static int a;
  66     // expected-error@-1 {{static declaration of 'a' follows non-static}}
  67     //   expected-note@#cwg1113-a {{previous declaration is here}}
  68   }
  69   namespace {
  70     extern int a;
  71     static int a; // ok, both declarations have internal linkage
  72     int b = a;
  73   }
  74
  75   // FIXME: Per CWG1113 and CWG4, this is ill-formed due to ambiguity: the second
  76   // 'f' has internal linkage, and so does not have C language linkage, so is
  77   // not a redeclaration of the first 'f'.
  78   //
  79   // To avoid a breaking change here, Clang ignores the "internal linkage" effect
  80   // of anonymous namespaces on declarations declared within an 'extern "C"'
  81   // linkage-specification.
  82   extern "C" void f();
  83   namespace {
  84     extern "C" void f();
  85   }
  86   void g() { f(); }
  87 }
  88
  89 // cwg1150: na