clang/test/CXX/drs/dr11xx.cpp

   1 // RUN: %clang_cc1 -std=c++98 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
   2 // RUN: %clang_cc1 -std=c++11 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
   3 // RUN: %clang_cc1 -std=c++14 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
   4 // RUN: %clang_cc1 -std=c++17 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
   5 // RUN: %clang_cc1 -std=c++2a %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
   6
   7 namespace dr1111 { // dr1111: yes
   8 namespace example1 {
   9 template <typename> struct set;
  10
  11 struct X {
  12   template <typename T> void set(const T &value);
  13 };
  14 void foo() {
  15   X x;
  16 #pragma clang diagnostic push
  17 #if __cplusplus < 201103L
  18 #pragma clang diagnostic ignored "-Wambiguous-member-template"
  19 #endif
  20   x.set<double>(3.2);
  21 #pragma clang diagnostic pop
  22 }
  23
  24 struct Y {};
  25 void bar() {
  26   Y y;
  27   y.set<double>(3.2); // expected-error {{no member named 'set' in 'dr1111::example1::Y'}}
  28 }
  29 } // namespace example1
  30
  31 namespace example2 {
  32 struct A {};
  33 namespace N {
  34 struct A {
  35   void g() {}
  36   template <class T> operator T();
  37 };
  38 } // namespace N
  39
  40 void baz() {
  41   N::A a;
  42   a.operator A();
  43 }
  44 } // namespace example2
  45 } // namespace dr1111
  46
  47 namespace dr1113 { // dr1113: partial
  48   namespace named {
  49     extern int a; // expected-note {{previous}}
  50     static int a; // expected-error {{static declaration of 'a' follows non-static}}
  51   }
  52   namespace {
  53     extern int a;
  54     static int a; // ok, both declarations have internal linkage
  55     int b = a;
  56   }
  57
  58   // FIXME: Per DR1113 and DR4, this is ill-formed due to ambiguity: the second
  59   // 'f' has internal linkage, and so does not have C language linkage, so is
  60   // not a redeclaration of the first 'f'.
  61   //
  62   // To avoid a breaking change here, Clang ignores the "internal linkage" effect
  63   // of anonymous namespaces on declarations declared within an 'extern "C"'
  64   // linkage-specification.
  65   extern "C" void f();
  66   namespace {
  67     extern "C" void f();
  68   }
  69   void g() { f(); }
  70 }