test/CXX/temp/temp.decls/temp.mem/p5.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify %s
   2 struct A {
   3   template <class T> operator T*();
   4 };
   5
   6 template <class T> A::operator T*() { return 0; }
   7 template <> A::operator char*(){ return 0; } // specialization
   8 template A::operator void*(); // explicit instantiation
   9
  10 int main() {
  11   A a;
  12   int *ip;
  13   ip = a.operator int*();
  14 }
  15
  16 // PR5742
  17 namespace PR5742 {
  18   template <class T> struct A { };
  19   template <class T> struct B { };
  20
  21   struct S {
  22     template <class T> operator T();
  23   } s;
  24
  25   void f() {
  26     s.operator A<A<int> >();
  27     s.operator A<B<int> >();
  28     s.operator A<B<A<int> > >();
  29   }
  30 }
  31
  32 // PR5762
  33 class Foo {
  34  public:
  35   template <typename T> operator T();
  36
  37   template <typename T>
  38   T As() {
  39     return this->operator T();
  40   }
  41
  42   template <typename T>
  43   T As2() {
  44     return operator T();
  45   }
  46
  47   int AsInt() {
  48     return this->operator int();
  49   }
  50 };
  51
  52 template float Foo::As();
  53 template double Foo::As2();
  54
  55 // Partial ordering with conversion function templates.
  56 struct X0 {
  57   template<typename T> operator T*() {
  58     T x = 1;
  59     x = 17; // expected-error{{read-only variable is not assignable}}
  60   }
  61
  62   template<typename T> operator T*() const; // expected-note{{explicit instantiation refers here}}
  63
  64   template<typename T> operator const T*() const {
  65     T x = T();
  66     return x; // expected-error{{cannot initialize return object of type 'const char *' with an lvalue of type 'char'}}
  67   }
  68 };
  69
  70 template X0::operator const char*() const; // expected-note{{'X0::operator const char *<char>' requested here}}
  71 template X0::operator const int*(); // expected-note{{'X0::operator const int *<const int>' requested here}}
  72 template X0::operator float*() const; // expected-error{{explicit instantiation of undefined function template}}
  73
  74 void test_X0(X0 x0, const X0 &x0c) {
  75   x0.operator const int*();
  76   x0.operator float *();
  77   x0c.operator const char*();
  78 }