test/SemaCXX/arrow-operator.cpp

// RUN: %clang_cc1 -fsyntax-only -verify %s
struct T { 
  void f();
};

struct A {
  T* operator->(); // expected-note{{candidate function}}
};

struct B {
  T* operator->(); // expected-note{{candidate function}}
};

struct C : A, B {
};

struct D : A { };

struct E; // expected-note {{forward declaration of 'struct E'}}

void f(C &c, D& d, E& e) {
  c->f(); // expected-error{{use of overloaded operator '->' is ambiguous}}
  d->f();
  e->f(); // expected-error{{incomplete definition of type}}
}