llvm-project/clang/test/SemaCXX/derived-to-base-ambig.cpp

// RUN: %clang_cc1 -fsyntax-only -verify %s
class A { };
class B : public A { };
class C : public A { };
class D : public B, public C { };

void f(D* d) {
  A* a;
  a = d; // expected-error{{ambiguous conversion from derived class 'D' to base class 'A':}} expected-error{{incompatible type assigning 'D *', expected 'A *'}}
}

class Object2 { };
class A2 : public Object2 { };
class B2 : public virtual A2 { };
class C2 : virtual public A2 { };
class D2 : public B2, public C2 { };
class E2 : public D2, public C2, public virtual A2 { };
class F2 : public E2, public A2 { };

void g(E2* e2, F2* f2) {
  Object2* o2;
  o2 = e2;
  o2 = f2; // expected-error{{ambiguous conversion from derived class 'F2' to base class 'Object2':}} expected-error{{incompatible type assigning 'F2 *', expected 'Object2 *'}}
}

// Test that ambiguous/inaccessibility checking does not trigger too
// early, because it should not apply during overload resolution.
void overload_okay(Object2*);
void overload_okay(E2*);

void overload_call(F2* f2) {
  overload_okay(f2);
}