用于进行gcc测试

				// { dg-do assemble  }				extern "C" int printf(const char *, ...);								struct VB {				  virtual void f() {				    printf("VB\n");				  }				};								class M : public virtual VB {				public:				  int i;				  void f() {				    printf("M(%d)\n", i);				  }				};								class lM : public M {				};								class rM : public M {				};								class D : public lM, rM { // { dg-error "" } ambiguous function				} d;								int main() {				  ((lM*)&d)->i = 1;				  ((rM*)&d)->i = 2;				  ((rM*)&d)->f();				  ((lM*)&d)->f();				  ((VB*)&d)->f();				}