text: /*
  TEST_OUTPUT:
  ---
  fail_compilation/fail7173.d(23): Error: expression `b1._a.opBinary(b2._a).fun()` is `void` and has no value
  ---
  */
  struct A{
  
    A opBinary(string op)(A a){ A rt; return rt; }
  
    void fun(){ }
  }
  
  struct B{
  
    A _a;
    alias _a this;
  }
  
  
  void main(){
  
    B b1, b2, b3; b3 = (b1 - b2).fun();
  }
  