struct Typedef(TBase)

{

   TBase payload;

   alias payload this;

}

​

alias Xobj = Typedef!(void*);

​

void foo (Xobj obj) {}

​

void main()

{

  void* bad;

  foo(bad);  /* Error: function foo(Typedef!(void*) obj) is not callable using argument types (void*)

               cannot pass argument bad of type void* to parameter Typedef!(void*) obj */

}