Struct polymorphism?

[mysyljr]

It's having possibilities,I mean polymorphism for struct,and
without a enum declaring thus it can be more scalable if you
should use virtual call in a delegate class,cause it's just what
virtual call is designed for.Since you record the Type all the
time,you get rid of virtual call but lose scalability.I'm
interesting in struct polymorphism because I can choose no
virtual call when no runtime polymorphism is needed but not when
I need