I'm, not talking about mixins , they are slithly diferent than what I mean. I don't just want an agregation of fields and methods created from clases.

Also what I'm saying is not like "Multiple Inheriance" at all, the new classes still have a single inheritance path

for my previouse example :

class MyClass<T> : T {

MyClass<Employ> is a subclass o Employ and that's is his type is

typeof (MyClass<Employ>) wich IS an Employ derived type

also MyClass<Company> is a Company type and the only conection to MyClass<Employ> could be the fact that they both are objects

Also i thing the same constraigt system could be applied for "this" reference inside the generic class