Extend types to code composition

[Xyncgas]

Just like we can build functions with functions, we can build types with types
Often we have structure in codes we write, for every feature it's following these structure
What if we can functionstypespatterns (code) inside types
oh that's an object with every member static
What if I want the signature of these members to be different so I can say type C and type B both have member ToString but one returns integer instead
oh that's a templated programming
I wish there is much more in f#