Pluggable type sytems

[bmeck]

> In fact, I'd even argue that non-nullability should be the default for 
> pointers and class references

Not against it for class references, but utterly against it for pointers as that is one of main points of using a pointer to me. Using structs, classes, primitive variables, and arrays I would agree the majority of the time do not need null checks as we do not want nulls, however non-nullability of such things can lead to confusion as default values of these (especially classes) does not always have a well defined expectation. We could add something to the compiler to check if it is initialized but what if we do get a null reference for some reason (calling convention to heterogeneous code). If i want a reference to a class and get a pointer from a library as such i would end up getting the pointer and checking for null before making it non-nullable by a cast both of which also take time.