Comment by Arnavion

Neat similarity to Zig's approach to generic types. The generic type is defined as a type constructor, a function that returns a type. Every instantiation of that generic type is an invocation of that function. So the generic growable list type is `fn ArrayList(comptype T: type) type` and a function that takes two lists of i32 and returns a third is `fn foo(a: ArrayList(i32), b: ArrayList(i32)) ArrayList(i32)`