StructParams

mixin StructParams!("S", int, "x", float, "y"); creates

struct S {
  struct Regular {
    int x;
    float y;
  }
  struct WithDefaults {
    Nullable!int x;
    Nullable!float y;
  }
  struct Func {
    Nullable!(int delegate()) x;
    Nullable!(float delegate()) y;
  }
}

hese structures are intended to be used as arguments of combine function.