Initializing "two-dimensional" compile-time enum

[Uranuz]

Thanks! I'll try it. Another question is can I use immutable 
variables in compile time or they are just runtime variables that 
are once initialized and can't be modified? Is it only way to use 
manifest constants (enum). And what is semantics of enum 
constants? In D we have a lot of modifiers: static, enum, const, 
immutable. So sometimes I get stuck with question what to use? 
Could someone briefly explain the purpose of each one of these?