This is so exciting.

Julia's multiple dispatch is really powerful. In my opinion it's great user experience for implementing generic code.

It has a downside: since you don't know at build-time what types you'll shove inside your functions, you don't know what to compile.

But some times the user does know. What does this, according to my understanding, is that if you tell the compiler what types you'll be using it can compile everything ahead of time.