Custom type passed to function as a parameter

Question

When I define a custom type, it seems that the type of the underlying type makes a difference about whether I can pass it to a function as is or I need to convert it.

Answer 1

Go has a strict type system. Just because your type is merely an alias for int doesn't mean you can interchange the two freely, you'll still have to do a type conversion. Below is a working version of your main, here's the code on play ground: https://play.golang.org/p/BDTXnnG9Lg