> Let's say you have a function in a library that has signature Int32 -> Int32. Then you realize you need to do the same thing, but for Int64. You can't reuse i

> Let's say you have a function in a library that has signature Int32 -> Int32. Then you realize you need to do the same thing, but for Int64. You can't reuse it by wrapping. For that we have typeclasses.