Implementing Map, Reduce, and Filter with Go Generics

"While we could usually write the specific code we needed for a particular program, before Go generics it wasn’t easy to write functions on arbitrary container types, such as slices.

For example, we couldn’t write a function that takes a slice of arbitrary type and determines whether the slice contains a given element. Instead, we had to write a function that takes some specific type, such as []int, or []string.

But this is dull, because the logic is exactly the same, whatever the type of the slice element. And now we can write that function just once, for all types. Let’s try."