custom slices

foos.go

package main

import "fmt"

type foo int

type foos []foo

func (f foos) first() foo {
	if len(f) == 0 {
		return 0
	}
	return f[0]
}

func main() {
	f := foos([]foo{1,2,3,4})
	fmt.Print(f.first())
}