A return statement without arguments is called a naked return. It returns the named return values automatically:
func split(sum int) (x, y int) {
x = sum * 4 / 9
y = sum - x
return // returns x and y
}
Naked returns work only with named return values. They can make short functions cleaner but hurt readability in longer functions. Use them sparingly and only when the function body is short enough to see all assignments at once.