Function points are a programming-language-independent way of describing the size of a piece of software. However, a given programming language has a typical amount of lines-of-code per function point, allowing a rough estimate of function points from LOC and vice versa. Even more importantly, a programmer or team tends to generate a characteristic amount of function points per month.
It's not a panacea but I've had good luck with function point counting over the years; it's definitely a good tool to have in your belt. It just got standardized.