xcode6 - Rounding in Swift with round()

Question

While playing around, I found the round() function in swift. It can be used as below:

round(0.8)

Which will return 1, as expected. Here's my question:

how do I round by thousandths in swift?

I want to be able to plug in a number, say 0.6849, and get 0.685 back. How does round() do this? Or, does it not, in which case, what function does?

Answer 1

You can do:

round(1000 * x) / 1000