Generating Power Set using Bitmap

I was asked to write a function that generate a power set of items. At first I wrote a recursive algorithms but then another approach came to mind. When you calculate how many subsets there are, you can say that each item in the original set can either be or not be in a subset, which means 2^n subsets. This yes/no for including can be seen as a bitmask, and since we know that there are 2^n subsets we can use the number from 0 to 2^n-1 as bitmasks.