[steveklabnik]

You would be surprised, at least with array access stuff. And, if it doesn't, you can often help it understand with a bit of work. Sometimes an assert before a loop or re-slicing something can take a check in the body of a loop and move it out to a single one.

I ported a small C function to Rust recently that involved some looping, and all of the bounds checking was completely eliminated, even once I took the line-by-line port and turned it into a slightly higher level one with slices and iterators instead of pointer + length.