Documentation for checked operations says "instead of wrapping around on underflow"

[cuviper]

From @kryptan on July 30, 2015 21:50

Documentation for CheckedAdd, CheckedDiv, CheckedMul, CheckedSub says: Performs operation that returns None instead of wrapping around on underflow.

"instead of wrapping around on underflow" sounds like wrapping on overflow is the default behaviour but it is not.

P.S. there are traits for checked and saturating operations but no trait for wrapped operations, why?

Copied from original issue: rust-num/num#107