A range only bounded inclusively below (start..).

The RangeFrom start.. contains all values with x >= start.

A RangeFrom can be constructed as a literal as "start.."_r.

Note: Overflow in the Iterator implementation returned by iter() and into_iter() (when the contained data type reaches its numerical limit) is allowed to panic, wrap, or saturate. For integer types like usize integers, this follows the normal rules will panic if usize + 1_usize would otherwise panic in the build configuration. Note also that overflow happens earlier than you might assume: the overflow happens in the call to next that yields the maximum value, as the range must be set to a state to yield the next value.