[jasonwatkinspdx]

On modern processors simple arithmetic like incrementing is effectively free. Control dependence is expensive. Data dependence is somewhere between. Fat pointers do not add any dependence. Storing the end has little cost given shadow registers.

If this had been adopted 20 years ago the likely outcome would be that cpus might have fractionally more integer resources. It wouldn't affect the wallclock speed of any code.

All of the operations you describe are done just as easily with fat pointers with the additional advantage of being applicable to truly arbitrary data, not just null clean strings.