Re:C23 is finished: Here is what is on the menu
by Someone on Friday August 05, 2022 @02:04PM
(#32359669)
I think this would work: first, determine the range. For unsigned variants, we have whatever_max = (whatever)(-1), if it isn’t already defined.
That makes parsing the unsigned variant relatively simple. Undefined behavior would be end-of-game, but unsigned addition and multiplication will not invoke that (if you need he,p, look at your favorite multiple-precision library for ideas about detecting wraparound)
For parsing signed integers, derive the min and max values of the signed variant from the max value of the unsigned one ((whatever_max - 1) / 2 or something like that
Then parse your input to the unsigned variant first, then check whether it fits in the unsigned version.
That makes parsing the unsigned variant relatively simple. Undefined behavior would be end-of-game, but unsigned addition and multiplication will not invoke that (if you need he,p, look at your favorite multiple-precision library for ideas about detecting wraparound)
For parsing signed integers, derive the min and max values of the signed variant from the max value of the unsigned one ((whatever_max - 1) / 2 or something like that
Then parse your input to the unsigned variant first, then check whether it fits in the unsigned version.