On 7/4/19, Dr. Jürgen Sauermann <mail@jürgen-sauermann.de> wrote: > Regarding signed vs. unsigned, the question is not so much if the chosen > type can hold the value but the number of comparisons needed to compute > if a value fits into a range (where the vast majority of cases the range > starts at 0). > > A signed X falls into range [0, N] iff: X ≥ 0 and X < N > An unsigned X falls into range [0, N] iff: X < N
Understood. It should not be too hard to fix, just make sure that your desired types do not conflict with system types like rlim_t, then either use a compatible type or employ a typecast as a last resort (typecasts are evil and should be avoided). > This fired back badly (with milllions of warnings) when I replaced > Simple_string<X> with std::string<X> which uses unsigned for the length. Been these, done that. :-) Usually, the safest approach when handling sizes is to use size_t type (which is unsigned, just as you prefer) and only reluctantly fallback to ssize_t if you need/must to handle negative sizes for some reason in the same variable (e.g. for error handling). Reluctantly because it is generally a bad idea to convey errors by abusing the data type itself. Unfortunately, in many traditional languages there is no support for algebraic data types to handle these situations in a correct, type-safe way. ./danfe
