One of the most annoying problems in C and C++ (and Objective-C&#x2F;C++). Most of the time we deal with quantities, sizes, distances, coordinates, identifiers. Except for the latter, all others can end up in the negative space even when we think they shouldn&#x27;t. Having said that, identifiers and enumerated codes should also live in the signed realm as they can get converted to other types, again, in ways we can&#x27;t always predict (and result in bugs).