You remember Fortran's old issue about float's vs. ints and variable names? Seriously, if you have languages with signed & unsigned types, and implicit convers

You remember Fortran's old issue about float's vs. ints and variable names? Seriously, if you have languages with signed & unsigned types, and implicit conversion between the two, this can happen. In languages that don't have these features, it can't. However, almost all of them ALSO have ways that poorly written code works until it doesn't. It's a phenomenon very reminiscent of the halting problem.