Well the int version returns the correct answer for "empty()" unlike unsigned. The size of a list of 2^32-1 elements should not be reported as zero, nor as "emp

Well the int version returns the correct answer for "empty()" unlike unsigned. The size of a list of 2^32-1 elements should not be reported as zero, nor as "empty". In this case, the compiler has to enforce wrap semantics for unsigned, which is an applicaton-level level bug if it occurs, and doesn't need to enforce it for int, which happens to lead to the right answer for empty (i.e., it checks if it has at least one element, which continues to return the correct "not empty" answer for 2^32-1 or 2^31-1 elements). Both get the wrong answer for size() (over different domains), if you allow lists that large: they can't even represent very large lists.