SparesMat::operator++() vs SparesMat::operator++(int)

Both SparesMat::operator++() and SparesMat::operator++(int) have the same definition in the docs, namely "moves iterator to the next element". Since it is not defined as SparesMat::operator++(int step) (or some other variable), I am a little confused. Does it increment by the value placed in the parenthesises or is a "don't care"?