template<class Key, class Pred, class A>
bool operator!=(
const set <Key, Pred, A>& lhs,
const set <Key, Pred, A>& rhs);
template<class Key, class Pred, class A>
bool operator!=(
const multiset <Key, Pred, A>& lhs,
const multiset <Key, Pred, A>& rhs);
The template function returns !(lhs == rhs)
.