template< class Key, class Compare, class Alloc >
bool operator==( const set<Key,Compare,Alloc>& lhs,
const set<Key,Compare,Alloc>& rhs ); (1) template< class Key, class Compare, class Alloc >
bool operator!=( const set<Key,Compare,Alloc>& lhs,
const set<Key,Compare,Alloc>& rhs ); (2) template< class Key, class Compare, class Alloc >
bool operator<( const set<Key,Compare,Alloc>&