template<class t, class less> struct multiset { typedef set_iterator<t> iterator; multiset(const char* name); multiset(const char* name, const char* directory); multiset(const wchar_t* name); multiset(const wchar_t* name, const wchar_t* directory) ~multiset(); multiset<t>& operator<<(const t& element); t back(); iterator begin() const; long long depth() const; iterator end() const; void erase(); long long erase(const t& key); bool contains(const t& element) const; t front(); list<t> find(const t& key) const; void insert(const t& element); long long length() const; };