Customize the class template to implement queue

# Include "stdafx. H "<br/> # include <iostream> <br/> using namespace STD; <br/> // incorrect example <br/> // template <class T> class listitem; <br/> // template <class T> class list {<br/> // public: <br/> // list <t> (); <br/> // list <t> (const list <t> &); <br/> // list <t> & operator = (const list <t> &); <br/> //~ List (); <br/> // void insert (listitem * PTR, T value _); <br/> // listitem * Find (T value _); <br/> // <br/>/PRIVATE: <br/> // listitem * front; <br/> // listitem * end; <br/> // }; <br/> template <class type> <br/> class queueitem {<br/> public: <br/> queueitem (const type & T): item (t), next (0) {}< br/> type item; <br/> queueitem * next; <br/>}; <br/> template <class type> <br/> class queue {<br/> Public: <br/> Qu EUE (): Head (0), tail (0) {}< br/> Queue (const queue & Q): Head (0), tail (0) {<br/> copy_elems (Q ); <br/>}< br/> template <class type2> // here, the object is declared to support type conversion <br/> queue <type> & operator = (const queue <type2> &); <br/> ~ Queue () {destroy () ;}< br/> type & Front () {return head-> item ;}< br/> const type & Front () const {return head-> item ;}< br/> void push (const type &); <br/> void POP (); <br/> bool empty () const {<br/> return head = 0; <br/>}< br/> PRIVATE: <br/> queueitem <type> * head; <br/> queueitem <type> * tail; <br/> void destroy (); <br/> void copy_elems (const queue &); <br/> }; <br/> template <class type> <br/> void queue <Type >:: push (const type & Val) <br/>{< br/> queueitem <type> * PT = new queueitem <type> (VAL ); <br/> If (empty () <br/> head = tail = pt; <br/> else {<br/> tail-> next = pt; <br/> tail = pt; <br/>}< br/> template <class type> <br/> void queue <type> :: pop () <br/>{< br/> queueitem <type> * P = head; <br/> head = head-> next; <br/> Delete P; <br/>}< br/> template <class type> <br/> void queue <type >:: destroy () <br/> {<Br/> while (! Empty () <br/> POP (); <br/>}< br/> template <class type> <br/> void queue <type> :: copy_elems (const queue & orig) <br/>{< br/> for (queueitem <type> * PT = orig. head; PT; Pt = Pt-> next) <br/> push (Pt-> item ); <br/>}< br/> template <class type> <br/> template <class type2> // The purpose of this statement is to support type conversion. <br/> queue <type> & queue <type>:: Operator = (const queue <type2> & orig) <br/> {<br/> If (void *) This = (void *) & orig) {<br/> * th Is; <br/>}< br/> queue <type2> TMP (orig); <br/> destroy (); // Delete </P> <p> while (! TMP. empty () <br/>{< br/> push (TMP. front (); <br/> TMP. pop (); <br/>}< br/> return * This; <br/>}< br/> int main () <br/>{ <br/> queue <int> qi; <br/> short S = 43; <br/> int I = 23; <br/> Qi. push (s); <br/> Qi. push (I); <br/> queue <float> AI; <br/> AI = qi; <br/> queue <int> Bi; <br/> return 0; <br/>}