Simple cyclic queue (implementation of C ++ template Technology)

The following code is only used by me to review the data structure. The practicality of N is low ~~ Haha:>

/// Example of a simple cyclic queue implemented by C ++ template technology. /// # include <cstdlib> # include <iostream> # include <iomanip> # include <stdexcept> // cyclic queue template. //// because the end of the cyclic queue is always empty, the physical space of the queue should be 1 larger than the Logical space of the specified queue. // The returned queue size should be logical. //// when you enter or exit the queue, an exception is thrown when the top or bottom overflow occurs. // template <typename T> class circularqueue {PRIVATE: T * _ pqueue; size_t _ front, _ rear, _ size; static const size_t _ max_queue_size = 20; public: circularqueue (const size_t size = _ max_queue_size ):_ Front (0), _ rear (0), _ SIZE (size + 1) {_ pqueue = new T [_ SIZE];} ~ Circularqueue (void) {Delete [] _ pqueue;} size_t getsize (void) const {return _ size-1;} t getfront (void) const {If (isempty ()) {Throw STD: underflow_error ("the queue is empty! ");} Return _ pqueue [_ front];} bool isempty (void) const {return _ front ==_ rear;} bool isfull (void) const {return (_ rear + 1) % _ size = _ front;} void enqueue (const T & Val) {If (isfull () {Throw STD :: overflow_error ("the team is full! ");} _ Pqueue [_ rear] = val; _ rear = (_ rear + 1) % _ size;} t dequeue (void) {If (isempty ()) {Throw STD: underflow_error ("the team is empty! ");} T value = _ pqueue [_ front]; _ front = (_ front + 1) % _ size; Return Value ;}}; /// queue test // int main (void) {circularqueue <int> queue; const size_t queue_size = queue. getsize (); For (size_t I = 0; I <queue_size; ++ I) {queue. enqueue (I);} // queue. enqueue (queue_size); STD: cout <STD: Endl <"queue" <(queue. isfull ()? "": "No") <"full." <STD: Endl <"queue" <(queue. isempty ()? "": "No") <"is empty. "<STD: Endl; For (size_t I = 0; I <queue_size; ++ I) {STD: cout <STD: SETW (3) <queue. dequeue ();} // STD: cout <STD: SETW (3) <queue. dequeue (); STD: cout <STD: Endl <"queue" <(queue. isfull ()? "": "No") <"full." <STD: Endl <"queue" <(queue. isempty ()? "": "No") <"blank." <STD: Endl; return exit_success ;}