how to creat circular qeue in c++

#include<iostream>
using namespace std;
#define size 5
int CQ[size], front = -1, rear = -1, iteam;
void insertion();
void deletion();
void display();
void main()
{
while (1){
int ch;
cout << "Enter your choice " << endl;
cout << "1)Insertion " << endl;
cout << "2)Deletion " << endl;
cout << "3)Dispaly" << endl;
cout << "4)Exit" << endl;
cin >> ch;
switch (ch)
{
case 1:
system("cls");
insertion();
break;
case 2:
system("cls");
deletion();
break;
case 3:
system("cls");
display();
break;
case 4:
system("cls");
exit(0);
break;
default:
cout << "invalid input" << endl;

}
}
system("pause");
}

void insertion()
{

if (front == -1)
{
front = 0;
}
rear = (rear + 1) % size;
cout << "Enter value" << endl;
cin >> iteam;
CQ[rear] = iteam;
}
void deletion()
{
if (front == -1 && rear == -1)
{
cout << " Circular Queue is Empty" << endl;
}
else
{
iteam = CQ[size];
front = (front + 1) % size;
}
}
void display()
{
if (front == -1 && rear == -1)
{
cout << " Circular Queue is Empty" << endl;
}
else
{
cout << "Values in Queue" << endl;
for (int i = front; i <= rear; i++)
{
cout << CQ[i] << endl;
}
}
}