queueArrayCircular

#include <iostream>

template <class T, int size>
class Queue
{
    T queue[size]{};
    int begin;
    int end;
    int count;
public:
    Queue(): begin{0}, end{0}, count{0} {};
    bool empty() {return count == 0;};
    bool full() {return count == size;};
    bool enqueue(const T& el);
    bool dequeue(T& el);
    int length() {return count;};
    void show();
};

template <class T, int size>
bool Queue<T,size>::enqueue(const T& el)
{
    if (count < size)
    {
        queue[end] = el;
        ++end %= size;
        ++count;
        return true;
    }
    return false;
}
template <class T, int size>
bool Queue<T,size>::dequeue(T& el)
{
    if (count>0)
    {
        el = queue[begin];
        queue[begin]=0; //HACK!
        ++begin %= size;
        --count;
        return true;
    }
    return false;
}

template <class T, int size>
void Queue<T,size>::show()
{
    for (const T& el: queue)
    {
        std::cout << el << ' ';
    }
    std::cout << '\n';
}

int main()
{
    Queue<int,10> q;
    q.show();
    std::cout << q.empty() << '\n';
    std::cout << q.full() << '\n';

    for (int i{1}; i<9; ++i)
    {
        q.enqueue(i);
        q.show();
    }

    for (int i{1}; i<5; ++i)
    {
        int el{0};
        q.dequeue(el);
        std::cout << "El: " << el << '\n';
        q.show();
    }

    for (int i{1}; i<9; ++i)
    {
        if ( q.enqueue(i) )
        {
            q.show();
        }
        else
        {
            std::cout << "FULL!\n";
        }
    }

    for (int i{1}; i<20; ++i)
    {
        int el{0};
        if (q.dequeue(el))
        {
            std::cout << "El: " << el << '\n';
            q.show();
        }
        else
        {
            std::cout << "EMPTY!\n";
        }
    }

    for (int i{1}; i<20; ++i)
    {
        if ( q.enqueue(i) )
        {
            q.show();
        }
        else
        {
            std::cout << "FULL!\n";
        }
    }

    for (int i{1}; i<20; ++i)
    {
        int el{0};
        if (q.dequeue(el))
        {
            std::cout << "El: " << el << '\n';
            q.show();
        }
        else
        {
            std::cout << "EMPTY!\n";
        }
    }

}