Stack in C++

#include <iostream>

        using namespace std;

        #define STACKSIZE 10

        class stack

        {

                private:

                        int arr[STACKSIZE+1];

                        int tos;

                public:

                        stack();

                        void push(int x);

                        int  pop();

                        bool is_empty();

                        bool is_full();

                        int  size();

                        void display();

        };

        stack::stack()

        {

                tos = 0;

        }

        void stack::push(int x)

        {

                if(!is_full())

                        arr[tos++] = x;

                else

                        cout << "Stack is full, Can not push " << x << endl;

        }

        int stack::pop()

        {

                if(!is_empty())

                        return arr[--tos];

                else

                        cout << "Stack is empty, cannot pop" << endl;

                return -1;

        }

        bool stack::is_empty()

        {

                if(tos == 0)

                        return true;

                else

                        return false;

        }

        bool stack::is_full()

        {

                if(tos == STACKSIZE)

                        return true;

                else

                        return false;

        }

        int stack::size()

        {

                return tos;

        }

        void stack::display()

        {

                if(tos == 0)

                {

                        cout << "No elements to display" << endl;

                        return;

                }

                for(int i=0;i

                        cout << arr[i] << " ";

                cout << endl;

        }

        int main()

        {

                stack mystack;

                cout << mystack.size() << endl;

                mystack.push(1);

                if(mystack.is_full())

                        cout << "stack is full" << endl;

                mystack.pop();

                if(mystack.is_empty())

                        cout << "stack is empty" << endl;

        }