cppStaticStackClass

#include <iostream>

template <typename ElemT, size_t size>
class Stack
{
    ElemT storage[size];
    int topPosition;
    static const int emptyStack{ -1 };
public:
    Stack() : topPosition{ emptyStack } {}
    size_t getSize()const { return size; }
    bool empty()const { return topPosition == emptyStack; }
    bool full()const { return topPosition == size - 1; }
    ElemT& top() { return storage[topPosition]; }
    const ElemT& top()const { return storage[topPosition]; }
    bool push(const ElemT& elem)
    {
        if (!full())
        {
            storage[++topPosition] = elem;
            return true;
        }
        return false;
    }

    bool pop()
    {
        if (!empty())
        {
            --topPosition;
            return true;
        }
        return false;
    }

    template <typename ElemT, size_t size>
    friend std::ostream& operator<<(std::ostream& out, const Stack<ElemT, size>& stack);
};


template <typename ElemT, size_t size>
std::ostream& operator<<(std::ostream& out, const Stack<ElemT, size>& stack)
{
    if (!stack.empty())
    {
        out << stack.top() << '\n';
    }
    else
    {
        out << "[empty]\n";
    }
    return out;
}

int main()
{
    Stack<int, 5> stack;

    std::cout << "Pushing in...\n";
    for (int cnt{ 0 }; !stack.full(); stack.push(cnt++))
    {
        std::cout << cnt << '\n';
    }
    stack.push(100);
    std::cout << stack << '\n';

    std::cout << "Poping out...\n";
    for (;!stack.empty(); stack.pop())
    {
        std::cout << stack;
    }
    stack.pop();
    std::cout << stack;

}