A FIFO Stack implementation using a simple array.

QeueArray.cpp

#include <iostream>
#include <exception>
#include <stdexcept>
#include <functional>
#include <string>

// 1234--------

template<typename T>
class QeueArray
{
public:
    QeueArray()
    {
        allocated_ = 1;
        N_ = 0;
        data_ = new T[allocated_];
    }

    void push_back(T item)
    {
        if (N_ == allocated_)
        {
            T* copy = data_;
            allocated_ *= 2;
            data_ = new T[allocated_];
            for (int i = 0; i < N_; ++i)
                data_[i] = copy[i];
        }

        data_[N_++] = item;
    }

    T pop_back()
    {
        if (N_ == 0) throw std::out_of_range("The queue is actually empty.");
        if (N_ == allocated_ / 4)
        {
            T* copy = data_;
            allocated_ /= 2;
            data_ = new T[allocated_];
            for (int i = 0; i < N_; ++i)
                data_[i] = copy[i];
        }

        return data_[--N_];
    }

    size_t size()
    {
        return N_;
    }

    T operator[] (int i)
    {
        return data_[i];
    }

private:
    T* data_;
    size_t allocated_;
    size_t N_;

};

int main(int argc, char const *argv[])
{
    QeueArray<int> q;

    for (int i = 0; i < 200000000; i++)
        q.push_back(2);

    return 0;
}