Как создать класс кот может создать general purpose counting objects

int main( )
{
    cout << "Testing the CounterType class";
 
    CounterType testOne, testTwo(50);
 
    cout << "\n\nInitial Values:\n"  << testOne.getCount() << " ";
    testTwo.outputCount(cout); 
 
    while (testOne.getCount() < 30)
        testOne.plusOne();
 
    while (testTwo.getCount() > 30)
        testTwo.minusOne();
 
    cout << "\n\nFinal Values:\n" << testOne.getCount() << " ";
    testTwo.outputCount(cout); 
 
    return 0;
}

#include <iostream>
#include <stdexcept>
 
class CounterType
{
public:
    explicit CounterType(int count = 1) : count_(count)
    {
        if(count <= 0)
            throw std::invalid_argument("count <= 0");
    }
    void Increment()
    {
        ++count_;
    }
    void Decrement()
    {
        if(count_ > 1)
            --count_;
        else std::cerr << "count_ <= 1" << std::endl;
    }
    int Count() const
    {
        return count_;
    }
    std::ostream& OutputCount(std::ostream& ost)
    {
        return ost << count_;
    }
private:
    int count_;
};
 
int main()
{
    using namespace std;
    CounterType testOne, testTwo(50);
 
    cout << "\n\nInitial Values:\n"  << testOne.Count() << " ";
    testTwo.OutputCount(cout) << std::endl;
 
    while (testOne.Count() < 30)
        testOne.Increment();
 
    while (testTwo.Count() > 30)
        testTwo.Decrement();
 
    cout << "\nFinal Values:\n" << testOne.Count() << " ";
    testTwo.OutputCount(cout) << std::endl;
    
    return 0;
}