C++ Dont Create Copies Pass by Reference as it affects performance.

Array.cpp

#include <iostream>
#include "Array.hpp"

Array::Array()
{
    std::cout << "CONSTRUCTOR CALLED" << std::endl;
    for (auto i = 0; i < 100000; i++)
    {
        data.push_back(i*i);
    }
}

Array::Array(const Array& rhs)
{
    std::cout << "COPY CONSTRUCTOR CALLED" << std::endl;
    data.clear();
    for (auto i = 0; i < 100000; i++)
    {
        data.push_back(rhs.data[i]);
    }
}

Array& Array::operator=(const Array& rhs)
{
    std::cout << "COPY Assignment Operator CALLED" << std::endl;
    if (&rhs == this)
    {
        return *this;
    }

    data.clear();
    for (size_t i = 0; i < rhs.data.size(); i++)
    {
        data.push_back(rhs.data[i]);
    }
    return *this;
}

void Array::PrintArray()
{
    for (auto i = 0; i < data.size(); i++)
    {
        std::cout << data[i] << std::endl;
    }
    std::cout << "******************************" << std::endl;       
}

void Array::SetData(int index, int value)
{
    data[index] = value;
}

Array::~Array()
{
    //delete[] data;
}

Array.hpp

#ifndef ARRAY_HPP
#define ARRAY_HPP
#include <vector>

class Array
{
    public:
        Array();

        Array(const Array& rhs);

        // Copy Assignment Operator
        // Object is already constructed we are just making a copy later...
        Array& operator=(const Array& rhs);

        void PrintArray();

        void SetData(int index, int value);

        ~Array();

    private:
        std::vector<int> data;
};

#endif

Caller.cpp

#include "Array.hpp"

void PrintArray(const Array& a)
{
    //a.PrintArray();
}

int main()
{
    // Copy Constructor
    Array myArray;
    myArray.SetData(0,1234567);


    // Copy Assignment Operator
    // Array myArray2;
    // myArray2 = myArray;

    // Copy Constructor is called.
    Array myArray2 = myArray;

    //myArray.PrintArray();
    //myArray2.PrintArray();

    for (size_t i = 0; i < 100; i++)
    {
       PrintArray(myArray);
    }

    return 0;
}