#include <iostream>

#include <fstream>

#include <chrono>

#define INPUT_BUFFER_SIZE 1024 * 1024

int main()

{

    using namespace std;

    cout << "Type an input file name: ";

    string filename;

    getline(cin, filename);

    ifstream ifs(filename, ifstream::in | ifstream::binary);

    if (ifs)

    {

        cout << "Type an output file name: ";

        getline(cin, filename);

        ofstream ofs(filename, ofstream::out | ofstream::binary);

        if (ofs)

        {

            cout << "Copying file..." << endl;

            char buffer[INPUT_BUFFER_SIZE];

            chrono::system_clock::time_point startTime = chrono::system_clock::now();

            while (!ifs.eof())

            {

                streamsize numberOfCharacters = ifs.read(buffer, INPUT_BUFFER_SIZE).gcount();

                ofs.write(buffer, numberOfCharacters);

            }

            chrono::system_clock::time_point endTime = chrono::system_clock::now();

            float elapsedTime = static_cast<chrono::duration<float, ratio<, >>>(endTime - startTime).count();

            cout << "File copied, elapsed time: " << elapsedTime << endl;

        }

        else

            cerr << "Cannot open output file: '" << filename << "'!" << endl;

    }

    else

        cerr << "Cannot open input file: '" << filename << "'!" << endl;

    return ;

}

#include <iostream>

#include <fstream>

#define INPUT_BUFFER_SIZE 1024 * 1024

int main()

{

    std::cout << "Enter an input file name: ";

    std::string filename;

    std::getline(std::cin, filename);

    std::ifstream ifs(filename, std::fstream::in);

    if (ifs.is_open())

    {

        std::cout << "Enter an output file name: ";

        std::getline(std::cin, filename);

        std::ofstream ofs(filename, std::fstream::out);

        if (ofs.is_open())

        {

            char buffer[INPUT_BUFFER_SIZE];

            while (!ifs.eof())

            {

                std::streamsize numberOfCharacters = ifs.read(buffer, INPUT_BUFFER_SIZE).gcount();

                std::cout.write(buffer, numberOfCharacters);

                ofs.write(buffer, numberOfCharacters);

            }

        }

        else

            std::cout << "Cannot open file: " << filename << std::endl;

    }

    else

        std::cout << "Cannot open file: " << filename << std::endl;

    return ;

}