C++ ofstream Binary Mode - Written file still looks like plain text

Question

I have an assignment that wants plain text data to be read in from a file, and then outputted to a separate binary file. With that being said, I expect to see that the contents of the binary file not to be intelligible for human reading. However, when I open the binary file the contents are still appearing as plain text. I am setting the mode like this _file.open(OUTFILE, std::ios::binary). I can't seem to figure out what I'm missing. I've followed other examples with different methods of implementation, but there's obviously something I'm missing.

For the purpose of posting, I created a slimmed down test case to demonstrate what I'm attempting.

Thanks in advance, help is greatly appreciated!

Input File: test.txt

Hello World

main.cpp

#include <iostream>
#include <fstream>

using namespace std;

#define INFILE "test.txt"
#define OUTFILE "binary-output.dat"


int main(int argc, char* argv[]) {

    char* text = nullptr;
    int nbytes = 0;
    // open text file
    fstream input(INFILE, std::ios::in);
    if (!input) {
        throw "\n***Failed to open file " + string(INFILE) + " ***\n";
    }

    // copy from file into memory
    input.seekg(0, std::ios::end);
    nbytes = (int)input.tellg() + 1;

    text = new char[nbytes];

    input.seekg(ios::beg);
    int i = 0;
    input >> noskipws;
    while (input.good()) {
        input >> text[i++];
    }
    text[nbytes - 1] = '\0';
    cout << "\n" << nbytes - 1 << " bytes copied from file " << INFILE << " into memory (null byte added)\n";

    if (!text) {
        throw "\n***No data stored***\n";
    } else {
        // open binary file for writing
        ofstream _file;
        _file.open(OUTFILE, std::ios::binary);

        if (!_file.is_open()) {
            throw "\n***Failed to open file***\n";
        } else {
            // write data into the binary file and close the file
            for (size_t i = 0U; i <= strlen(text); ++i) {
                _file << text[i];
            }

            _file.close();
        }
    }
}

Answer 1

As stated here, std::ios::binary isn't actually going to write binary for you. Basically, it's the same as std::ios::out except things like \n aren't converted to line breaks.

You can convert text to binary by using <bitset>, like this:

#include <iostream>
#include <vector>
#include <bitset>

int main() {
    std::string str = "String in plain text";
    std::vector<std::bitset<8>> binary; // A vector of binaries

    for (unsigned long i = 0; i < str.length(); ++i) {
        std::bitset<8> bs4(str[i]);
        binary.push_back(bs4);
    }

    return 0;
}

And then write to your file.