How can I read lines from a text file into a variable

Question

I know that there's many questions here about reading lines from a text file and storing it in a c++ struct. However, those questions all contain text files that have precisely the information they needed, such as a text file with :

Tom 123

Jim 234

However, what if my text file had something like

// The range of 'horizontal' indices, inclusive
// E.g. if the range is 0-4, then the indices are 0, 1, 2, 3, 4
GridX_IdxRange=0-8

// The range of 'vertical' indices, inclusive
// E.g. if the range is 0-3, then the indices are 0, 1, 2, 3   
GridY_IdxRange=0-9

How would I be able to get just the numbers 0-8 and 0-9 besides the equal sign in gridX and gridY to be stored in my struct?

What I tried:

struct config {
    int gridRange[2];
    int gridX;
    int gridY;
    int cityId;
    int cloudCover;
    int pressure;
    std::string cityName;
};

    config openFile(std::string filename, config &con) {
    std::fstream inputFile(filename.c_str(), std::fstream::in);
    if (inputFile.is_open()) {

        std::string line;
        for (int i = 0; i < 2; i++) {
            while (std::getline(inputFile, line)) {
                inputFile >> con.gridRange[i];
                std::cout << con.gridRange[i]; //to show what is stored in the array
                
            }
        }

        //std::cout << range << std::endl;
        std::cout << std::endl;
        return con;
    }
    else {
        std::cout << "Unable to open file" << std::endl;
    }
}

Ignore the other variables in the struct as I still do not need them yet. The output I got was

// The range of 'horizontal' indices, inclusive
0

Answer 1

I managed to solve this by adding in if (line[0] != '/' && !line.empty()) { inside the while loop and creating a new string variable called lineArray[5]. The function now looks like this

    config openFile(std::string filename, config &con) {
    std::fstream inputFile(filename.c_str(), std::fstream::in);
    if (inputFile.is_open()) {
        std::string line;
        std::string lineArray[5];
        int count = 0;
        while (std::getline(inputFile, line)) {
            if (line[0] != '/' && !line.empty()) {
                lineArray[count] = line;
                count++;
                }
            }
        std::cout << "Printing out " << lineArray[0] << std::endl;

        std::cout << std::endl;
        return con;
    }
    else {
        std::cout << "Unable to open file" << std::endl;
    }
}

And the output I'll get is Printing out GridX_IdxRange=0-8.