c++ file io & splitting by separator

Question

I have a file with data listed as follows:

0,       2,    10
10,       8,    10
10,       10,   10
10,       16,   10
15,       10,   16
17,       10,   16

I want to be able to input the file and split it into three arrays, in the process trimming all excess spaces and converting each element to integers.

For some reason I can't find an easy way to do this in c++. The only success I've had is by inputting each line into an array, and then regexing out all the spaces and then splitting it up. This entire process took me a good 20-30 lines of code and its a pain to modify for say another separator(eg. space), etc.

This is the python equivalent of what I would like to have in C++:

f = open('input_hard.dat')
lines =  f.readlines()
f.close()

#declarations
inint, inbase, outbase = [], [], []

#input parsing
for line in lines:
    bits = string.split(line, ',')
    inint.append(int(bits[0].strip()))
    inbase.append(int(bits[1].strip()))
    outbase.append(int(bits[2].strip()))

The ease of use of doing this in python is one of the reasons why I moved to it in the first place. However, I require to do this in C++ now and I would hate to have to use my ugly 20-30 line code.

Any help would be appreciated, thanks!

Answer 1

There's no real need to use boost in this example as streams will do the trick nicely:

int main(int argc, char* argv[])
{
    ifstream file(argv[1]);

    const unsigned maxIgnore = 10;
    const int delim = ',';
    int x,y,z;

    vector<int> vecx, vecy, vecz;

    while (file)
    {
        file >> x;
        file.ignore(maxIgnore, delim);
        file >> y;
        file.ignore(maxIgnore, delim);
        file >> z;

        vecx.push_back(x);
        vecy.push_back(y);
        vecz.push_back(z);
    }
}

Though if I were going to use boost I'd prefer the simplicity of tokenizer to regex... :)