Question

I’m writing a program reading a file containing two values in each line. Those values should be stored in two vectors, xVals and yVals. Therefore I use the push_back-function, but I want my code to be more beautiful. Now it’s like:

ifstream file;
file.open("foo.txt");
double TempVal;
while(file >> TempVal){
    xVals.push_back(TempVal);
    file >> TempVal;
    yVals.push_back(TempVal);
}

What I am currently looking for is a solution like this one (just the important line):

while(file >> xVals.push_back(??) >> yVals.push_back(??))

The question marks stand for “I don’t know how to get the value passed by “>>” there…
Is there an EASY (easier than the three lines above) or nicer way to achieve this? 🙂

Thanks

Answer 1

You could do something like this:

double tempX, tempY;
while( file >> tempX >> tempY )
{
    xVals.push_back(tempX);
    yVals.push_back(tempY);
}

If you truly wanted something beautiful, you would define a Point class that performs stream extraction/insertion, and then just use an algorithm:

std::vector<Point> points;
std::copy(
    std::istream_iterator< Point >( file ), std::istream_iterator< Point >()
  , std::back_inserter( points )
);