Thread: File IO question

At the suggestion of some cprogramming experts, I started using filestreams rather than the old style FILE* c code.

Now I have some problems that I'm having trouble solving. This code opens a file with two columns of double data of unknown length. I want to

Code:

ifstream f( filename );
double a,p;

vector <double> v;

if(f.is_open())
{
	while(!f.eof())
	{
		f >> a >> p;
		v.push_back( a );
		v.push_back( p );
	}
}
else
	cout << "Unable to open file";

The problem is that if my input file has a return after the last number, eof says there is still more to read, and the while loop keeps going, pushing 1 additional element onto each vector. Is testing for an identical values the only way to prevent this from happening? Does f >> a >> p raise a flag somewhere that says it didn't read a double?

Thanks for the help.

OK, well I seemed to have answered it myself:

Code:

if(f >> a)

This tests for valid input.

Well I guess I'm still wondering if there would be a way to push the value right onto the vector array without saving it in a temp variable. Something like this:

Code:

s.push( f >> double );

Is this possible?