Thread: problems with passing ostream variable

Code:

 string str;

                x.read(inFile);
                if (x.animalType()==2 || x.animalType()==3)
                        str = std::cerr;

                x.print(str.c_str()) << endl;

and hte function is...

Code:

ostream& animals::print(ostream& stream = cout) const {

what im trying to do is, read from a file, and if its a dog or a cat, then it'll print out to the error stream.
and if its any other animal then it'll print out to standard output (cout)

any help why this code wont work?

Your variable str is a string, but then you try to assign the cerr stream to it. That won't work. Normally, you might have a variable and assign cout or cerr to it as appropriate. In this case, that variable would have to be a reference to ostream, so it is a little more sloppy because you cannot assign to a reference, only initialize it with something. I would suggest something like this:

Code:

if (x.animalType()==2 || x.animalType()==3)
    x.print(std::cerr) << endl;
else
    x.print(std::cout) << endl;

or this:

Code:

ostream& stream = (x.animalType()==2 || x.animalType()==3) ? std::cerr : std::cout;
x.print(stream) << endl;