'operator <<' is ambiguous

Trying a little exercise on overloading the <<. MSVC++ 6.0 will not compile because it says the << operator is ambiguous. It's not ambiguous to me, I know exactly what it's doing. But my compiler doesn't like it. Can anyone help ??

Here is the prototype:

Code:

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friend ostream& operator<<(ostream&, const IntegerSet&);

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Here is the function definition:

Code:

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ostream& operator<<(ostream& output, const IntegerSet& Set)
{
        output << "\n{ ";
        for (int j = 0; j < Set.range; j++)  //range is a public variable of class IntegerSet
            if (Set.array[j] == 1)
              output << j << '\t';          //array is a public variable of class Integerset
        output << "}" << endl;
        return output;
}

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Here is an example use of the overloaded operator:

Code:

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cout << "set A = " << setA << endl;

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ambiguous calls have nothing to do with the defination of the function and everything to do with the prototypes.

What is IntegerSet? What our functions are defined? Did the error say with what other functions is ambiguous with? (gcc does)

VC++ 6 has issues with friend classes where perfectly legitimate code will fail to compile. I recommend getting another compiler, because it's just not worth the effort to work around all of the problems with that one.

I was able to resolve this by explicitly defining what parts of the std namespace I wanted to use. I'm guessing you've got a using namespace std; in there somewhere. If you change that to something like the following, it should compile.

Code:

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using std::ostream;
using std::endl;
using std::cout;

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However, Prelude's completely right. Get a different compiler.

how many << operators have you defined. what are they?

can you paste the compiler error returned by compiler out here

tried it in another compiler.. and it works fine..!!@#!!! :rolleyes:

>!!@#!!!
I feel your pain. I had to write code that would compile under multiple compilers, including VC++ 6, for some time. Thankfully, I don't have that particular restriction anymore. I can actually use C++ as it was meant to be used.