Ambiguous reference to template class (C++)

Question

I am new to template classes, and tried to implement a very simple program, just to try out the functionality and syntax. I initialise a template class distance, and then try to get the data and display it.

#include<iostream>
using namespace std;

template <class T>

class distance {

T feet;
T inches;

public:
    distance ()
    {

    }
T getdata (T f, T i)
{
    feet=f;
    inches=i;
}
void showdata ()
{
    cout<<"Distance is "<<feet<<" feet and "<<inches<<" inches";
}

};

int main ()

{

    distance <int> x;
    x.getdata(5,7);
    x.showdata();


}

However, on the distance <int> x line, I get the error stating 'error: reference to 'distance' is ambiguous'. I am not able to figure out my error.

Unable to reproduce your compilation error. This is obviously not the code that produces the compilation error. Your shown code fails to meet all requirements for a [mre], therefore nobody will be able to help you; at most you can expect are random guesses as to what the problem might be. Although I think I have a pretty good guess as to the common error that has this result, I cannot be sure, due your failure to provide a [mre], to confirm it. — Sam Varshavchik, Feb 13 '20 at 03:47
I have edited it to include the header files and library that I used. Is that what you were referring to? — Pranav Krishnan, Feb 13 '20 at 03:52

score 2 · Accepted Answer · answered Feb 13 '20 at 03:56

using namespace std;

You've just discovered why using namespace std; is bad practice.

This injects the C++ library's std::distance template into your program's global namespace, causing a name conflict with your own distance template.

Removing this, replacing all couts with std::couts, and fixing the return value from getdata() fixed all compilation errors.

Use this as a learning lesson: avoid using namespace std; in the future, or be prepared to deal with mysterious compilation errors.

Ambiguous reference to template class (C++)

1 Answers1