Templates trouble

Hello, everyone! This might seem an easy question to you, and I wouldn't even post it if it wasn't for my love of clean code. So here goes:

What I want to do is read some pairs of values from a file, one on a line; for example, I might have a file that looks like this:

Code:

---

john
7
paul
3
luke
15

---

or like this:

Code:

---

ridley scott
alien
stanley cubrick
odyssey 2001
steven spielberg
independence day

---

Now I thought I can write one function to read them all, using templates:

Code:

---

template<int>
int convert(char * buf)
{
        return atoi(buf);
}

template<string>
string convert(char * buf)
{
        return string(buf);
}

template<class T1, class T2>
vector<pair<T1, T2> > load_vector(ifstream & f)
{
        vector<pair<T1, T2> > v;
        pair<T1, T2> p;

        char buf[128];

        while(!f.eof())
        {
                f.getline(buf, sizeof(buf));
                p.first = convert<T1>(buf);
                f.getline(buf, sizeof(buf));
                p.second = convert<T2>(buf);

                if(!p.first.empty())
                {
                        v.push_back(p);
                }
        }

        return v;
}

---

and I would call (say) load_vector<string, int> and get a nicely structured vector.
Not.
The compiler generates an error message, along the lines of

Quote:

---

'convert' : invalid template argument for 'function-parameter', compile-time evaluatable constant expression expected

---

, which I don't really understand. Isn't <string, int> constant enough? MSDN didn't help, either.
Thank you for your time :)

try something like load_vector<make_pair<string, int> >. not sure of the syntax.

You're not using templates correctly. Maybe something like this:

Code:

---

template<typename T>
T convert(char * buf);

template<>
int convert<int>(char * buf)
{
    return atoi(buf);
}

template<>
string convert<string>(char * buf)
{
    return string(buf);
}

---