Base Conversion Problem

[Labdabeta]

I made a header file to convert strings to numbers of base X. That is I want:

int num=B<16,int>("FFF");

To equal:

int num=0xFFF;

Here is the code so far:

#include <string>
int numb(char in)
{
    if (in>='0'&&in<='9')
        return in-'0';
    else if (in>='a'&&in<='z')
        return in-'a';
    else if (in>='A'&&in<='Z')
        return in-'A';
}
template <typename T>
T pow(T n1, T n2)
{
    T temp=n1;
    for (T i=0; i<n2; i++)
        temp*=n1;
    return temp;
}
template <const int base,typename T>
T B(std::string num)
{
    T ret=0;
    for (int i=0; i<num.length(); i++)
        ret+=numb(num[num.length()-i-1])*pow(T(base),T(i));
    return ret;
}

The problem is that it isn't working. Can anybody see why?

[Labdabeta]

Nevermind, I posted too soon. Just figured it out:

#include <string>
int numb(char in)
{
    if (in>='0'&&in<='9')
        return in-'0';
    else if (in>='a'&&in<='z')
        return in-'a';
    else if (in>='A'&&in<='Z')
        return in-'A';
    else
        return 0;
}
template <typename T>
T pow(T n1, T n2)
{
    if (n2==0)
        return 1;
    else if (n2==1)
        return n1;
    else
        return pow<T>(n1, n2-1)*n1;
}
template <const int base,typename T>
T B(std::string num)
{
    T ret=0;
    for (int i=0; i<num.length(); i++)
        ret+=numb(num[num.length()-i-1])*pow(T(base),T(i));
    return ret;
}