Question

why is this code not giving me correct values for large numbers? does it have something to do with me using numbers larger than 32 bits? if so, how do i get my function to accept values of any bit size? would i just overload the function? that seems a bit of a waste of space

std::string makehex(unsigned int value, unsigned int size = 2){
    std::string out;
    while (value > 0){
        out = h[value % 16] + out;
        value /= 16;
    }
    while (out.size() < size)
        out = "0" + out;
    return out;
}

edit: usage:

std::string value = makehex(30, 5);
std::cout << value; // 0001e

Answer 1

template<typename T>
std::string makehex(T value, const unsigned size = 2 * sizeof(T))
{
    std::string out(size, '0');
    while (value && size){
        out[--size] = "0123456789abcdef"[value & 0x0f];
        value >>= 4;
    }
    return out;
}

Demo: http://ideone.com/v04Vo