====== String to integer & integer to string ======

===== String to integer =====

<code cpp>
int str2int (const std::string &str)
{
    std::stringstream ss(str);
    int n;
    ss >> n;
    return n;
}
</code>

===== Integer to string =====

<code cpp>
string int2str (int n)
{
    std::stringstream ss;
    ss << n;
    return ss.str();
}
</code>