IsNumber.cpp

/* 
 Losely based on http://stackoverflow.com/questions/18154630/c-see-if-argument-is-numeric 
 and other related answers on stackoverflow.com
 */
auto IsNumber(const std::string& maybeNumber) -> bool
{
    auto decimal = false;
    for (char c : maybeNumber)
    {
        if (c == '.' && !decimal)
            decimal = true;
        else if (c == '-')
            continue;
        else if (!std::isdigit(c))
            return false;
    }
    return true;
};