gistfile1.txt

size_t
number_parser::
parse(
    number& result,
    char const* begin,
    char const* end,
    error_code& ec)
{
    char_stream cs(begin, end);

    bool neg;
    uint64_t m64;
    int sig;

    neg = consume(cs, '-');
    if(cs.peek() == '0')
    {
        m64 = 0;
    }
    else if(BOOST_JSON_LIKELY(
        cs.peek() >= '1' &&
        cs.peek() <= '9'))
    {
        m64 = static_cast<uint64_t>(
            cs.get() - '0');
        if(neg)
        {
            while(
                cs.peek() >= '0' &&
                cs.peek() <= '9')
            {
            }
        }
        else
        {
            while(
                cs.peek() >= '0' &&
                cs.peek() <= '9')
            {
                if(BOOST_JSON_UNLIKELY(
                    //     18446744073709551615 UINT64_MAX
                    m64 >= 1844674407370955161))
                {
                    if(BOOST_JSON_LIKELY(
                        m64 != 1844674407370955161) ||
                        cs.peek() == '5')
                    {
                        // use double
                        break;
                    }
                }
                m64 = m64 * 10 + static_cast<
                    unsigned int>(cs.get() - '0');
            }
        }
    }
    else
    {
        return 0;
    }
    return p - begin;
}