Silent overflow when parsing some 78-digit decimal numbers as uint256. #343
Description
The overflow checking code when parsing decimal numbers is not strict enough and some inputs cause silent overflow. For example, the number below is parsed as 9.
#include <iostream>
#include "./intx/include/intx/intx.hpp"
int main() {
const auto *const bad =
"115792089237316195423570985008687907853269984665640564039457584007913129639945";
auto const bad_num = intx::from_string<intx::uint256>(bad);
std::cout << bad << std::endl;
std::cout << intx::to_string(bad_num) << std::endl;
}