There are lots of magic in C and C++ that most people are unaware of or told never to do. But, that magic is used often by older programmers. For example, this is perfectly valid C++ (no compiler warnings or errors even with -Wall and -Wextra) it's roots are in C:

    #include <iostream>
    #include <boost/integer.hpp>

    int main()
    {
        // Notice these signed types are going into unsigned types!

        boost::uint64_t i = -9151314442815602945;
        std::cout << i << std::endl;

        unsigned int j = -327681234;
        std::cout << j << std::endl;

        return 0;
    }