Here is my bigint struct in c++.
https://paste.ubuntu.com/p/Kb2Cwtk6Bg/ (new link is available)
enjoy it :))
upd1 : I added bitwise operator and shift. here is new link.
upd2 : I added popcount, ctz and tutorial to how to use change base function :D.
you can use the new code below :
(any suggestion please comment)