BigInt derived from GMP MP. And it doesn't require additional dependencies. Bigint is a simplified version. Convenient syntax, OOP makes the code easy to read.
#include <iostream>
#include "bigint.hpp"
using namespace bigint;
int main(){
BigInt a, b, c;
a = 1024;
b = "1024";
c = a + b;
std::cout << "a + b = " << c << std::endl;
...
c = BigInt::pow(a, b);
std::cout << "Expower a ^ b = " << c << std::endl;
return 0;
}