There have been some early-stage proposals for standardization of big integers in C++, but not enough interest, it seems. For a recent (current) example, http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0539r4.html whose authors have been persistent with it (it's the 4th revision), so hopefully they'll come back with it early in C++23 cycle