Hello Feng Feng, On 15.04.19 01:10, Feng Feng wrote:

I wonder if there is a way to convert the cl_N or GiNaC numeric type to c++ __float128 or long double? since the both also appear in CUBA.

I don't konw what long double is in CUBA, but in general it may vary between platforms. But conversion to and from fp128 types would make sense, IMO. In any case, this has little to do with GiNaC and is best discussed on cln-list@ginac.de (cross posting there). Best, -richy. -- <https://in.terlu.de/~kreckel/>