[GiNaC-list] Poles and zeros

Hi all, I'm trying to calculate the poles and zeros of a polynomial and I thought some functions to do this, but I can't find anything anymore. Is there any easy option currently to do this? If not, where would I start implementing this? I don't really grok the GiNaC structure. I'm happy to write a pull request (if I get it done). Kind regards, Patrick