+/**
+ * Flags to control the behavior of gcd() and friends
+ */
+struct gcd_options
+{
+ enum {
+ /**
+ * Usually GiNaC tries heuristic GCD first, because typically
+ * it's much faster than anything else. Even if heuristic
+ * algorithm fails, the overhead is negligible w.r.t. cost
+ * of computing the GCD by some other method. However, some
+ * people dislike it, so here's a flag which tells GiNaC
+ * to NOT use the heuristic algorithm.
+ */
+ no_heur_gcd = 2,
+ /**
+ * GiNaC tries to avoid expanding expressions when computing
+ * GCDs. This is a good idea, but some people dislike it.
+ * Hence the flag to disable special handling of partially
+ * factored polynomials. DON'T SET THIS unless you *really*
+ * know what are you doing!
+ */
+ no_part_factored = 4,
+ /**
+ * By default GiNaC uses modular GCD algorithm. Typically
+ * it's much faster than PRS (pseudo remainder sequence)
+ * algorithm. This flag forces GiNaC to use PRS algorithm
+ */
+ use_sr_gcd = 8
+
+ };
+};
+