I've seen into the code and remembered. No. I cannot use the seed, because a parallel code from aaGetHash cannot use seed. aaGetHash is a version for calculating hash of AA using pointer and typeinfo. TypeInfo.getHash doesn't accept seed argument and aaGetHashStatic must follow it. This is a trouble. Some functions must perform similar things with different data. One version accept only pointer and TypeInfo (and cannot be evaluated at compile-time, potentially slower but used by aaA.d code), another version accept auto ref to value and compile-time parameter T. Both versions must return identical value, but do different actions.