Given an iterator of public scalars and an iterator of Options of group elements, compute either Some(Q), where Q = c_1 * E_1 + ... + c_n * E_n, if all points were Some(E_i), or else return undefined.
Given an iterator of public scalars and an iterator of Options of group elements, compute either Some(Q), where Q = c_1 * E_1 + ... + c_n * E_n, if all points were Some(E_i), or else return undefined.