struct UnionOps
{
static BoundingBox<T, D> combine_aabb(const BoundingBox<T, D> &a, const BoundingBox<T, D> &b) { return a|b; }
+ static Coverage combine_coverage(Coverage a, Coverage b) { return std::max(a, b); }
static bool shortcircuit(bool c) { return c; }
};