PTN_LEAF_POSITION
const pt_bitoff_t leaf_position = PTN_LEAF_POSITION(ptn);
KASSERT(PTN_LEAF_POSITION(mask) == id->id_parent_slot);
KASSERT(PT_BRANCH_P(node) || id->id_parent_slot == PTN_LEAF_POSITION(ptn));
KASSERT(PT_BRANCH_P(node) || id->id_parent_slot == PTN_LEAF_POSITION(PT_NODE(node)));
KASSERT(PTN_LEAF_POSITION(leaf) == id->id_parent_slot);
KASSERT(PTN_LEAF_POSITION(ptn) == id.id_parent_slot);
const pt_slot_t leaf_slot = PTN_LEAF_POSITION(target);
PTN__EXTRACT((ptn)->ptn_nodedata, PTN_LEAF_POSITION)
PTN__INSERT((ptn)->ptn_nodedata, PTN_LEAF_POSITION, slot)