47 struct Unifier {  struct
48   enum Winner { Neither, Right, Left };  // makes p ? Right : Neither a no-op
50   Unifier(const Graph& graph, Unification& unification)  in Unifier()  argument
53   bool operator()(Id id1, Id id2) {  in operator ()()
89   bool operator()(const std::optional<Id>& opt1,  in operator ()()
97   bool operator()(const std::vector<Id>& ids1, const std::vector<Id>& ids2) {  in operator ()()
106   bool operator()(const std::map<Key, Id>& ids1,  in operator ()()
122   Winner operator()(const Special& x1, const Special& x2) {  in operator ()()
127   Winner operator()(const PointerReference& x1,  in operator ()()
134   Winner operator()(const PointerToMember& x1, const PointerToMember& x2) {  in operator ()()
140   Winner operator()(const Typedef& x1, const Typedef& x2) {  in operator ()()
146   Winner operator()(const Qualified& x1, const Qualified& x2) {  in operator ()()
152   Winner operator()(const Primitive& x1, const Primitive& x2) {  in operator ()()
159   Winner operator()(const Array& x1, const Array& x2) {  in operator ()()
165   Winner operator()(const BaseClass& x1, const BaseClass& x2) {  in operator ()()
172   Winner operator()(const Method& x1, const Method& x2) {  in operator ()()
180   Winner operator()(const Member& x1, const Member& x2) {  in operator ()()
188   Winner operator()(const VariantMember& x1, const VariantMember& x2) {  in operator ()()
195   Winner operator()(const StructUnion& x1, const StructUnion& x2) {  in operator ()()
210   Winner operator()(const Enumeration& x1, const Enumeration& x2) {  in operator ()()
223   Winner operator()(const Variant& x1, const Variant& x2) {  in operator ()()
231   Winner operator()(const Function& x1, const Function& x2) {  in operator ()()
237   Winner operator()(const ElfSymbol& x1, const ElfSymbol& x2) {  in operator ()()
254   Winner operator()(const Interface& x1, const Interface& x2) {  in operator ()()
260   Winner Mismatch() {  in Mismatch()
264   Id Find(Id id) {  in Find()
276   const Graph& graph;
277   Unification& unification;
278   std::unordered_set<Pair> seen;
279   std::unordered_map<Id, Id> mapping;