graph/internal/...: update for int64 IDs

graph/internal/set/same.go

@@ -25,3 +25,12 @@ func same(a, b Nodes) bool {
 func intsSame(a, b Ints) bool {
 	return *(*uintptr)(unsafe.Pointer(&a)) == *(*uintptr)(unsafe.Pointer(&b))
 }
+
+// int64sSame determines whether two sets are backed by the same store. In the
+// current implementation using hash maps it makes use of the fact that
+// hash maps are passed as a pointer to a runtime Hmap struct. A map is
+// not seen by the runtime as a pointer though, so we use unsafe to get
+// the maps' pointer values to compare.
+func int64sSame(a, b Int64s) bool {
+	return *(*uintptr)(unsafe.Pointer(&a)) == *(*uintptr)(unsafe.Pointer(&b))
+}