Index: lib/Format/Format.cpp
===================================================================
--- lib/Format/Format.cpp
+++ lib/Format/Format.cpp
@@ -676,6 +676,12 @@
   typedef std::priority_queue<QueueItem, std::vector<QueueItem>,
                               std::greater<QueueItem> > QueueType;
 
+  struct Compare {
+    bool operator()(LineState *obj1, LineState *obj2) const {
+      return *obj1 < *obj2;
+    }
+  };
+
   /// \brief Analyze the entire solution space starting from \p InitialState.
   ///
   /// This implements a variant of Dijkstra's algorithm on the graph that spans
@@ -683,7 +689,7 @@
   /// find the shortest path (the one with lowest penalty) from \p InitialState
   /// to a state where all tokens are placed.
   unsigned analyzeSolutionSpace(LineState &InitialState) {
-    std::set<LineState> Seen;
+    std::set<LineState *, Compare> Seen;
 
     // Insert start element into queue.
     StateNode *Node =
@@ -701,7 +707,7 @@
       }
       Queue.pop();
 
-      if (!Seen.insert(Node->State).second)
+      if (!Seen.insert(&Node->State).second)
         // State already examined with lower penalty.
         continue;