Initial implementation of lpxclient

luprex/core/cpp/world-core.cpp

@@ -732,12 +732,14 @@ void World::deserialize(StreamBuffer *sb) {
 }
 
 void World::snapshot() {
-    snapshot_.clear();
+    assert(snapshot_.empty());
     serialize(&snapshot_);
+    assert(!snapshot_.empty());
 }
 
 void World::rollback() {
     assert(!snapshot_.empty());
     deserialize(&snapshot_);
+    assert(snapshot_.empty());
 }