From d1246bfe987be28118c805f6232ffcb188ec1522 Mon Sep 17 00:00:00 2001
From: Alex Cunningham <alexgcunningham@gmail.com>
Date: Sun, 27 Jan 2013 20:12:22 +0000
Subject: [PATCH] Added empty() to BayesTree

---
 gtsam/inference/BayesTree.h             | 5 +++++
 gtsam/inference/tests/testBayesTree.cpp | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/gtsam/inference/BayesTree.h b/gtsam/inference/BayesTree.h
index 3982a5987..8e09da31d 100644
--- a/gtsam/inference/BayesTree.h
+++ b/gtsam/inference/BayesTree.h
@@ -162,6 +162,11 @@ namespace gtsam {
         return 0;
     }
 
+    /** Check if there are any cliques in the tree */
+    inline bool empty() const {
+      return nodes_.empty();
+    }
+
     /** return nodes */
     const Nodes& nodes() const { return nodes_; }
 
diff --git a/gtsam/inference/tests/testBayesTree.cpp b/gtsam/inference/tests/testBayesTree.cpp
index bbc02e07c..a29b609a5 100644
--- a/gtsam/inference/tests/testBayesTree.cpp
+++ b/gtsam/inference/tests/testBayesTree.cpp
@@ -93,6 +93,7 @@ TEST( BayesTree, constructor )
 
   // Check Size
   LONGS_EQUAL(4,bayesTree.size());
+  EXPECT(!bayesTree.empty());
 
   // Check root
   boost::shared_ptr<IndexConditional> actual_root = bayesTree.root()->conditional();
@@ -155,6 +156,7 @@ TEST( BayesTree, removePath )
       E(new IndexConditional(_E_, _B_)),
       F(new IndexConditional(_F_, _E_));
   SymbolicBayesTree bayesTree;
+  EXPECT(bayesTree.empty());
 //  Ordering ord; ord += _A_,_B_,_C_,_D_,_E_,_F_;
   SymbolicBayesTree::insert(bayesTree, A);
   SymbolicBayesTree::insert(bayesTree, B);