--- trunk/src/utils/Algorithm.hpp	2010/05/10 17:28:26	1442
+++ trunk/src/utils/Algorithm.hpp	2012/08/22 02:28:28	1782
@@ -36,7 +36,8 @@
  * [1]  Meineke, et al., J. Comp. Chem. 26, 252-271 (2005).             
  * [2]  Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006).          
  * [3]  Sun, Lin & Gezelter, J. Chem. Phys. 128, 24107 (2008).          
- * [4]  Vardeman & Gezelter, in progress (2009).                        
+ * [4]  Kuang & Gezelter,  J. Chem. Phys. 133, 164101 (2010).
+ * [5]  Vardeman, Stocker & Gezelter, J. Chem. Theory Comput. 7, 834 (2011).
  */
 
 #include <functional>
@@ -63,8 +64,8 @@ namespace OpenMD {
 
 
   template<typename T>
-  struct logical_xor :public std::binary_function<T, T, bool> {
-    RealType operator()(T x, T y) { return x ^ y; }
+  struct logical_xor : public std::binary_function<T, T, bool> {
+    T operator()(const T& x, const T& y) { return x ^ y; }
   };
 
 }