From b97d66b04a9f1eab1c73280ab7f7b7faca586a40 Mon Sep 17 00:00:00 2001
From: Frank Dellaert <frank@skyd.io>
Date: Sat, 11 Jul 2015 16:34:10 -0700
Subject: [PATCH] Assert type T is Testable

---
 gtsam/nonlinear/ExpressionFactor.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/gtsam/nonlinear/ExpressionFactor.h b/gtsam/nonlinear/ExpressionFactor.h
index c8137a098..8a6f28713 100644
--- a/gtsam/nonlinear/ExpressionFactor.h
+++ b/gtsam/nonlinear/ExpressionFactor.h
@@ -31,6 +31,7 @@ namespace gtsam {
  */
 template<typename T>
 class ExpressionFactor: public NoiseModelFactor {
+  BOOST_CONCEPT_ASSERT((IsTestable<T>));
 
 protected: