From 8b1f3e174587c8d15126ecad0d007d939e64802b Mon Sep 17 00:00:00 2001
From: Jose Luis Blanco-Claraco <joseluisblancoc@gmail.com>
Date: Mon, 27 Jul 2020 08:54:14 +0200
Subject: [PATCH] docs and missing traits

---
 gtsam/nonlinear/ExpressionFactor.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/gtsam/nonlinear/ExpressionFactor.h b/gtsam/nonlinear/ExpressionFactor.h
index 4bb8da685..85527f6dc 100644
--- a/gtsam/nonlinear/ExpressionFactor.h
+++ b/gtsam/nonlinear/ExpressionFactor.h
@@ -34,6 +34,9 @@ namespace gtsam {
  * such instances, the user should declare derived classes from this template,
  * implementing expresion(), serialize(), clone(), print(), and defining the
  * corresponding `struct traits<NewFactor> : public Testable<NewFactor> {}`.
+ *
+ * \tparam T Type for measurements.
+ *
  */
 template<typename T>
 class ExpressionFactor: public NoiseModelFactor {
@@ -279,6 +282,9 @@ class ExpressionFactor2 : public ExpressionFactor<T> {
         "ExpressionFactor", boost::serialization::base_object<ExpressionFactor<T> >(*this));
   }
 };
+/// traits
+template <typename T, typename A1, typename A2>
+struct traits<ExpressionFactor2<T,A1,A2>> : public Testable<ExpressionFactor2<T,A1,A2>> {};
 // ExpressionFactor2
 
 }// \ namespace gtsam