From a34a216e82290eb78e7afe7539976f1650ccbd76 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Thu, 12 May 2011 23:40:19 +0200
Subject: [PATCH] AutoDiff: add one missing operator- version

---
 unsupported/Eigen/src/AutoDiff/AutoDiffScalar.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/unsupported/Eigen/src/AutoDiff/AutoDiffScalar.h b/unsupported/Eigen/src/AutoDiff/AutoDiffScalar.h
index 1a797d560..4fc003d63 100644
--- a/unsupported/Eigen/src/AutoDiff/AutoDiffScalar.h
+++ b/unsupported/Eigen/src/AutoDiff/AutoDiffScalar.h
@@ -216,6 +216,11 @@ class AutoDiffScalar
       return *this;
     }
 
+    inline const AutoDiffScalar<DerType&> operator-(const Scalar& b) const
+    {
+      return AutoDiffScalar<DerType&>(m_value - b, m_derivatives);
+    }
+
     friend inline const AutoDiffScalar<DerType&> operator-(const Scalar& a, const AutoDiffScalar& b)
     {
       return AutoDiffScalar<DerType&>(a - b.value(), b.derivatives());