From 4ba0ec5e0e82e970c4918ba13f5d2090f9a32f4a Mon Sep 17 00:00:00 2001
From: Hauke Heibel <hauke.heibel@gmail.com>
Date: Tue, 4 Jan 2011 15:35:50 +0100
Subject: [PATCH] Fixed #148 where a const-accessor for coefficients was
 missing in the MatrixWrapper.

---
 Eigen/src/Core/ArrayWrapper.h | 5 +++++
 Eigen/src/Core/Block.h        | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/Eigen/src/Core/ArrayWrapper.h b/Eigen/src/Core/ArrayWrapper.h
index d5b8c6804..f6b7f90a4 100644
--- a/Eigen/src/Core/ArrayWrapper.h
+++ b/Eigen/src/Core/ArrayWrapper.h
@@ -160,6 +160,11 @@ class MatrixWrapper : public MatrixBase<MatrixWrapper<ExpressionType> >
       return m_expression.const_cast_derived().coeffRef(row, col);
     }
 
+    inline const Scalar& coeffRef(Index row, Index col) const
+    {
+      return m_expression.derived().coeffRef(row, col);
+    }
+
     inline const CoeffReturnType coeff(Index index) const
     {
       return m_expression.coeff(index);
diff --git a/Eigen/src/Core/Block.h b/Eigen/src/Core/Block.h
index 00d5d8b4e..de384b025 100644
--- a/Eigen/src/Core/Block.h
+++ b/Eigen/src/Core/Block.h
@@ -174,7 +174,7 @@ template<typename XprType, int BlockRows, int BlockCols, bool InnerPanel, bool H
 
     inline const Scalar& coeffRef(Index row, Index col) const
     {
-      return m_xpr.const_cast_derived()
+      return m_xpr.derived()
                .coeffRef(row + m_startRow.value(), col + m_startCol.value());
     }