From 27a4a748cb5cce6f68b6127d6c165a9808b8b2a7 Mon Sep 17 00:00:00 2001
From: Hauke Heibel <hauke.heibel@gmail.com>
Date: Thu, 22 Apr 2010 13:56:06 +0200
Subject: [PATCH] MSVC runs into problems when a forward declaration is using a
 different template type name than the actual declaration. This fixes the
 recent issues we observed on MSVC systems.

---
 Eigen/src/Core/util/ForwardDeclarations.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Eigen/src/Core/util/ForwardDeclarations.h b/Eigen/src/Core/util/ForwardDeclarations.h
index 9379b64f8..9434bfd14 100644
--- a/Eigen/src/Core/util/ForwardDeclarations.h
+++ b/Eigen/src/Core/util/ForwardDeclarations.h
@@ -54,13 +54,13 @@ template<typename MatrixType> class Minor;
 // is used as default template parameter value here, it gets mis-evaluated as just ei_traits<MatrixType>::Flags
 // Moreover, adding brackets tends to give compilation errors with MSVC.
 // Solution: defer that to a helper struct.
-template<typename MatrixType>
+template<typename XprType>
 struct ei_block_direct_access_status
 {
-  enum { ret = ei_traits<MatrixType>::Flags&DirectAccessBit ? HasDirectAccess : NoDirectAccess };
+  enum { ret = ei_traits<XprType>::Flags&DirectAccessBit ? HasDirectAccess : NoDirectAccess };
 };
-template<typename MatrixType, int BlockRows=Dynamic, int BlockCols=Dynamic,
-         int _DirectAccessStatus = ei_block_direct_access_status<MatrixType>::ret> class Block;
+template<typename XprType, int BlockRows=Dynamic, int BlockCols=Dynamic,
+         int _DirectAccessStatus = ei_block_direct_access_status<XprType>::ret> class Block;
 
 template<typename MatrixType, int Size=Dynamic> class VectorBlock;
 template<typename MatrixType> class Transpose;