fix both compilation and previous fix : now 'basicstuff' passes again.
(Gael: i dont think you meant removing this setIdentity(), did you?)
diff --git a/Eigen/src/Core/MatrixBase.h b/Eigen/src/Core/MatrixBase.h
index 5ceb02c..81c7cef 100644
--- a/Eigen/src/Core/MatrixBase.h
+++ b/Eigen/src/Core/MatrixBase.h
@@ -247,6 +247,7 @@
     const DiagonalWrapper<Derived> asDiagonal() const;
 
     Derived& setIdentity();
+    Derived& setIdentity(int rows, int cols);
 
     bool isIdentity(RealScalar prec = dummy_precision<Scalar>()) const;
     bool isDiagonal(RealScalar prec = dummy_precision<Scalar>()) const;