From 1046ea7a89bd8023663b51c73305adc945a6363a Mon Sep 17 00:00:00 2001
From: Jitse Niesen <jitse@maths.leeds.ac.uk>
Date: Mon, 7 Apr 2014 13:49:51 +0100
Subject: [PATCH] doc: Note that dm2 = sm1 + dm1 is not possible (see bug
 #632).

---
 doc/TutorialSparse.dox | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/doc/TutorialSparse.dox b/doc/TutorialSparse.dox
index 835c59354..fa2a3ad8b 100644
--- a/doc/TutorialSparse.dox
+++ b/doc/TutorialSparse.dox
@@ -253,12 +253,15 @@ SparseMatrix<double> A, B;
 B = SparseMatrix<double>(A.transpose()) + A;
 \endcode
 
-Binary coefficient wise operators can also mix sparse and dense expressions:
+Some binary coefficient-wise operators can also mix sparse and dense expressions:
 \code
 sm2 = sm1.cwiseProduct(dm1);
-dm2 = sm1 + dm1;
+dm1 += sm1;
 \endcode
 
+However, it is not yet possible to add a sparse and a dense matrix as in <tt>dm2 = sm1 + dm1</tt>.
+Please write this as the equivalent <tt>dm2 = dm1; dm2 += sm1</tt> (we plan to lift this restriction
+in the next release of %Eigen).
 
 %Sparse expressions also support transposition:
 \code