Fix bug #626: add assertion on input ranges for coeff* and insert members for sparse objects
diff --git a/test/sparse_basic.cpp b/test/sparse_basic.cpp
index 6954ba7..8fc1904 100644
--- a/test/sparse_basic.cpp
+++ b/test/sparse_basic.cpp
@@ -91,6 +91,10 @@
         VERIFY_IS_APPROX(m.row(r) + m.row(r), refMat.row(r) + refMat.row(r));
       }
       */
+      
+      // test assertion
+      VERIFY_RAISES_ASSERT( m.coeffRef(-1,1) = 0 );
+      VERIFY_RAISES_ASSERT( m.coeffRef(0,m.cols()) = 0 );
     }
 
     // test insert (inner random)