fix SparseView: clean the nested matrix type
diff --git a/test/sparse_basic.cpp b/test/sparse_basic.cpp
index 3ebd592..8c93909 100644
--- a/test/sparse_basic.cpp
+++ b/test/sparse_basic.cpp
@@ -250,6 +250,13 @@
     VERIFY(countTrueNonZero==m2.nonZeros());
     VERIFY_IS_APPROX(m2, refM2);
   }
+  
+  // test sparseView
+  {
+    DenseMatrix refMat2 = DenseMatrix::Zero(rows, rows);
+    SparseMatrixType m2(rows, rows);
+    VERIFY_IS_APPROX(m2.eval(), refMat2.sparseView().eval());
+  }
 }
 
 void test_sparse_basic()