Fix compilation with gcc-4.9.4

Closes: https://github.com/dealii/dealii/issues/10146

diff --git a/include/deal.II/matrix_free/mapping_info.templates.h b/include/deal.II/matrix_free/mapping_info.templates.h
index b7d7b5bae93218cd69ac0a66257f6d1d44f98b0c..39fc06fea409a3bd58eaa5770cac77a11c92ba18 100644 (file)
--- a/include/deal.II/matrix_free/mapping_info.templates.h
+++ b/include/deal.II/matrix_free/mapping_info.templates.h
@@ -2565,11 +2565,13 @@ namespace internal
       // evaluate the geometry in double precision; thus, for floats we need
       // to do things in two sweeps and convert the final result.
       constexpr unsigned int n_lanes = VectorizedArrayType::size();
+
       using VectorizedDouble =
         VectorizedArray<double,
-                        ((std::is_same<Number, float>::value && n_lanes > 1) ?
-                           n_lanes / 2 :
-                           n_lanes)>;
+                        ((std::is_same<Number, float>::value &&
+                          VectorizedArrayType::size() > 1) ?
+                           VectorizedArrayType::size() / 2 :
+                           VectorizedArrayType::size())>;
 
       // Create a ShapeInfo object to provide the necessary interpolators to
       // the various quadrature points. Note that it is initialized with the