LocalDensity: use `ctype` for `x` entries

dune/elasticity/materials/exphenckydensity.hh

@@ -8,7 +8,7 @@
 
 namespace Dune::Elasticity {
 
-template<int dim, class field_type = double>
+template<int dim, class field_type = double, class ctype = double>
 class ExpHenckyDensity final
   : public LocalDensity<dim,field_type>
 {
@@ -40,7 +40,7 @@ public:
   * \param x Position of the gradient
   * \param gradient Deformation gradient
   */
-  field_type operator() (const FieldVector<field_type,dim>& x, const FieldMatrix<field_type,dim,dim>& gradient) const
+  field_type operator() (const FieldVector<ctype,dim>& x, const FieldMatrix<field_type,dim,dim>& gradient) const
   {
     /////////////////////////////////////////////////////////
     // compute C = F^TF