/**
* Implementation of the interface in
* @ref{Mapping}.
+ *
+ * Description of effects:
+ * @begin{itemize}
+ * @item if @p{update_q_points}
+ * is required, the output will
+ * contain
+ * @p{update_transformation_values}. This
+ * computes the values of the
+ * transformation basis
+ * polynomials at the unit cell
+ * quadrature points.
+ * @item if any of
+ * @p{update_covariant_transformation},
+ * @p{update_contravariant_transformation},
+ * @p{update_JxW_values},
+ * @p{update_boundary_forms},
+ * @p{update_normal_vectors} is
+ * required, the output will
+ * contain
+ * @p{update_transformation_gradients}
+ * to compute derivatives of the
+ * transformation basis
+ * polynomials.
+ * @end{itemize}
*/
- virtual UpdateFlags update_once (const UpdateFlags) const;
+ virtual UpdateFlags update_once (const UpdateFlags flags) const;
/**
* Implementation of the interface in
* @ref{Mapping}.
+ *
+ * Description of effects if
+ * @p{flags} contains:
+ * @begin{itemize}
+ * @item p{update_q_points} is
+ * copied to the output to
+ * compute the quadrature points
+ * on the real cell.
+ * @item p{update_JxW_values} is
+ * copied and requires
+ * @p{update_boundary_forms} on
+ * faces. The latter, because the
+ * surface element is just the
+ * norm of the boundary form.
+ * @item p{update_normal_vectors}
+ * is copied and requires
+ * @p{update_boundary_forms}. The
+ * latter, because the normal
+ * vector is the normalized
+ * boundary form.
+ * @item
+ * p{update_covariant_transformation}
+ * is copied and requires
+ * @p{update_contravariant_transformation},
+ * since it is computed as the
+ * inverse of the latter.
+ * @item p{update_JxW_values} is
+ * copied and requires
+ * @p{update_contravariant_transformation},
+ * since it is computed as one
+ * over determinant of the
+ * latter.
+ * @item p{update_boundary_forms}
+ * is copied and requires
+ * @p{update_contravariant_transformation},
+ * since the boundary form is
+ * computed as the contravariant
+ * image of the normal vector to
+ * the unit cell.
+ * @end{itemize}
*/
- virtual UpdateFlags update_each (const UpdateFlags) const;
+ virtual UpdateFlags update_each (const UpdateFlags flags) const;
/**
* Storage for internal data of