From dde5a95e892172936b9962accb6746dfb2eb4a28 Mon Sep 17 00:00:00 2001
From: Luca Heltai <luca.heltai@sissa.it>
Date: Fri, 6 Apr 2018 15:01:51 +0200
Subject: [PATCH] Add clone method for Manifold and FlatManifold

---
 include/deal.II/grid/manifold.h | 12 ++++++++++++
 source/grid/manifold.cc         |  9 +++++++++
 2 files changed, 21 insertions(+)

diff --git a/include/deal.II/grid/manifold.h b/include/deal.II/grid/manifold.h
index 34fcc77462..fe0f8aa237 100644
--- a/include/deal.II/grid/manifold.h
+++ b/include/deal.II/grid/manifold.h
@@ -350,6 +350,13 @@ public:
    */
   virtual ~Manifold () = default;
 
+  /**
+   * Return a copy of this manifold.
+   *
+   * Every derived class should implement this operation in a sensible manner.
+   */
+  virtual std::unique_ptr<Manifold<dim,spacedim> > clone() const = 0;
+
   /**
    * @name Computing the location of points.
    */
@@ -692,6 +699,11 @@ public:
   FlatManifold (const Tensor<1,spacedim> &periodicity = Tensor<1,spacedim>(),
                 const double tolerance=1e-10);
 
+  /**
+   * Return a copy of this manifold.
+   */
+  virtual std::unique_ptr<Manifold<dim,spacedim> > clone() const override;
+
   /**
    * Let the new point be the average sum of surrounding vertices.
    *
diff --git a/source/grid/manifold.cc b/source/grid/manifold.cc
index 9a74d866a3..94b0f266e2 100644
--- a/source/grid/manifold.cc
+++ b/source/grid/manifold.cc
@@ -512,6 +512,15 @@ FlatManifold<dim,spacedim>::FlatManifold (const Tensor<1,spacedim> &periodicity,
 
 
 
+template<int dim, int spacedim>
+std::unique_ptr<Manifold<dim, spacedim> >
+FlatManifold<dim,spacedim>::clone() const
+{
+  return std::unique_ptr<Manifold<dim,spacedim> >(new FlatManifold<dim,spacedim>(periodicity, tolerance));
+}
+
+
+
 template <int dim, int spacedim>
 Point<spacedim>
 FlatManifold<dim, spacedim>::
-- 
2.39.5