.. _program_listing_file_mesh_handle_mesh.hxx:

Program Listing for File mesh.hxx
=================================

|exhale_lsh| :ref:`Return to documentation for file <file_mesh_handle_mesh.hxx>` (``mesh_handle/mesh.hxx``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   /*
     This file is part of t8code.
     t8code is a C library to manage a collection (a forest) of multiple
     connected adaptive space-trees of general element classes in parallel.
   
     Copyright (C) 2025 the developers
   
     t8code is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or
     (at your option) any later version.
   
     t8code is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
   
     You should have received a copy of the GNU General Public License
     along with t8code; if not, write to the Free Software Foundation, Inc.,
     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
   */
   
   #ifndef T8_MESH_HXX
   #define T8_MESH_HXX
   
   #include <t8.h>
   #include <t8_forest/t8_forest_general.h>
   #include "element.hxx"
   #include <iterator>
   #include <memory>
   #include <vector>
   
   namespace t8_mesh_handle
   {
   
   template <class TMeshElement = element<>>
   class mesh {
    public:
     friend TMeshElement; 
     using mesh_const_iterator =
       typename std::vector<TMeshElement>::const_iterator; 
     mesh (t8_forest_t input_forest): m_forest (input_forest)
     {
       update_elements ();
     }
   
     t8_locidx_t
     get_num_local_elements () const
     {
       return t8_forest_get_local_num_leaf_elements (m_forest);
     }
   
     mesh_const_iterator
     begin () const
     {
       return m_elements.cbegin ();
     }
   
     mesh_const_iterator
     end () const
     {
       return m_elements.cend ();
     }
   
     const TMeshElement&
     operator[] (t8_locidx_t local_index) const
     {
       return m_elements[local_index];
     }
   
     t8_forest_t
     get_forest () const
     {
       return m_forest;
     }
   
     void
     set_forest (t8_forest_t input_forest)
     {
       m_forest = input_forest;
       update_elements ();
     }
   
    private:
     void
     update_elements ()
     {
       // Clear the element vector if already created.
       m_elements.clear ();
       m_elements.reserve (get_num_local_elements ());
       // Iterate through forest elements and fill the element vector with newly created mesh elements.
       for (t8_locidx_t itree = 0; itree < t8_forest_get_num_local_trees (m_forest); ++itree) {
         const t8_locidx_t num_elems = t8_forest_get_tree_num_leaf_elements (m_forest, itree);
         for (t8_locidx_t ielem = 0; ielem < num_elems; ++ielem) {
           m_elements.emplace_back (this, itree, ielem);
         }
       }
     }
   
     t8_forest_t m_forest;                 
     std::vector<TMeshElement> m_elements; 
   };
   
   }  // namespace t8_mesh_handle
   #endif /* !T8_MESH_HXX */