Line data    Source code

       1              : // *****************************************************************************
       2              : /*!
       3              :   \file      src/Mesh/Around.hpp
       4              :   \copyright 2012-2015 J. Bakosi,
       5              :              2016-2018 Los Alamos National Security, LLC.,
       6              :              2019-2021 Triad National Security, LLC.,
       7              :              2022-2025 J. Bakosi
       8              :              All rights reserved. See the LICENSE file for details.
       9              :   \brief     Helper class for iterating through linked lists of derived data
      10              :   \details   Helper class for iterating through every item in a linked list data
      11              :     structure derived from unstructured mesh connectivity.
      12              :   \see src/Mesh/DerivedData.h
      13              : */
      14              : // *****************************************************************************
      15              : #ifndef Around_h
      16              : #define Around_h
      17              : 
      18              : #include <vector>
      19              : #include <map>
      20              : #include <utility>
      21              : #include <cstddef>
      22              : #include "Types.hpp"
      23              : #include "Fields.hpp"
      24              : #include "UnsMesh.hpp"
      25              : 
      26              : namespace tk {
      27              : 
      28              : //! \brief Helper class simplifying client code for iterating on entries
      29              : //!   surrounding entries via linked lists derived from unstructured mesh
      30              : //!   connectivity
      31              : class Around {
      32              : 
      33              :   private:
      34              :     //! Linked list type: T1: item list, T2: index list
      35              :     using List =
      36              :       std::pair< std::vector< std::size_t >, std::vector< std::size_t > >;
      37              : 
      38              :     //! Non-const iterator to the item list in List::T1
      39              :     using iterator = List::first_type::iterator;
      40              : 
      41              :     //! Const iterator to the item list in List::T1
      42              :     using const_iterator = List::first_type::const_iterator;
      43              : 
      44              :     //! Difference type for iterator/pointer arithmetics
      45              :     using diff_type = List::first_type::difference_type;
      46              : 
      47              :   public:
      48              :     //! Constructor
      49              :     //! \param[in] list Linked list (vectors) storing derived data
      50              :     //! \param[in] idx Index of entry whose surrounding items we will iterate on
      51       942550 :     explicit Around( const List& list, std::size_t idx ) :
      52       942550 :       m_list( list ), m_idx( idx ) {}
      53              : 
      54              :     //! Const iterator to the beginning of the entries of surrounding entries
      55              :     //! \return Iterator to the beginning of the entries of surrounding entries
      56              :     //! \note This class does not allow modifing the underlying linked list, so
      57              :     //!   the begin/end iterators are aliased to cbegin/cend.
      58       942592 :     const_iterator begin() const noexcept { return this->cbegin(); }
      59              : 
      60              :     //! Const iterator to the entry after the last of the surrounding entries
      61              :     //! \return Iterator to the entry after the last of the surrounding entries
      62              :     //! \note This class does not allow modifing the underlying linked list, so
      63              :     //!   the begin/end iterators are aliased to cbegin/cend.
      64       942592 :     const_iterator end() const noexcept { return this->cend(); }
      65              : 
      66              :     //! Iterator to the beginning of the entries of surrounding entries
      67              :     //! \return Iterator to the beginning of the entries of surrounding entries
      68       942606 :     const_iterator cbegin() const noexcept {
      69       942606 :       return m_list.first.cbegin() +
      70       942606 :              static_cast< diff_type >( m_list.second[m_idx] + 1 );
      71              :     }
      72              : 
      73              :     //! Iterator to the entry after the last of the surrounding entries
      74              :     //! \return Iterator to the entry after the last of the surrounding entries
      75       942606 :     const_iterator cend() const noexcept {
      76       942606 :       return m_list.first.cbegin() +
      77       942606 :              static_cast< diff_type >( m_list.second[m_idx+1] + 1 );
      78              :     }
      79              : 
      80              :   private:
      81              :     const List& m_list; //!< Linked list to iterate in
      82              :     std::size_t m_idx;  //!< Index whose surrounding entries to iterate on
      83              : };
      84              : 
      85              : } // tk::
      86              : 
      87              : #endif // Around_h