gridview.hh

// SPDX-FileCopyrightText: Copyright (C) DUNE Project contributors, see file LICENSE.md in module root
// SPDX-License-Identifier: LicenseRef-GPL-2.0-only-with-DUNE-exception
// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
// vi: set et ts=4 sw=2 sts=2:
#ifndef DUNE_GRID_COMMON_GRIDVIEW_HH
#define DUNE_GRID_COMMON_GRIDVIEW_HH
 
#include <typeinfo>
 
#include <dune/common/std/type_traits.hh>
#include <dune/common/iteratorrange.hh>
#include <dune/common/parallel/future.hh>
 
#include <dune/geometry/type.hh>
 
#include <dune/grid/common/datahandleif.hh>
#include <dune/grid/common/rangegenerators.hh>
 
namespace Dune
{
 
  template< int, int, class, class >
  class GridDefaultImplementation;
 
 
 
  template< class ViewTraits >
  class GridView
  {
    typedef GridView< ViewTraits > ThisType;
 
  public:
    typedef typename ViewTraits :: GridViewImp Implementation;
 
    typedef typename ViewTraits :: GridViewImp GridViewImp;
 
    typedef ViewTraits Traits;
 
    typedef typename Traits :: Grid Grid;
 
    typedef typename Traits :: IndexSet IndexSet;
 
    typedef typename Traits :: Intersection Intersection;
 
    typedef typename Traits :: IntersectionIterator IntersectionIterator;
 
  protected:
    template <class T>
    using Communication_t = typename T :: Communication;
    template <class T>
    using DeprecatedCollectiveCommunication_t = typename T :: CollectiveCommunication;
 
  public:
    // if this line produces a warning then the Communication typedef is missing
    // in the Traits
    using Communication = detected_or_fallback_t<DeprecatedCollectiveCommunication_t,
                                                 Communication_t, Traits>;
 
    using CollectiveCommunication [[deprecated("CollectiveCommunication is deprecated, use Communication instead!")]] = Communication;
 
    template< int cd >
    struct Codim {
      typedef typename Traits :: template Codim<cd> :: Iterator Iterator;
 
      typedef typename Traits :: template Codim<cd> :: Entity Entity;
 
      typedef typename Traits :: template Codim<cd> :: Geometry Geometry;
 
      typedef typename Traits :: template Codim<cd> :: LocalGeometry LocalGeometry;
 
      template< PartitionIteratorType pit >
      struct Partition
      {
        typedef typename Traits :: template Codim< cd >
        :: template Partition< pit > :: Iterator Iterator;
      };
    }; //: public Traits :: template Codim<cd> {};
 
    constexpr static bool conforming = Traits :: conforming;
 
    typedef typename Grid::ctype ctype;
 
    constexpr static int dimension = Grid :: dimension;
 
    constexpr static int dimensionworld = Grid :: dimensionworld;
 
  public:
 
    //===========================================================
    //===========================================================
    GridView ( const Implementation &imp )
      : impl_( imp )
    {}
 
    GridView ( const ThisType &other )
      : impl_( other.impl_ )
    {}
 
    ThisType &operator= ( const ThisType &other )
    {
      impl_ = other.impl_;
      return *this;
    }
 
  public:
    const Grid &grid () const
    {
      return impl().grid();
    }
 
    const IndexSet &indexSet () const
    {
      return impl().indexSet();
    }
 
    int size ( int codim ) const
    {
      return impl().size( codim );
    }
 
    int size ( const GeometryType &type ) const
    {
      return impl().size( type );
    }
 
    bool isConforming () const
    {
      // if implementation provides a method isConforming, call it
      if constexpr ( CheckIsConformingImpl< Implementation >::type::value )
      {
        return impl().isConforming();
      }
      else
      {
        // otherwise default to static conforming flag
        return this->isConformingDefaultImplementation();
      }
    }
 
    template<class EntityType>
    bool contains (const EntityType& e) const
    {
      return impl().indexSet().contains(e);
    }
 
    template< int cd >
    typename Codim< cd > :: Iterator begin () const
    {
      return impl().template begin<cd>();
    }
 
    template< int cd >
    typename Codim< cd > :: Iterator end () const
    {
      return impl().template end<cd>();
    }
 
    template< int cd , PartitionIteratorType pitype >
    typename Codim< cd > :: template Partition< pitype > :: Iterator
    begin () const
    {
      return impl().template begin<cd,pitype>();
    }
 
    template< int cd, PartitionIteratorType pitype >
    typename Codim< cd > :: template Partition< pitype > :: Iterator
    end () const
    {
      return impl().template end<cd,pitype>();
    }
 
    IntersectionIterator
    ibegin ( const typename Codim< 0 > :: Entity &entity ) const
    {
      return impl().ibegin(entity);
    }
 
    IntersectionIterator
    iend ( const typename Codim< 0 > :: Entity &entity ) const
    {
      return impl().iend(entity);
    }
 
    const Communication &comm () const
    {
      return impl().comm();
    }
 
    int overlapSize(int codim) const
    {
      return impl().overlapSize(codim);
    }
 
    int ghostSize(int codim) const
    {
      return impl().ghostSize(codim);
    }
 
    template< class DataHandleImp, class DataType >
    auto communicate ( CommDataHandleIF< DataHandleImp, DataType > &data,
                       InterfaceType iftype,
                       CommunicationDirection dir ) const
    {
      typedef decltype( impl().communicate(data,iftype,dir) ) CommFuture;
      return communicate( data,iftype, dir,
            std::integral_constant< bool, std::is_same< CommFuture, void > :: value >() );
    }
 
    Implementation &impl () { return impl_; }
 
    const Implementation &impl () const { return impl_; }
 
  protected:
    template< class DataHandleImp, class DataType >
    auto communicate ( CommDataHandleIF< DataHandleImp, DataType > &data,
                       InterfaceType iftype,
                       CommunicationDirection dir, std::integral_constant< bool, false > ) const
    {
      return impl().communicate(data,iftype,dir);
    }
 
    struct DeprecatedMethodEmptyFuture : public Future<void>
    {
      void printMessage() const
      {
        std::cerr << "WARNING: GridView::communicate of '" <<
          typeid( Implementation ).name() << "' still returns void. Please update implementation to new interface returning a future object!" << std::endl;
      }
 
      bool ready () {
        printMessage();
        return true;
      }
      void wait () { printMessage(); }
      bool valid () const { printMessage(); return true; }
    };
 
    template< class DataHandleImp, class DataType >
    auto communicate ( CommDataHandleIF< DataHandleImp, DataType > &data,
                       InterfaceType iftype,
                       CommunicationDirection dir, std::integral_constant< bool, true > ) const
    {
      impl().communicate(data,iftype,dir);
      return DeprecatedMethodEmptyFuture();
    }
 
    template <class M>
    class CheckIsConformingImpl
    {
      // check for 'bool isConforming () const'
      template <class T, class R> static std::true_type testSignature(R (T::*)() const);
 
      template <class T>
      static decltype(testSignature(&T::isConforming)) test(std::nullptr_t);
 
      template <class T>
      static std::false_type test(...);
 
    public:
      using type = decltype(test<M>(nullptr));
    };
 
    [[deprecated("GridView implementation is missing a method 'bool isConforming() const'")]]
    bool isConformingDefaultImplementation() const { return bool(conforming); }
 
    Implementation impl_;
  };
 
} // namespace Dune
 
#endif // #ifndef DUNE_GRID_COMMON_GRIDVIEW_HH