#include <entitypointer.hh>
Template parameters are:
GridImp
Type that is a model of Dune::GridIteratorImp
Class template that is a model of Dune::EntityPointer
The EntityPointer class template wraps an object of type IteratorImp and forwards all member function calls to corresponding members of this class. In that sense EntityPointer defines the interface and IteratorImp supplies the implementation.
The EntityPointer can be used like a static iterator. It points to a Dune::Entity and can be dereferenced, compared and it knows the Entity's level.
You should be able to initialize and interpret every Dune::XxxIterator that iterates over entities as a Dune::EntityPointer. Therefore we need an inheritance hierarchy of the Iterator wrappers:
class Dune::EntityPointer<...>; class Dune::LevelIterator<...> : public Dune::EntityPointer<...>; class Dune::HierarchicIterator<...> : public Dune::EntityPointer<...>; class Dune::LeafIterator<...> : public Dune::EntityPointer<...>;
This hierarchy must be mimicked in the implementation (i.e. SGrid):
class SEntityPointer<...> : public Dune::EntityPointerDefault<..., SEntityPointer>; class SLevelIterator<...> : public SEntityPointer <...>, public Dune::LevelIteratorDefault <..., SLevelIterator>; class SHierarchicIterator<...> : public SEntityPointer <...>, public Dune::HierarchicIteratorDefault <..., SHierarchicIterator>; ...
This leads to a hierarchy where Dune::LevelIterator<..., SLevelIterator> inherits Dune::EntityPointer<..., SLevelIterator> and Dune::HierarchicIterator<..., SHierarchicIterator> inherits Dune::EntityPointer<..., SHierarchicIterator>. And virtualy all Dune::EntityPointer<..., SXxxIterator> are descendents of Dune::EntityPointer<..., SEntityPointer>.
Now you can compare Dune::LevelIterator with Dune::EntityPointer and Dune::LeafIterator with Dune::HierarchicIterator. And you can assign Dune::EntityPointer from any Dune::XxxIterator class. Even more, you can cast an Iterator refence to a reference pointing to Dune::EntityPointer.
The compiler takes care that you only assign/compare Iterators from the same Grid.
The downside (or advantage) of this inheritance is that you can not use different comparison operators and different dereference oprators for the different Iterators in one Grid. On the first sight it is a downside because one might consider it a good idea to have special treatment for different iterators. On the other hand it's very confusing for the user if different Iterators show different behavior in the same situation. So now they are forced to show the same behavior.
Public Types | |
enum | |
codimension of entity pointer | |
enum | { codim = IteratorImp::codimension } |
typedef IteratorImp | ImplementationType |
type of real implementation | |
typedef IteratorImp::Entity | Entity |
The Entity that this EntityPointer can point to. | |
Public Member Functions | |
Constructor & conversion | |
template<class ItImp> | |
EntityPointer (const EntityPointer< GridImp, ItImp > &ep) | |
Templatized copy constructor from arbitrary IteratorImp. This enables that an EntityPointer can be copy-constructed from LevelIterator, LeafIterator and HierarchicIterator (because these are derived from EntityPointer<...> with their corresponding implementation. | |
EntityPointer (const Entity &entity) | |
Templatized constructor from type of entity that this entity pointer points to. This constructor can be used to create an entity pointer from an entity in order to store an entity. The implementation of EntityPointer has to have a constructor taking a Dune::Entity. | |
operator EntityPointer< GridImp, base > & () | |
Cast to EntityPointer with base class of implementation as engine. This conversion ensures assignablity of LevelIterator, LeafIterator and HierarchicIterator to EntityPointer. | |
operator const EntityPointer< GridImp, base > & () const | |
Cast to EntityPointer with const base class of implementation as engine. This conversion ensures assignablity of LevelIterator, LeafIterator and HierarchicIterator to EntityPointer. | |
void | compactify () |
Reduce the entity pointers used memory to a minimum necessary to store all needed information. | |
Dereferencing | |
Entity & | operator* () const |
Dereferencing operator. | |
Entity * | operator-> () const |
Pointer operator. | |
Compare methods | |
bool | operator== (const EntityPointer< GridImp, base > &rhs) const |
Checks for equality. Only works for EntityPointers and iterators on the same grid. Due to the conversion operators one can compare all kinds of iterators and EntityPointer. | |
bool | operator!= (const EntityPointer< GridImp, base > &rhs) const |
Checks for inequality. Only works for EntityPointers and iterators on the same grid. Due to the conversion operators one can compare all kinds of iterators and EntityPointer. | |
Query methods | |
int | level () const |
Ask for level of entity. This method is redundant and is only there for efficiency reasons. It allows an implementation to return the level without actually constructing the entity. | |
Implementor interface | |
EntityPointer (const IteratorImp &i) | |
Copy Constructor from an Iterator implementation. | |
bool | equals (const EntityPointer &rhs) const |
Forward equality check to realIterator. | |
Protected Types | |
typedef Dune::EnableIfInterOperable < typename IteratorImp::EntityPointerImp, IteratorImp, typename IteratorImp::EntityPointerImp > ::type | base |
autocheck wether imp is convertable into imp::base | |
Protected Member Functions | |
ImplementationType & | getRealImp () |
return reference to the real implementation | |
const ImplementationType & | getRealImp () const |
return reference to the real implementation |
anonymous enum |
codim | The codimension of this EntityPointer. |
Dune::EntityPointer< GridImp, IteratorImp >::EntityPointer | ( | const IteratorImp & | i | ) | [inline] |
Copy Constructor from an Iterator implementation.
You can supply LeafIterator, LevelIterator, HierarchicIterator or EntityPointer.