[Dune] Communicating IdSet elements

[Markus Blatt]

Hi,

On Tue, Jul 26, 2011 at 01:31:51PM +0200, Jö Fahlke wrote:
> With ALUGrid the is a small pitfall however: alugrid provides two
> loadBalance(dataHandle) methods, one for Dune-datahandles, and one for
> ALUGrid-native datahandles.  These two datahandles have a somewhat different
> interface.  The methods are declared like
> 
>   // ALU-specific datahandle
>   template<class DataHandle>
>   bool loadBalance(DataHandle &data);
> 
>   // Dune datahandle
>   template<class DataHandleImpl, class Data>
>   bool loadBalance(CommDataHandleIF<DataHandleImpl, Data> &dataHandle);
> 
> This means that if you have a Dune data handle like
> 
>   template<class Grid>
>   class RedistributeDataHandle :
>     public Dune::CommDataHandleIF<RedistributeDataHandle<Grid>, int>
>   { ... };
> 
> you need to cast it to it's base class when calling loadBalance():
> 
>   typedef RedistributeDataHandle<Grid> DataHandle;
>   DataHandle dh(*gridp, elementTagMap);
>   gridp->loadBalance(static_cast<Dune::CommDataHandleIF<DataHandle, int>&>(dh));
> 
> Otherwise the compiler will assume it is an ALU-specific datahandle and will
> probably complain.  See
> <https://svn.dune-project.org/svn/dune-grid/trunk/src/gmsh-to-alu/main.hh> for

Maybe we should incorpoprate this into the FAQ?

Markus
-- 
Markus Blatt, Interdisciplinary Center for Scientific Computing,
University Heidelberg, Im Neuenheimer Feld 368, D-69120 Heidelberg
Tel: +49 (0) 6221 548881 Fax: +49 (0) 6221 548884

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