[Dune-devel] getting the first element

[Agnese, Marco]

The "range based for" are not new iterators but simply a feature of C++11 which allows you to loop over a container in the range begin() and end(). Therefore you need a begin() and end() iterator for ever container you want to loop over. The class elements wrap the iterators in such a way that can be used by the range based for.

Obviously, if you want to loop over all the leaf grid view I would use the new syntax but if you need to extract a single elements or to loop over a subset I would explicitly extract the needed iterators.
HIH

Cheers,
Marco


________________________________________
From: Aleksejs Fomins <aleksejs.fomins at lspr.ch>
Sent: 01 December 2015 17:06
To: Agnese, Marco; dune-devel at dune-project.org
Subject: Re: [Dune-devel] getting the first element

Hey Marco,

By new iterators I meant

for (auto&& element : elements(gv)) {}

I was not sure that the thing you just suggested was still allowed. I will try

Thanks.

Aleksejs


On 01.12.2015 17:58, Agnese, Marco wrote:
> Something like this
>
> const auto firstEntity(*(gv.template begin<0>()));
>
> ??
>
> I don't understand what you mean with new iterators...
> ________________________________________
> From: dune-devel-bounces+m.agnese13=imperial.ac.uk at dune-project.org <dune-devel-bounces+m.agnese13=imperial.ac.uk at dune-project.org> on behalf of Aleksejs Fomins <aleksejs.fomins at lspr.ch>
> Sent: 01 December 2015 16:43
> To: dune-devel at dune-project.org
> Subject: [Dune-devel] getting the first element
>
> Dear Dune,
>
> Another small question.
>
> I want to extract 1 element from the leafGridView. I don't care which one it is.
> How do I do this with the new fancy iterators?
>
> Best,
> Aleksejs
>
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