[Dune] Interface addition

[Carsten Gräser]

Am 03.12.2010 11:57, schrieb Markus Blatt:
> Hi,
> 
> On Thu, Dec 02, 2010 at 11:39:31PM +0100, Carsten Gräser wrote:
>> I'd like to add helper template ExtendedTuple to prepend or append a type
>> to a tuple to tupleutility.hh. It provides the types:
>>
>> ExtendedTuple<tuple<T1,...,TN>,T>::prepended  ==  tuple<T,T1,...,TN>
>> ExtendedTuple<tuple<T1,...,TN>,T>::appended   ==  tuple<T1,...,TN,T>
>>
> 
> Generally, yes.
> I would prefer two distinct objects for the task to improve compile
> time.
That's a good point.

> Further more, you might want to adhere to the boost::fusion naming
> convention (push_back, push_front). This will save you a lot of time
I assumed that there must be something similar in MLP or fusion,
but didn't find it myself. Although push_back, and push_front
in fusion work a little different since they do not export a
simple tuple these name would also be fine.

In view of the discussion on the meeting it should perhaps be named
PushBack<foo, T>::type and PushFront<foo, T>::type.

> when C++2x incorporates fusion and you fellow developers, start
> requesting to move to the new standard. ;)
No need to wait for fusion in c++2x.

If the promised time arrives where c++0x is an official standard that
is implemented by each and every compiler on every cluster you could imagine,
then we could even remove the template and use the following simple snippet
directly in the application

template<class... Args, class T>
struct PushBack<typename std::tuple<Args...>, T>
{
  typedef typename std::tuple<Args...,T> type;
};
template<> struct PushBack<> {};

Best,
Carsten


> BTW: You missed the patch and appended the whole file.
Ups - I sent the wrong file.

-- 
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Carsten Gräser           | phone: +49-30 / 838-75349
Freie Universität Berlin | fax  : +49-30 / 838-54977
Institut für Mathematik  | email: graeser at math.fu-berlin.de
Arnimallee 6             |
14195 Berlin, Germany    | URL  : http://page.mi.fu-berlin.de/graeser
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