Re: [eigen] An insistent plea for an input operator

[Helmut Jarausch <jarausch@xxxxxxxxxxxxxxxxxxx>]

On 07/20/10 16:06:48, Hauke Heibel wrote:
> I am not a big fan of this mainly due to safety reasons and
> consistency reasons.
> 
> Currently, you can even use an ifstream since it is an istream. We
> also need to deal with the way in which the data is given. Why should
> it be given as 1 2 3 4 ... and not 1,2,3,4 (probably because of the
> locale, see my next point).

But that's the standard way of separating data item in an istream.

I one doesn't like it one has to write one's own stream derived from 
streambuf.

> Also, I am not sure how this is going to work with floats on 
> different
> locals.  Some systems have '.' as their decimal separator and others
> ','. You don't recognize this when working in C++ but I think you
> will, when you start processing user input.
> 
> For me, the inclusion of such an operator must at least be optional,
> i.e. not automatically through Dense, Core or Eigen. If it were in 
> the
> Eigen namespace, how would I provide my own version? Does it have to
> go to another namespace?
> 




-- 
Helmut Jarausch

Lehrstuhl fuer Numerische Mathematik
RWTH - Aachen University
D 52056 Aachen, Germany