Re: [Toon-members] Re: STL containers with TooN

[Gerhard Reitmayr]

some thoughts...

On 11 Jan 2010, at 16:09, E. Rosten wrote:

> On Mon, 11 Jan 2010, Gabriel Nützi wrote:
> 
>> Solved!!
>> Sorry, I was stupid!
> 
> Really?
> 
> Actually, this is a problem in TooN. Vector<Dynamic> and Vector<Resizable> 
> are copy constructible, but operator= will only work if the vectors are 
> already the same size. Vector<Dyanmic> is not default constructible, but 
> Vector<Resizable> is.
> 
> I don't know what the precise requirements of the STL are. I think making 
> Vector<Resizable> resize automatically on a call to operator= will make it 
> completely safe to store in all STL containers.
> 

just from reading docs, one needs default, copy constructors and assignment to 
work. that makes sense for example with the following code:

vector<Vector<Dynamic> > v(10); // 10 dynamic vectors
v[0] = Vector<Dynamic>(10);     // set first to a vector with 10 els
v[1] = Vector<Dynamic>(20);     // set second to a vector with 20 els

Resizable makes sense, i guess that assignment on a Resizable should always 
work (and resize as necessary)

For Dynamic, how about making it stateful and have the default constructor set 
a sentinel that allows it to be resized with the first assignment ? (and 
assert, if it is assigned from another Dynamic in the same state )? a copy 
constructor or explicit size constructor will not allow further resizing, 
similarly after the first resize. that way the code above would work and one 
would still have the same runtime safety...

cheers,
  Gerhard

> Thoughts, anyone?
> 
> -Ed
> 
> 
> 
>> Thanks!
>> 
>> Am 10.01.2010 um 21:37 schrieb Gabriel Nützi:
>> 
>>> Hello again
>>> Sorry for my questions, but I am using TooN permanently, with all its 
>>> advantages... (LU,SymEigen....)
>>> I was wondering, because I need a container which is as fallowing
>>> list < Vector<Dynamic,double> >   myList;
>>> Why does it give RunTime problems and segmentation errors when I try to use 
>>> the list by inserting and deleting Vectors, it happens also when the Vector 
>>> is not dynamic ...
>>> Is there any troubles with the containers and TooN?
>>> This crashed in Runtime:
>>> //===================================
>>> list < Vector<Dynamic,double> >   myList;
>>> myList.push_back( makeVector (1,1,1) );
>>> myList.push_back( makeVector (2,1,1) );
>>> myList.push_back( makeVector (3,1,1) );
>>> list < Vector<Dynamic,double> > ::iterator it;
>>> it = myList.begin();
>>> it++;
>>> myList.erase(it);
>>> //=================================
>>> Thanks a lot
>>> Gabriel!
>> 
>> 
>> 
>> _______________________________________________
>> Toon-members mailing list
>> address@hidden
>> http://lists.nongnu.org/mailman/listinfo/toon-members
> 
> -- 
> (You can't go wrong with psycho-rats.)(http://mi.eng.cam.ac.uk/~er258)
> 
> /d{def}def/f{/Times s selectfont}d/s{11}d/r{roll}d f 2/m{moveto}d -1
> r 230 350 m 0 1 179{ 1 index show 88 rotate 4 mul 0 rmoveto}for/s 12
>    d f pop 235 420 translate 0 0 moveto 1 2 scale show 
> showpage_______________________________________________
> Toon-members mailing list
> address@hidden
> http://lists.nongnu.org/mailman/listinfo/toon-members

--
Gerhard Reitmayr
Institute for Computer Graphics and Vision
http://www.icg.tugraz.at/Members/gerhard
tel: ++43 316 873 5082