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

[E. Rosten]

On Wed, 13 Jan 2010, Gerhard Reitmayr wrote:

> > By the way, this would of course mean there will be an extra if in each 
> > assignment from vectors or operators.
>
> ok, I understand that. but there is one already for the size mismatch I assume ?

Yes, but it is swithed off if you compile with NDEBUG or TOON_NDEBUG.

> > I implemented such a system for Vector<Resizable> which I subsequently removed.
> >
> > cvs up -D 20090926
> >
> > should get you there. Each allocator implements a try_resize() member. This may do 
> > nothing (for static and Dynamic), or it may do something 9for Resizable). This member 
> > is called at the beginning of operator=. Then the size checks occur. This system 
> > could be reinstated so that try_resize works first time on Vector<Dynamic> and 
> > is a noop all other times.
> >
> >
> > However, STL vector can call operator=
>
> that is true... in this case the Dynamic solution doesn't make sense. 
> Probably forget it and make Resizable assignable, then that should be 
> used. that looks like the best solution to me right now :/

One other hack is available, and it is quite nasty. That is to make 
Vector<Resizable> only resize automatically when it is assigned from 
another Vector<Resizable>. That would make it work in STL containers 
safely, but it would otherwise behave in the normal manner.

This would introduce rather unpleasantly inconsistent bahaviour for 
Vector<Resizable>, but have the benefit of having Vector<Resizable> behave 
more like Vector<Dynamic>.

Personally, I prefer making Vector<Resizable> behave like a fully-featured 
resizable vector with resize on assignment working everywhere.

Comments?

-Ed