On Wed, Sep 17, 2003 at 10:36:08AM +0100, Angus Leeming wrote:
> Andre Poenitz wrote:
> > It is not legal to instantiate a template on an incomplete type,
> > i.e. this
> >
> > #ifndef PARAGRAPH_LIST_FWD_H
> > #define PARAGRAPH_LIST_FWD_H
> >
> > #include <list>
> > #include <utility>
> >
> > class Paragraph;
> >
> > typedef std::list<Paragraph> ParagraphList;
> >
> > typedef std::pair<ParagraphList::iterator, int> PitPosPair;
> >
> > #endif
> >
> > is bad.
> >
> > Andre'
>
> And where, exactly, is the instantiation?
Good point.
I have a bad feeling nevertheless, but I'll go ask the gurus as I don't
find something explicitly forbidding it.
> I see none... Moreover, you'll find that any place ParagraphList is
> actually instantiated (in the .C files) there is a #include
> "paragraph.h" as well as a #include "ParagraphList_fwd.h".
But it doesn't work with 'class Paragraph;' removed. So this means usage
is something like
#include <list>
class Paragraph;
typedef std::list<Paragraph> ParagraphList;
class Paragraph {
...
};
Well, I go and ask.
Andre'
--
Those who desire to give up Freedom in order to gain Security, will not have,
nor do they deserve, either one. (T. Jefferson or B. Franklin or both...)
