"Jonathan Wakely" <cow@compsoc.man.ac.uk> wrote in message news:20050323180511.GA54619@compsoc.man.ac.uk... | On Wed, Mar 23, 2005 at 06:15:14PM +0100, Thorsten Ottosen wrote: | | > "Jonathan Wakely" <cow@compsoc.man.ac.uk> wrote in message | > news:20050323165335.GA52151@compsoc.man.ac.uk... | > | On Wed, Mar 23, 2005 at 04:06:09PM +0000, Joaquin M Lopez Munoz wrote: | > | | > | > "I can't think of any way that this extension could | > | > break a conforming program, considering that users | > | > are not permitted to forward-declare standard | > | > library components" | > | > | > | > Is this really so? Why cannot I forward declare a | > | > stdlib component? | > | | > | Opening namespace std for anything except specialisations of standard | > | library templates (with user-defined types as parameters) is illegal. | > | > yes, but why? | | Because the Standard says so! :-) yes, I know that...I was interesting in examples of *how* we can break programs with forward declarations. -Thorsten