Re: Introduce a Grob_interface class (issue 251700043 by address@hidden)

[Dan Eble]

> On Apr 30, 2016, at 05:37 , address@hidden wrote:
> 
> Ok, I need a refresher here.  What was the ultimate aim of this
> patch/issue?  As it stands, actual interface classes like
> Axis_group_interface don't have _any_ connection to a type any more.
> Instead, there is a Grob_interface template class depending on them with
> an arbitrarily named single instance not used for anything but
> initialization.

I’m sorry I can’t give much of a refresher.  I’ve been busy on unrelated 
projects for months.

This comment:

> T::has_interface (grob) has become has_interface<T> (grob).  (Like unsmob<T>, 
> it has the advantage of not being inherited by derived classes of T.)

... reminds me--if I recall correctly, which might not be the case--that a 
trigger for this patch was the belief that if one called 
Derived::has_interface(grob) and had neglected to implement has_interface() for 
the derived class, the question would be answered by the nearest base 
implementation, and that would be the wrong answer to the question.

This patch was at least an attempt to disarm that booby trap.  It would also 
have fixed any such mistakes that were present, but I can’t remember if there 
were any.

If it hampers your greater clean-up, throw it away.

Regards,
— 
Dan