[CMake] unset() command

[Brad King]

Philip Lowman wrote:
> On Thu, Aug 21, 2008 at 9:01 AM, Brad King <brad.king at kitware.com
> <mailto:brad.king at kitware.com>> wrote:
>     However, this:
> 
>      unset(MY_CACHE_VARIABLE)
> 
>     should not remove the cache entry.  It should only unset the CMake
>     variable.  In order to remove the cache entry, we should require
> 
>      unset(MY_CACHE_VARIABLE CACHE)
> 
>     Otherwise there is no way to remove the variable without removing the
>     cache entry.
> 
>     One nice thing about the unset command is that it doesn't make sense to
>     provide a value.  Therefore we can add extra arguments like 'CACHE'
>     without ambiguity.
> 
> 
> That makes sense.  Would you like me to fix the patch and resubmit?

Yes.  Please include this information in the documentation of the command.

Thanks,
-Brad