[CMake] Function for visibility definitions

[Bill Hoffman]

Hilton Medeiros wrote:
> Wow, now you got me.
> That is why I love discussions.
> Thanks for your insight, now I (my hard-as-rock head) can understand
> why this is not feasible.
> 
> As a side note I think this should be in a list, maybe in the wiki, to
> advise others no to do this. A list of 'do not even think about this'.
> 
> I'm sorry for the incovenient.
> 
> Kind regards,
> Hilton
> 
> On Thu, 11 Feb 2010 02:26:27 -0500
> Mike Jackson <mike.jackson at bluequartz.net> wrote:
> 
>> And what happens when a project wants to use my library? That
>> project must now use Cmake and your macro. What if a project
>> downstream can not use Cmake to define those macros? What then?
>>

That said, you could have CMake configure a .h file that had this stuff 
in it.  It might be nice if the function did that automatically, as it 
is almost the same code for every project.  Then once your project was 
built with CMake, you would install the configured .h files and other 
build systems could still use the software.

-Bill