[CMake] Add configuration support to include_directories()

[Bill Hoffman]

Robert Dailey wrote:

> For debug: C:\foo\bar-d
> For release: C:\foo\bar
> 
> Note that the text "Debug" or "Release" is not used in the include path, 
> so simply using CFG_INTDIR would not work I don't think (Unless I'm 
> missing something again). This is why in CMake I need to do something 
> like this:
> 
> if( debug )
>     include_directories( C:\foo\bar-d )
> else()
>     include_directories( C:\foo\bar )
> endif()
> 
> Thanks again to everyone for their continued help.
> 

OK, well, since VS supports multiple configurations at VS time, and not 
CMake time, it is impossible to have the above if statement.   There is 
just no way to know what configuration the user will pick.   The user 
gets to pick a long time after that if statement was executed by CMake. 
  So, I think you are sort of out of luck right now...   What CMake 
needs is per configuration include_directories for this to work.   One 
thing that might work as a work around, is that you could copy the 
header file via a custom command into your build tree, and then use the 
CFG_INTDIR approach.

-Bill