[CMake] INCLUDE_DIRECTORIES empty?

[David Doria]

> This is a read-only directory property:
>
> http://www.cmake.org/cmake/help/cmake-2-8-docs.html#prop_dir:INCLUDE_DIRECTORIES
>
> Michael

That's ok, all I want to do is read it. That's why I thought it would just be:

MESSAGE("INCLUDE_DIRECTORIES: ${INCLUDE_DIRECTORIES}")

But I guess INCLUDE_DIRECTORIES is a function, not a variable? Which
variable gets set when you call the INCLUDE_DIRECTORIES function then?

Thanks,

David