[CMake] How to create SOURCE_GROUP for include files

[Steve Johns]

Hi.

What I would like to accomplish:

In the MS VC7.1 .Net IDE

In the Solution Explorer, inside my project's folder, at the same level as 
the 'Source Files' folder, I would like to create a 2nd folder 'Include 
Files' that would contain/display the ".hpp" files for my project.

My source tree is just a simple setup with './src' and './incl' directories 
containing the ".cpp" and ".hpp" files respectively.

__

I must be misunderstanding something fundamental about the SOURCE_GROUP() 
command, or what is necessary for it to work, because despite trying every 
variation of:

SOURCE_FILES( "Include Files" FILES  afile.hpp bfile.hpp )

that I can conceive of typing, absolutely nothing happens, and no 'Include 
Files' appears in the IDE.