Why not?

If you own the sources, and if you don't want to hide any of the symbols - simply include the whole stuff. Yeah, include. You might as well concatenate the two sources together if you want, using copy or similar primitive command line tool.

I know this does not sound too scientific, but realize, that the (almost) only reason why the "interface" and "implementation" split is made is because software vendors want to sell libraries as binaries without providing the actual sources. Other uses are hiding of the "private" symbols from the "includer" and shortening the compilation time by not having to recompile a module which has not been touched, but none of these are relevant here.

That the header files provide a certain way of "documentation" of an API I leave without comment.

Jan Waclawek