[plt-scheme] adding C++ code under OS X

>Greetings,
>
>Does anyone have a small example showing how to add C++ code to 
>DrScheme.  Ideally as an XCode project.
>
>Thanks,
>
>Kaveh
>
>Kaveh Kardan                 Chief Technologist
>kaveh at hawaii.edu             Academy for Creative Media
>(808)956-5302                University of Hawaii
>

If you only want to call simple C from Scheme, the "Foreign-Function 
Interface to C" (in MZC) is enough. 

The "Inside PLT MzScheme" describes the full MzScheme's C interface. 
Although it is called "C" interface, C++ codes are also acceptable. 

The plt/collects/mzscheme/examples directory in the PLT distribution 
contains some examples. The tree example is a about C++ class.