Assuming I have a OpenCL driver / environment in which the function clGetPlatformIDs() returns more than one cl_platform_id:

Is it possible to create a create a context including devices from different platforms?

I tried to find an answer in the OpenCL specifications but didn't found any definitive answer. There are some passage in section 4.3 which makes me think it is not possible but I'd like to be sure on this one.