macro(subdirlist result curdir)
  file(GLOB children RELATIVE ${curdir} ${curdir}/*)
  set(dirlist "")
  foreach(child ${children})
      if(IS_DIRECTORY ${curdir}/${child})
        set(dirlist ${dirlist} ${child})
    endif()
  endforeach()
  set(${result} ${dirlist})
endmacro()
subdirlist(SUBDIRS ${CMAKE_CURRENT_SOURCE_DIR})
foreach(subdir ${SUBDIRS})
    add_subdirectory(${subdir})
endforeach()