message: COMP: Set RTK target properties
  When building RTK against an ITK build tree, CMAKE_CXX_STANDARD is required
  to add gcc -std=c++11 flag.
diff: @@ -19,6 +19,17 @@ foreach(p ${CMAKE_POLICIES})
  endif()
  endforeach()
  +## Set the default target properties for RTK
  +if(NOT CMAKE_CXX_STANDARD)
  + set(CMAKE_CXX_STANDARD 11) # Supported values are ``11``, ``14``, and ``17``.
  +endif()
  +if(NOT CMAKE_CXX_STANDARD_REQUIRED)
  + set(CMAKE_CXX_STANDARD_REQUIRED ON)
  +endif()
  +if(NOT CMAKE_CXX_EXTENSIONS)
  + set(CMAKE_CXX_EXTENSIONS OFF)
  +endif()
  +
  #=========================================================
  # Help function to debug CMake
  macro (DD in)
  