pythonのsetup.pyにswigでC++のオプションを付けるの術

from distutils.core import setup, Extension

setup(
ext_modules = [
Extension('_example', ['example.i', 'example.cxx', 'sample.cxx'],
library_dirs=[],
libraries=[],
extra_compile_args=[],
extra_link_args=[],
swig_opts=["-c++"],)
])