def __init__(cls, *args, **kw):
BasicMeta.__init__(cls, *args, **kw)
# we are going to inject singletonic __new__, here it is:
def cls_new(cls):
try:
obj = getattr(SingletonFactory, cls.__name__)
except AttributeError:
obj = Basic.__new__(cls, *(), **{})
setattr(SingletonFactory, cls.__name__, obj)
return obj
cls_new.__name__ = '%s.__new__' % (cls.__name__)
assert not cls.__dict__.has_key('__new__'), \
'Singleton classes are not allowed to redefine __new__'
# inject singletonic __new__
cls.__new__ = staticmethod(cls_new)
# Inject pickling support.
def cls_getnewargs(self):
return ()
cls_getnewargs.__name__ = '%s.__getnewargs__' % cls.__name__
assert not cls.__dict__.has_key('__getnewargs__'), \
'Singleton classes are not allowed to redefine __getnewargs__'
cls.__getnewargs__ = cls_getnewargs
# tag the class appropriately (so we could verify it later when doing
# S.<something>
cls.is_Singleton = True
