Index: Lib/collections/abc.py
===================================================================
--- Lib/collections/abc.py	(revision 88640)
+++ Lib/collections/abc.py	(working copy)
@@ -46,6 +46,8 @@
 
 class Hashable(metaclass=ABCMeta):
 
+    __slots__ = ()
+
     @abstractmethod
     def __hash__(self):
         return 0
@@ -63,6 +65,8 @@
 
 class Iterable(metaclass=ABCMeta):
 
+    __slots__ = ()
+
     @abstractmethod
     def __iter__(self):
         while False:
@@ -78,6 +82,8 @@
 
 class Iterator(Iterable):
 
+    __slots__ = ()
+
     @abstractmethod
     def __next__(self):
         raise StopIteration
@@ -109,6 +115,8 @@
 
 class Sized(metaclass=ABCMeta):
 
+    __slots__ = ()
+
     @abstractmethod
     def __len__(self):
         return 0
@@ -123,6 +131,8 @@
 
 class Container(metaclass=ABCMeta):
 
+    __slots__ = ()
+
     @abstractmethod
     def __contains__(self, x):
         return False
@@ -137,6 +147,8 @@
 
 class Callable(metaclass=ABCMeta):
 
+    __slots__ = ()
+
     @abstractmethod
     def __call__(self, *args, **kwds):
         return False
@@ -164,6 +176,8 @@
     then the other operations will automatically follow suit.
     """
 
+    __slots__ = ()
+
     def __le__(self, other):
         if not isinstance(other, Set):
             return NotImplemented
@@ -275,6 +289,8 @@
 
 class MutableSet(Set):
 
+    __slots__ = ()
+
     @abstractmethod
     def add(self, value):
         """Add an element."""
@@ -348,6 +364,8 @@
 
 class Mapping(Sized, Iterable, Container):
 
+    __slots__ = ()
+
     @abstractmethod
     def __getitem__(self, key):
         raise KeyError
@@ -451,6 +469,8 @@
 
 class MutableMapping(Mapping):
 
+    __slots__ = ()
+
     @abstractmethod
     def __setitem__(self, key, value):
         raise KeyError
@@ -530,6 +550,8 @@
     __getitem__, and __len__.
     """
 
+    __slots__ = ()
+
     @abstractmethod
     def __getitem__(self, index):
         raise IndexError
@@ -575,12 +597,16 @@
     XXX Should add all their methods.
     """
 
+    __slots__ = ()
+
 ByteString.register(bytes)
 ByteString.register(bytearray)
 
 
 class MutableSequence(Sequence):
 
+    __slots__ = ()
+
     @abstractmethod
     def __setitem__(self, index, value):
         raise IndexError