seek = interp2app(W_IOBase.seek_w),
    tell = interp2app(W_IOBase.tell_w),
    truncate = interp2app(W_IOBase.truncate_w),
    fileno = interp2app(W_IOBase.fileno_w),
    isatty = interp2app(W_IOBase.isatty_w),
    readable = interp2app(W_IOBase.readable_w),
    writable = interp2app(W_IOBase.writable_w),
    seekable = interp2app(W_IOBase.seekable_w),

    _checkReadable = interp2app(check_readable_w),
    _checkWritable = interp2app(check_writable_w),
    _checkSeekable = interp2app(check_seekable_w),
    _checkClosed = interp2app(W_IOBase.check_closed_w),
    closed = GetSetProperty(W_IOBase.closed_get_w),
    __dict__ = GetSetProperty(descr_get_dict, descr_set_dict, cls=W_IOBase),
    __weakref__ = make_weakref_descr(W_IOBase),

    readline = interp2app(W_IOBase.readline_w),
    readlines = interp2app(W_IOBase.readlines_w),
    writelines = interp2app(W_IOBase.writelines_w),
)

class W_RawIOBase(W_IOBase):
    # ________________________________________________________________
    # Abstract read methods, based on readinto()

    def read_w(self, space, w_size=None):
        size = convert_size(space, w_size)
        if size < 0:
            return space.call_method(self, "readall")

W_CData.typedef = TypeDef(
    '_cffi_backend.CData',
    __module__ = '_cffi_backend',
    __name__ = '<cdata>',
    __repr__ = interp2app(W_CData.repr),
    __bool__ = interp2app(W_CData.bool),
    __int__ = interp2app(W_CData.int),
    __long__ = interp2app(W_CData.long),
    __float__ = interp2app(W_CData.float),
    __len__ = interp2app(W_CData.len),
    __lt__ = interp2app(W_CData.lt),
    __le__ = interp2app(W_CData.le),
    __eq__ = interp2app(W_CData.eq),
    __ne__ = interp2app(W_CData.ne),
    __gt__ = interp2app(W_CData.gt),
    __ge__ = interp2app(W_CData.ge),
    __hash__ = interp2app(W_CData.hash),
    __getitem__ = interp2app(W_CData.getitem),
    __setitem__ = interp2app(W_CData.setitem),
    __add__ = interp2app(W_CData.add),
    __radd__ = interp2app(W_CData.add),
    __sub__ = interp2app(W_CData.sub),
    __getattr__ = interp2app(W_CData.getattr),
    __setattr__ = interp2app(W_CData.setattr),
    __call__ = interp2app(W_CData.call),
    __iter__ = interp2app(W_CData.iter),
    __weakref__ = make_weakref_descr(W_CData),
    )
W_CData.typedef.acceptable_as_base_class = False

                                          W_Root, W_Root]),
    __delslice__ = interp2app(W_InstanceObject.descr_delslice,
                             unwrap_spec=['self', ObjSpace, W_Root, W_Root]),
    __call__ = interp2app(W_InstanceObject.descr_call,
                          unwrap_spec=['self', ObjSpace, Arguments]),
    __nonzero__ = interp2app(W_InstanceObject.descr_nonzero,
                             unwrap_spec=['self', ObjSpace]),
    __cmp__ = interp2app(W_InstanceObject.descr_cmp,
                         unwrap_spec=['self', ObjSpace, W_Root]),
    __hash__ = interp2app(W_InstanceObject.descr_hash,
                          unwrap_spec=['self', ObjSpace]),
    __index__ = interp2app(W_InstanceObject.descr_index,
                           unwrap_spec=['self', ObjSpace]),
    __contains__ = interp2app(W_InstanceObject.descr_contains,
                         unwrap_spec=['self', ObjSpace, W_Root]),
    __pow__ = interp2app(W_InstanceObject.descr_pow,
                         unwrap_spec=['self', ObjSpace, W_Root, W_Root]),
    __rpow__ = interp2app(W_InstanceObject.descr_rpow,
                         unwrap_spec=['self', ObjSpace, W_Root, W_Root]),
    next = interp2app(W_InstanceObject.descr_next,
                      unwrap_spec=['self', ObjSpace]),
    __weakref__ = make_weakref_descr(W_InstanceObject),
    __del__ = interp2app(W_InstanceObject.descr_del,
                         unwrap_spec=['self', ObjSpace]),
    **rawdict
)

class W_InstanceObjectWithDel(W_InstanceObject):
    def __del__(self):
        self._enqueue_for_destruction(self.space)

                              doc = "file mode ('r', 'U', 'w', 'a', "
                                    "possibly with 'b' or '+' added)"),
    encoding = interp_attrproperty('encoding', cls=W_File),
    errors = interp_attrproperty('errors', cls=W_File),
    closed   = GetSetProperty(descr_file_closed, cls=W_File,
                              doc="True if the file is closed"),
    newlines = GetSetProperty(descr_file_newlines, cls=W_File,
                              doc="end-of-line convention used in this file"),
    softspace= GetSetProperty(descr_file_softspace,
                              descr_file_setsoftspace,
                              cls=W_File,
                              doc="Support for 'print'."),
    __repr__ = interp2app(W_File.file__repr__),
    writelines = interp2app(W_File.file_writelines),
    __exit__ = interp2app(W_File.file__exit__),
    __weakref__ = make_weakref_descr(W_File),
    **dict([(name, interp2app(getattr(W_File, 'file_' + name)))
                for name in W_File._exposed_method_names])
    )

# ____________________________________________________________

def wrap_list_of_str(space, lst):
    return space.newlist_bytes(lst)

class FileState:
    def __init__(self, space):
        self.openstreams = {}

def getopenstreams(space):
    return space.fromcache(FileState).openstreams

    def fget_item(self, space):     return self._fget('i')
    def fget_length(self, space):   return self._fget('l')
    def fget_fields(self, space):   return self._fget('f')
    def fget_args(self, space):     return self._fget('a')
    def fget_result(self, space):   return self._fget('r')
    def fget_ellipsis(self, space): return self._fget('E')
    def fget_abi(self, space):      return self._fget('A')
    def fget_elements(self, space): return self._fget('e')
    def fget_relements(self, space):return self._fget('R')


W_CType.typedef = TypeDef(
    'CTypeDescr',
    __module__ = '_cffi_backend',
    __repr__ = interp2app(W_CType.repr),
    __weakref__ = make_weakref_descr(W_CType),
    kind = GetSetProperty(W_CType.fget_kind, doc="kind"),
    cname = GetSetProperty(W_CType.fget_cname, doc="C name"),
    item = GetSetProperty(W_CType.fget_item, doc="pointer to, or array of"),
    length = GetSetProperty(W_CType.fget_length, doc="array length or None"),
    fields = GetSetProperty(W_CType.fget_fields, doc="struct or union fields"),
    args = GetSetProperty(W_CType.fget_args, doc="function argument types"),
    result = GetSetProperty(W_CType.fget_result, doc="function result type"),
    ellipsis = GetSetProperty(W_CType.fget_ellipsis, doc="function has '...'"),
    abi = GetSetProperty(W_CType.fget_abi, doc="function ABI"),
    elements = GetSetProperty(W_CType.fget_elements, doc="enum elements"),
    relements = GetSetProperty(W_CType.fget_relements,
                               doc="enum elements, reversed"),
    __dir__ = interp2app(W_CType.dir),
    )
W_CType.typedef.acceptable_as_base_class = False

Methods of socket objects (keyword arguments not allowed):

accept() -- accept a connection, returning new socket and client address
bind(addr) -- bind the socket to a local address
close() -- close the socket
connect(addr) -- connect the socket to a remote address
connect_ex(addr) -- connect, return an error code instead of an exception
dup() -- return a new socket object identical to the current one [*]
fileno() -- return underlying file descriptor
getpeername() -- return remote address [*]
getsockname() -- return local address
getsockopt(level, optname[, buflen]) -- get socket options
gettimeout() -- return timeout or None
listen(n) -- start listening for incoming connections
makefile([mode, [bufsize]]) -- return a file object for the socket [*]
recv(buflen[, flags]) -- receive data
recvfrom(buflen[, flags]) -- receive data and sender's address
sendall(data[, flags]) -- send all data
send(data[, flags]) -- send data, may not send all of it
sendto(data[, flags], addr) -- send data to a given address
setblocking(0 | 1) -- set or clear the blocking I/O flag
setsockopt(level, optname, value) -- set socket options
settimeout(None | float) -- set or clear the timeout
shutdown(how) -- shut down traffic in one or both directions

 [*] not available on all platforms!""",
    __new__ = descr_socket_new,
    __weakref__ = make_weakref_descr(W_RSocket),
    ** socketmethods
    )

        w_result = space.call_args(w_init, __args__)
        if not space.is_w(w_result, space.w_None):
            raise oefmt(space.w_TypeError, "__init__() should return None")
    elif __args__.arguments_w or __args__.keywords:
        raise oefmt(space.w_TypeError, "this constructor takes no arguments")
    return w_inst

W_ClassObject.typedef = TypeDef("classobj",
    __new__ = interp2app(descr_classobj_new),
    __repr__ = interp2app(W_ClassObject.descr_repr),
    __str__ = interp2app(W_ClassObject.descr_str),
    __call__ = interp2app(class_descr_call),
    __getattribute__ = interp2app(W_ClassObject.descr_getattribute),
    __setattr__ = interp2app(W_ClassObject.descr_setattr),
    __delattr__ = interp2app(W_ClassObject.descr_delattr),
    __weakref__ = make_weakref_descr(W_ClassObject),
)
W_ClassObject.typedef.acceptable_as_base_class = False


def make_unary_instance_method(name):
    def unaryop(self, space):
        w_meth = self.getattr(space, name, True)
        return space.call_function(w_meth)
    unaryop.func_name = name
    return unaryop

def make_binary_returning_notimplemented_instance_method(name):
    def binaryop(self, space, w_other):
        try:
            w_meth = self.getattr(space, name, False)

    srepat.space = space
    srepat.w_pattern = w_pattern      # the original uncompiled pattern
    srepat.flags = flags
    srepat.code = code
    srepat.num_groups = groups
    srepat.w_groupindex = w_groupindex
    srepat.w_indexgroup = w_indexgroup
    return w_srepat


W_SRE_Pattern.typedef = TypeDef(
    'SRE_Pattern',
    __new__      = interp2app(SRE_Pattern__new__),
    __copy__     = interp2app(W_SRE_Pattern.cannot_copy_w),
    __deepcopy__ = interp2app(W_SRE_Pattern.cannot_copy_w),
    __weakref__  = make_weakref_descr(W_SRE_Pattern),
    findall      = interp2app(W_SRE_Pattern.findall_w),
    finditer     = interp2app(W_SRE_Pattern.finditer_w),
    match        = interp2app(W_SRE_Pattern.match_w),
    scanner      = interp2app(W_SRE_Pattern.finditer_w),    # reuse finditer()
    search       = interp2app(W_SRE_Pattern.search_w),
    split        = interp2app(W_SRE_Pattern.split_w),
    sub          = interp2app(W_SRE_Pattern.sub_w),
    subn         = interp2app(W_SRE_Pattern.subn_w),
    flags        = interp_attrproperty('flags', W_SRE_Pattern),
    groupindex   = interp_attrproperty_w('w_groupindex', W_SRE_Pattern),
    groups       = interp_attrproperty('num_groups', W_SRE_Pattern),
    pattern      = interp_attrproperty_w('w_pattern', W_SRE_Pattern),
)

# ____________________________________________________________

def W_TeeIterable___new__(space, w_subtype, w_iterable):
    # Obscure and undocumented function.  PyPy only supports w_iterable
    # being a W_TeeIterable, because the case where it is a general
    # iterable is useless and confusing as far as I can tell (as the
    # semantics are then slightly different; see the XXX in lib-python's
    # test_itertools).
    myiter = space.interp_w(W_TeeIterable, w_iterable)
    return space.wrap(W_TeeIterable(space, myiter.w_iterator,
                                           myiter.chained_list))

W_TeeIterable.typedef = TypeDef(
        'itertools._tee',
        __new__ = interp2app(W_TeeIterable___new__),
        __iter__ = interp2app(W_TeeIterable.iter_w),
        __next__ = interp2app(W_TeeIterable.next_w),
        __weakref__ = make_weakref_descr(W_TeeIterable),
        )
W_TeeIterable.typedef.acceptable_as_base_class = False


class W_GroupBy(W_Root):
    def __init__(self, space, w_iterable, w_fun):
        self.space = space
        self.w_iterable = self.space.iter(w_iterable)
        if space.is_none(w_fun):
            self.w_fun = None
        else:
            self.w_fun = w_fun
        self.index = 0
        self.lookahead = False
        self.exhausted = False

        self.keepalive = keepalive

    def descr_setitem(self, space, w_index, w_obj):
        try:
            W_Buffer.descr_setitem(self, space, w_index, w_obj)
        except OperationError as e:
            if e.match(space, space.w_TypeError):
                e.w_type = space.w_ValueError
            raise

MiniBuffer.typedef = TypeDef(
    "_cffi_backend.buffer",
    __len__ = interp2app(MiniBuffer.descr_len),
    __getitem__ = interp2app(MiniBuffer.descr_getitem),
    __setitem__ = interp2app(MiniBuffer.descr_setitem),
    __weakref__ = make_weakref_descr(MiniBuffer),
    __str__ = interp2app(MiniBuffer.descr_str),
    )
MiniBuffer.typedef.acceptable_as_base_class = False


@unwrap_spec(w_cdata=cdataobj.W_CData, size=int)
def buffer(space, w_cdata, size=-1):
    ctype = w_cdata.ctype
    if isinstance(ctype, ctypeptr.W_CTypePointer):
        if size < 0:
            structobj = w_cdata.get_structobj()
            if (structobj is not None and
                isinstance(structobj.ctype, ctypestruct.W_CTypeStructOrUnion)):
                size = structobj._sizeof()
            if size < 0:

Build an ordered collection accessible from endpoints only.""",
    __new__ = interp2app(descr__new__),
    __init__ = interp2app(W_Deque.init),
    append     = interp2app(W_Deque.append),
    appendleft = interp2app(W_Deque.appendleft),
    clear      = interp2app(W_Deque.clear),
    count      = interp2app(W_Deque.count),
    extend     = interp2app(W_Deque.extend),
    extendleft = interp2app(W_Deque.extendleft),
    pop        = interp2app(W_Deque.pop),
    popleft    = interp2app(W_Deque.popleft),
    remove     = interp2app(W_Deque.remove),
    reverse    = interp2app(W_Deque.reverse),
    rotate     = interp2app(W_Deque.rotate),
    __weakref__ = make_weakref_descr(W_Deque),
    __iter__ = interp2app(W_Deque.iter),
    __reversed__ = interp2app(W_Deque.reviter),
    __len__ = interp2app(W_Deque.length),
    __repr__ = interp2app(W_Deque.repr),
    __lt__ = interp2app(W_Deque.lt),
    __le__ = interp2app(W_Deque.le),
    __eq__ = interp2app(W_Deque.eq),
    __ne__ = interp2app(W_Deque.ne),
    __gt__ = interp2app(W_Deque.gt),
    __ge__ = interp2app(W_Deque.ge),
    __hash__ = None,
    __iadd__ = interp2app(W_Deque.iadd),
    __getitem__ = interp2app(W_Deque.getitem),
    __setitem__ = interp2app(W_Deque.setitem),
    __delitem__ = interp2app(W_Deque.delitem),