diff --git a/Lib/enum.py b/Lib/enum.py
index 17deb4b..82be1fb 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -391,13 +391,15 @@ def __prepare__(metacls, cls, bases, **kwds):
                     )
         return enum_dict
 
-    def __new__(metacls, cls, bases, classdict, boundary=None, **kwds):
+    def __new__(metacls, cls, bases, classdict, *, boundary=None, _simple=False, **kwds):
         # an Enum class is final once enumeration items have been defined; it
         # cannot be mixed with other types (int, float, etc.) if it has an
         # inherited __new__ unless a new __new__ is defined (or the resulting
         # class will fail).
         #
         # remove any keys listed in _ignore_
+        if _simple:
+            return super().__new__(metacls, cls, bases, classdict, **kwds)
         classdict.setdefault('_ignore_', []).append('_ignore_')
         ignore = classdict['_ignore_']
         for key in ignore:
@@ -695,7 +697,7 @@ def __setattr__(cls, name, value):
         """
         member_map = cls.__dict__.get('_member_map_', {})
         if name in member_map:
-            raise AttributeError('Cannot reassign members.')
+            raise AttributeError('Cannot reassign member %r.' % (name, ))
         super().__setattr__(name, value)
 
     def _create_(cls, class_name, names, *, module=None, qualname=None, type=None, start=1, boundary=None):
@@ -750,7 +752,8 @@ def _create_(cls, class_name, names, *, module=None, qualname=None, type=None, s
 
         return metacls.__new__(metacls, class_name, bases, classdict, boundary=boundary)
 
-    def _convert_(cls, name, module, filter, source=None, boundary=None):
+    def _convert_(cls, name, module, filter, source=None, *, boundary=None):
+
         """
         Create a new Enum subclass that replaces a collection of global constants
         """
@@ -777,7 +780,10 @@ def _convert_(cls, name, module, filter, source=None, boundary=None):
         except TypeError:
             # unless some values aren't comparable, in which case sort by name
             members.sort(key=lambda t: t[0])
-        cls = cls(name, members, module=module, boundary=boundary or KEEP)
+        body = {t[0]: t[1] for t in members}
+        body['__module__'] = module
+        tmp_cls = type(name, (object, ), body)
+        cls = _simple_enum(etype=cls, boundary=boundary or KEEP)(tmp_cls)
         cls.__reduce_ex__ = _reduce_ex_by_name
         global_enum(cls)
         module_globals[name] = cls
@@ -855,7 +861,7 @@ def _find_new_(classdict, member_type, first_enum):
         __new__ = classdict.get('__new__', None)
 
         # should __new__ be saved as __new_member__ later?
-        save_new = __new__ is not None
+        save_new = first_enum is not None and __new__ is not None
 
         if __new__ is None:
             # check all possibles for __new_member__ before falling back to
@@ -879,7 +885,7 @@ def _find_new_(classdict, member_type, first_enum):
         # if a non-object.__new__ is used then whatever value/tuple was
         # assigned to the enum member name will be passed to __new__ and to the
         # new enum member's __init__
-        if __new__ is object.__new__:
+        if first_enum is None or __new__ in (Enum.__new__, object.__new__):
             use_args = False
         else:
             use_args = True
@@ -1189,7 +1195,7 @@ def _missing_(cls, value):
             pseudo_member = object.__new__(cls)
         else:
             pseudo_member = (__new__ or cls._member_type_.__new__)(cls, value)
-        if not hasattr(pseudo_member, 'value'):
+        if not hasattr(pseudo_member, '_value_'):
             pseudo_member._value_ = value
         if member_value:
             pseudo_member._name_ = '|'.join([
@@ -1383,3 +1389,308 @@ def global_enum(cls):
         cls.__repr__ = global_enum_repr
     sys.modules[cls.__module__].__dict__.update(cls.__members__)
     return cls
+
+def _simple_enum(etype=Enum, *, boundary=None, use_args=None):
+    """
+    Class decorator that converts a normal class into an :class:`Enum`.  No
+    safety checks are done, and some advanced behavior (such as
+    :func:`__init_subclass__`) is not available.  Enum creation can be faster
+    using :func:`simple_enum`.
+
+        >>> from enum import Enum, _simple_enum
+        >>> @_simple_enum(Enum)
+        ... class Color:
+        ...     RED = auto()
+        ...     GREEN = auto()
+        ...     BLUE = auto()
+        >>> Color
+        <enum 'Color'>
+    """
+    def convert_class(cls):
+        nonlocal use_args
+        cls_name = cls.__name__
+        if use_args is None:
+            use_args = etype._use_args_
+        __new__ = cls.__dict__.get('__new__')
+        if __new__ is not None:
+            new_member = __new__.__func__
+        else:
+            new_member = etype._member_type_.__new__
+        attrs = {}
+        body = {}
+        if __new__ is not None:
+            body['__new_member__'] = new_member
+        body['_new_member_'] = new_member
+        body['_use_args_'] = use_args
+        body['_generate_next_value_'] = gnv = etype._generate_next_value_
+        body['_member_names_'] = member_names = []
+        body['_member_map_'] = member_map = {}
+        body['_value2member_map_'] = value2member_map = {}
+        body['_member_type_'] = member_type = etype._member_type_
+        if issubclass(etype, Flag):
+            body['_boundary_'] = boundary or etype._boundary_
+            body['_flag_mask_'] = None
+            body['_all_bits_'] = None
+            body['_inverted_'] = None
+        for name, obj in cls.__dict__.items():
+            if name in ('__dict__', '__weakref__'):
+                continue
+            if _is_dunder(name) or _is_private(cls_name, name) or _is_sunder(name) or _is_descriptor(obj):
+                body[name] = obj
+            else:
+                attrs[name] = obj
+        if cls.__dict__.get('__doc__') is None:
+            body['__doc__'] = 'An enumeration.'
+        #
+        # double check that repr and friends are not the mixin's or various
+        # things break (such as pickle)
+        # however, if the method is defined in the Enum itself, don't replace
+        # it
+        enum_class = type(cls_name, (etype, ), body, boundary=boundary, _simple=True)
+        for name in ('__repr__', '__str__', '__format__', '__reduce_ex__'):
+            if name in body:
+                continue
+            class_method = getattr(enum_class, name)
+            obj_method = getattr(member_type, name, None)
+            enum_method = getattr(etype, name, None)
+            if obj_method is not None and obj_method is class_method:
+                setattr(enum_class, name, enum_method)
+        gnv_last_values = []
+        if issubclass(enum_class, Flag):
+            # Flag / IntFlag
+            single_bits = multi_bits = 0
+            for name, value in attrs.items():
+                if isinstance(value, auto) and auto.value is _auto_null:
+                    value = gnv(name, 1, len(member_names), gnv_last_values)
+                if value in value2member_map:
+                    # an alias to an existing member
+                    redirect = property()
+                    redirect.__set_name__(enum_class, name)
+                    setattr(enum_class, name, redirect)
+                    member_map[name] = value2member_map[value]
+                else:
+                    # create the member
+                    if use_args:
+                        if not isinstance(value, tuple):
+                            value = (value, )
+                        member = new_member(enum_class, *value)
+                        value = value[0]
+                    else:
+                        member = new_member(enum_class)
+                    if __new__ is None:
+                        member._value_ = value
+                    member._name_ = name
+                    member.__objclass__ = enum_class
+                    member.__init__(value)
+                    redirect = property()
+                    redirect.__set_name__(enum_class, name)
+                    setattr(enum_class, name, redirect)
+                    member_map[name] = member
+                    member._sort_order_ = len(member_names)
+                    value2member_map[value] = member
+                    if _is_single_bit(value):
+                        # not a multi-bit alias, record in _member_names_ and _flag_mask_
+                        member_names.append(name)
+                        single_bits |= value
+                    else:
+                        multi_bits |= value
+                    gnv_last_values.append(value)
+            enum_class._flag_mask_ = single_bits
+            enum_class._all_bits_ = 2 ** ((single_bits|multi_bits).bit_length()) - 1
+            # set correct __iter__
+            member_list = [m._value_ for m in enum_class]
+            if member_list != sorted(member_list):
+                enum_class._iter_member_ = enum_class._iter_member_by_def_
+        else:
+            # Enum / IntEnum / StrEnum
+            for name, value in attrs.items():
+                if isinstance(value, auto):
+                    if value.value is _auto_null:
+                        value.value = gnv(name, 1, len(member_names), gnv_last_values)
+                    value = value.value
+                if value in value2member_map:
+                    # an alias to an existing member
+                    redirect = property()
+                    redirect.__set_name__(enum_class, name)
+                    setattr(enum_class, name, redirect)
+                    member_map[name] = value2member_map[value]
+                else:
+                    # create the member
+                    if use_args:
+                        if not isinstance(value, tuple):
+                            value = (value, )
+                        member = new_member(enum_class, *value)
+                        value = value[0]
+                    else:
+                        member = new_member(enum_class)
+                    if __new__ is None:
+                        member._value_ = value
+                    member._name_ = name
+                    member.__objclass__ = enum_class
+                    member.__init__(value)
+                    member._sort_order_ = len(member_names)
+                    redirect = property()
+                    redirect.__set_name__(enum_class, name)
+                    setattr(enum_class, name, redirect)
+                    member_map[name] = member
+                    value2member_map[value] = member
+                    member_names.append(name)
+                    gnv_last_values.append(value)
+        if '__new__' in body:
+            enum_class.__new_member__ = enum_class.__new__
+        enum_class.__new__ = Enum.__new__
+        return enum_class
+    return convert_class
+
+def _test_simple_enum(checked_enum, simple_enum):
+    """
+    A function that can be used to test an enum created with :func:`_simple_enum`
+    against the version created by subclassing :class:`Enum`::
+
+        >>> from enum import Enum, _simple_enum, _test_simple_enum
+        >>> @_simple_enum(Enum)
+        ... class Color:
+        ...     RED = auto()
+        ...     GREEN = auto()
+        ...     BLUE = auto()
+        >>> class CheckedColor(Enum):
+        ...     RED = auto()
+        ...     GREEN = auto()
+        ...     BLUE = auto()
+        >>> _test_simple_enum(CheckedColor, Color)
+
+    If differences are found, a :exc:`TypeError` is raised.
+    """
+    failed = []
+    if checked_enum.__dict__ != simple_enum.__dict__:
+        checked_dict = checked_enum.__dict__
+        checked_keys = list(checked_dict.keys())
+        simple_dict = simple_enum.__dict__
+        simple_keys = list(simple_dict.keys())
+        member_names = set(
+                list(checked_enum._member_map_.keys())
+                + list(simple_enum._member_map_.keys())
+                )
+        for key in set(checked_keys + simple_keys):
+            if key in ('__module__', '_member_map_', '_value2member_map_'):
+                # keys known to be different
+                continue
+            elif key in member_names:
+                # members are checked below
+                continue
+            elif key not in simple_keys:
+                failed.append("missing key: %r" % (key, ))
+            elif key not in checked_keys:
+                failed.append("extra key:   %r" % (key, ))
+            else:
+                checked_value = checked_dict[key]
+                simple_value = simple_dict[key]
+                if callable(checked_value):
+                    continue
+                if key == '__doc__':
+                    # remove all spaces/tabs
+                    compressed_checked_value = checked_value.replace(' ','').replace('\t','')
+                    compressed_simple_value = simple_value.replace(' ','').replace('\t','')
+                    if compressed_checked_value != compressed_simple_value:
+                        failed.append("%r:\n         %s\n         %s" % (
+                                key,
+                                "checked -> %r" % (checked_value, ),
+                                "simple  -> %r" % (simple_value, ),
+                                ))
+                elif checked_value != simple_value:
+                    failed.append("%r:\n         %s\n         %s" % (
+                            key,
+                            "checked -> %r" % (checked_value, ),
+                            "simple  -> %r" % (simple_value, ),
+                            ))
+        failed.sort()
+        for name in member_names:
+            failed_member = []
+            if name not in simple_keys:
+                failed.append('missing member from simple enum: %r' % name)
+            elif name not in checked_keys:
+                failed.append('extra member in simple enum: %r' % name)
+            else:
+                checked_member_dict = checked_enum[name].__dict__
+                checked_member_keys = list(checked_member_dict.keys())
+                simple_member_dict = simple_enum[name].__dict__
+                simple_member_keys = list(simple_member_dict.keys())
+                for key in set(checked_member_keys + simple_member_keys):
+                    if key in ('__module__', '__objclass__'):
+                        # keys known to be different
+                        continue
+                    elif key not in simple_member_keys:
+                        failed_member.append("missing key %r not in the simple enum member %r" % (key, name))
+                    elif key not in checked_member_keys:
+                        failed_member.append("extra key %r in simple enum member %r" % (key, name))
+                    else:
+                        checked_value = checked_member_dict[key]
+                        simple_value = simple_member_dict[key]
+                        if checked_value != simple_value:
+                            failed_member.append("%r:\n         %s\n         %s" % (
+                                    key,
+                                    "checked member -> %r" % (checked_value, ),
+                                    "simple member  -> %r" % (simple_value, ),
+                                    ))
+            if failed_member:
+                failed.append('%r member mismatch:\n      %s' % (
+                        name, '\n      '.join(failed_member),
+                        ))
+        for method in (
+                '__str__', '__repr__', '__reduce_ex__', '__format__',
+                '__getnewargs_ex__', '__getnewargs__', '__reduce_ex__', '__reduce__'
+            ):
+            if method in simple_keys and method in checked_keys:
+                # cannot compare functions, and it exists in both, so we're good
+                continue
+            elif method not in simple_keys and method not in checked_keys:
+                # method is inherited -- check it out
+                checked_method = getattr(checked_enum, method, None)
+                simple_method = getattr(simple_enum, method, None)
+                if hasattr(checked_method, '__func__'):
+                    checked_method = checked_method.__func__
+                    simple_method = simple_method.__func__
+                if checked_method != simple_method:
+                    failed.append("%r:  %-30s %s" % (
+                            method,
+                            "checked -> %r" % (checked_method, ),
+                            "simple -> %r" % (simple_method, ),
+                            ))
+            else:
+                # if the method existed in only one of the enums, it will have been caught
+                # in the first checks above
+                pass
+    if failed:
+        raise TypeError('enum mismatch:\n   %s' % '\n   '.join(failed))
+
+def _old_convert_(etype, name, module, filter, source=None, *, boundary=None):
+    """
+    Create a new Enum subclass that replaces a collection of global constants
+    """
+    # convert all constants from source (or module) that pass filter() to
+    # a new Enum called name, and export the enum and its members back to
+    # module;
+    # also, replace the __reduce_ex__ method so unpickling works in
+    # previous Python versions
+    module_globals = sys.modules[module].__dict__
+    if source:
+        source = source.__dict__
+    else:
+        source = module_globals
+    # _value2member_map_ is populated in the same order every time
+    # for a consistent reverse mapping of number to name when there
+    # are multiple names for the same number.
+    members = [
+            (name, value)
+            for name, value in source.items()
+            if filter(name)]
+    try:
+        # sort by value
+        members.sort(key=lambda t: (t[1], t[0]))
+    except TypeError:
+        # unless some values aren't comparable, in which case sort by name
+        members.sort(key=lambda t: t[0])
+    cls = etype(name, members, module=module, boundary=boundary or KEEP)
+    cls.__reduce_ex__ = _reduce_ex_by_name
+    cls.__repr__ = global_enum_repr
+    return cls