Implement SSDict

[Maxcode123]

Builtin dict API:

class dict(MutableMapping[_KT, _VT], Generic[_KT, _VT]):
    # NOTE: Keyword arguments are special. If they are used, _KT must include
    #       str, but we have no way of enforcing it here.
    @overload
    def __init__(self, **kwargs: _VT) -> None: ...
    @overload
    def __init__(self, map: Mapping[_KT, _VT], **kwargs: _VT) -> None: ...
    @overload
    def __init__(self, iterable: Iterable[Tuple[_KT, _VT]], **kwargs: _VT) -> None: ...
    def __new__(cls: Type[_T1], *args: Any, **kwargs: Any) -> _T1: ...
    def clear(self) -> None: ...
    def copy(self) -> Dict[_KT, _VT]: ...
    def popitem(self) -> Tuple[_KT, _VT]: ...
    def setdefault(self, __key: _KT, __default: _VT = ...) -> _VT: ...
    @overload
    def update(self, __m: Mapping[_KT, _VT], **kwargs: _VT) -> None: ...
    @overload
    def update(self, __m: Iterable[Tuple[_KT, _VT]], **kwargs: _VT) -> None: ...
    @overload
    def update(self, **kwargs: _VT) -> None: ...
    def keys(self) -> KeysView[_KT]: ...
    def values(self) -> ValuesView[_VT]: ...
    def items(self) -> ItemsView[_KT, _VT]: ...
    @classmethod
    @overload
    def fromkeys(cls, __iterable: Iterable[_T]) -> Dict[_T, Any]: ...
    @classmethod
    @overload
    def fromkeys(cls, __iterable: Iterable[_T], __value: _S) -> Dict[_T, _S]: ...
    def __len__(self) -> int: ...
    def __getitem__(self, k: _KT) -> _VT: ...
    def __setitem__(self, k: _KT, v: _VT) -> None: ...
    def __delitem__(self, v: _KT) -> None: ...
    def __iter__(self) -> Iterator[_KT]: ...
    if sys.version_info >= (3, 8):
        def __reversed__(self) -> Iterator[_KT]: ...
    def __str__(self) -> str: ...
    __hash__: None  # type: ignore
    if sys.version_info >= (3, 9):
        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
        def __or__(self, __value: Mapping[_KT, _VT]) -> Dict[_KT, _VT]: ...
        def __ior__(self, __value: Mapping[_KT, _VT]) -> Dict[_KT, _VT]: ...