Inconsistent dataclass declaration

The dataclass decorator in the typeshed package has an inconsistency in its overloads. Specifically, when cls is passed explicitly as None, it is unclear whether additional arguments (e.g., init, repr, etc.) should be allowed or not. The current implementation allows passing cls=None alongside additional arguments, but this usage is not explicitly documented or validated.

Expected Behavior

The overloads should clearly define and document the behavior of cls=None when additional arguments are provided:

If allowed, the typing should reflect that explicitly.
If not allowed, the implementation should prevent or warn against such usage.

Current Behavior

Passing cls=None with arguments like kw_only=True is allowed, but this behavior is not described in the overloads. For example:

decorator = dataclass(None, kw_only=True)
@decorator
class MyClass:
    x: int

The above works but is ambiguous in terms of type checking and intended usage.

首先定位 typeshed 包中的 dataclass 装饰器重载，并将其与所示的 dataclass(None, kw_only=True) 示例进行比较。确定是否支持带有其他参数的 cls=None，然后让重载和文档一致地表达这一决定。当对于类型检查器和用户而言，该行为都明确无歧义时，即视为完成。