def endpoint(self, endpoint: str) -> t.Callable[[F], F]:
        """Decorate a view function to register it for the given
        endpoint. Used if a rule is added without a ``view_func`` with
        :meth:`add_url_rule`.

        .. code-block:: python

            app.add_url_rule("/ex", endpoint="example")

            @app.endpoint("example")
            def example():
                ...

        :param endpoint: The endpoint name to associate with the view
            function.
        """

        def decorator(f: F) -> F:
            self.view_functions[endpoint] = f
            return f

        return decorator
Decorate a view function to register it for the given
        endpoint. Used if a rule is added without a ``view_func`` with
        :meth:`add_url_rule`.

        .. code-block:: python

            app.add_url_rule("/ex", endpoint="example")

            @app.endpoint("example")
            def example():
                ...

        :param endpoint: The endpoint name to associate with the view
            function.
        
src/flask/sansio/scaffold.py