Datetime desc in Index results in arg-type error

[9dogs]

Describe the bug
mypy reports an error when datetime_col.desc() is used as an Index second argument; datetime_col (without desc) works as intended.

Expected behavior
mypy does not produce an error

To Reproduce

from sqlalchemy import Column, DateTime, Integer, Index
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()


class Model(Base):
    
    id = Column(Integer, primary_key=True)
    created_at = Column(DateTime)

    __tablename__ = 'model'
    __table_args__ = (
        # error: Argument 2 to "Index" has incompatible type "ClauseElement"; expected "ColumnClause[Any]"  [arg-type]
        Index('created_at_idx', created_at.desc()),
    )

Error

error: Argument 2 to "Index" has incompatible type "ClauseElement"; expected "ColumnClause[Any]"  [arg-type]

Versions.

• OS: dockerized python:3.9.4-buster
• Python: 3.9.4
• SQLAlchemy: 1.4.12

Have a nice day!

[CaselIT]

Thanks for reporting

@bryanforbes was this fixed by #69?

[bryanforbes]

I don't think this is fixed

[MaicoTimmerman]

I think this is fixable by making ColumnOperators generic and letting the functions return ColumnElement[_T]. I've tried looking, but is there any use-case in which the ColumnOperators functions must return a ClauseElement as they currently do?