MyIntEnum.ONE should be passable to functions expecting Literal[1] arguments

Bug Report

This is related but distinct from #19576, #16327, and #17162. It's also not specific to IntEnums, but I use them in the example for clarity. StrEnums as well as enums based on (int, Enum), or (str, Enum), etc.

To Reproduce

import enum
from typing import Literal

type One = Literal[1]
type Two = Literal[2]
type Three = Literal[3]

def option(arg: One | Two | Three) -> None:
    ...

class MyEnum(enum.IntEnum):
    ONE = 1
    TWO = 2
    THREE = 3

option(MyEnum.TWO)  #  error: Argument 1 to "option" has incompatible type "Literal[MyEnum.TWO]"; expected "Literal[1, 2, 3]"  [arg-type]

Expected Behavior

No error reported.

Actual Behavior

The error in the comment in the example is a false positive. This code works fine at runtime.

Your Environment

• Mypy version used: master as of 0d791b29b7ba4e5a9b04c0b6bdba11faf4a186a2
• Python version used: 3.13

Commencez par exécuter l’exemple fourni en Python 3.13 avec mypy master et suivez le traitement des arguments Literal impliquant MyEnum.TWO. La correction est complète lorsque l’exemple ne signale plus d’erreur d’argument incompatible, tout en préservant le comportement associé de enum et de Literal décrit dans l’issue.