# Unary Operations ```py class Number: def __init__(self, value: int): self.value = 1 def __pos__(self) -> int: return +self.value def __neg__(self) -> int: return -self.value def __invert__(self) -> Literal[True]: return True a = Number() reveal_type(+a) # revealed: int reveal_type(-a) # revealed: int reveal_type(~a) # revealed: @Todo class NoDunder: ... b = NoDunder() +b # error: [unsupported-operator] "Unary operator `+` is unsupported for type `NoDunder`" -b # error: [unsupported-operator] "Unary operator `-` is unsupported for type `NoDunder`" ~b # error: [unsupported-operator] "Unary operator `~` is unsupported for type `NoDunder`" ```