<https://twitter.com/kotlin/status/114345126500075...

# announcements

[user]

https://twitter.com/kotlin/status/1143451265000759296
Use !is and !in - the counterparts of is and in operators https://pl.kotl.in/S19yPNXpX

https://pbs.twimg.com/media/D8sdPOCXoAAp9WD.png▾

Twitter

[Jonathan Mew]

🤔 odd example for !is

[marstran]

@Jonathan Mew You could ask a dog to meow, but he won't do anything 😄

[Dico]

You couldn't ask a dog to meow, there would be a compiler error

[Jonathan Mew]

@Dico well according to the example, you can ask any animal to meow, which is why the example is odd 🙂

[Dico]

No, meow could be declared on Cat, in which case animal is smart casted to Cat

[Dico]

Because there is ample evidence that animal is a Cat following the function's first statement

[Jonathan Mew]

. . . if (animal !is Cat) 🙀

[karelpeeters]

Well yeah, if it's you a cat you return and the second line never even runs. So by the time the second line actually happens you can be sure it's a cat.

[Jonathan Mew]

Oh god. I've been reading it as if (animal !is Cat) return animal.meow()
Thank you for saving me from myself. I'll go get some more sleep now.

[karelpeeters]

Well then you've been reading correctly your code linewrapped for me, great.

[SiebelsTim]

Braces around if save animals