A modern programming language that makes developers happier.

kotlinlang

Replace `where` syntax

current:
```class Foo&lt;A, B&gt;(val a: A, val b: B) where A: Bar, A: Baz```

proposed:
```class Foo&lt;A: Bar &amp; Baz, B&gt;(val a: A, val b: B)```

not like `&amp;` is getting any use in Kotlin anyhow...

Also, a shoot-for-the-moon proposal:

Adding `or` functionality, similar to how it is used in javascript.
A quick example of how that would be really nice:
``` fun &lt;N: Byte | Int | Float | Double&gt; areaByMetres(length: N, width: N) = Area(length.toDouble().metre, width.toDouble().metre)```
To allow for `areaByMetres` to accept any number type that can be safely cast up to Double for either of its params would take 8 more declarations of the function. If we were doing this for volume, then it would take 27 more. Yikes!

Of course allowing for multiple possible types has _a lot_ more ramifications, and I imagine would be very difficult to add to a strongly typed language, and is arguably no longer strongly typed.

I think the expectation is that you'd use sealed classes for unions like that. In this situation, of course, the sealed classes require an extra allocation. Maybe value types on the JVM will save us one day?

There's a lot of discussion (including comments by the Kotlin devs) here, you might be interested: <https://discuss.kotlinlang.org/t/union-types/77>