A modern programming language that makes developers happier.

kotlinlang

Let's say I want a collection, a deferred or whatever, of 2 types.

Do you recommend:

```//1
Something&lt;Pair&lt;A, B&gt;&gt;```

```//2
data class Other&lt;A, B&gt;(...)
Something&lt;Other&lt;A, B&gt;&gt;```

```//3
typealias Other&lt;A, B&gt; = Pair&lt;A, B&gt;
Something&lt;Other&lt;A, B&gt;&gt;```

I'm expecting that the answer is "it depends", what are some good examples to choose which one to use?

Only use `Pair` unless:
* You intend to access the fields not by decomposition frequently.
* At least one of your type arguments is a concrete type and the compound type is used a lot in your code
* You have special functionality for the type (such as member functions)
* Your code is performance sensitive and you want to store primitive types in the compound

If any of the conditions are true, just make a data class in one line of code.

I don't recommend using typealias very much at all

Typealias is sadly a pretty underwhelming language feature at the moment

But not that useful. Often times I would use an interface with a function instead of a lambda type if I want to name it, for example.