Scala mutable collections and "Reference must be prefixed warnings"

Question

I have to use a mutable linked list for a specific use case. However I'd like to avoid "Reference must be prefixed" warnings. Aliasing the import seems to be a solution: ``` import scala.collection.mutable.{LinkedList => MutableLinkedList} ``` it works on most cases except in pattern matching an empty LinkedList, this still produces the warning: ``` case MutableLinkedList() => // do Something ``` the only way I can remove this warning seems to be to do a fully qualified case check on an empty list: ``` case scala.collection.mutable.LinkedList() => // do Something ``` Why does the first case not get rid of the warning?

Accepted Answer

Just import `mutable` package:

```
import collection.mutable
```

and use it with any mutable collection:

```
mutable.LinkedList(1, 2, 3)
```

or if you prefer more concise variant:

```
import collection.{mutable => m}
m.LinkedList(1, 2, 3)
```

It will work with pattern matching also.

Scala mutable collections and "Reference must be prefixed warnings"

Solution

Problem