`"" + columnRef` becomes `String` about dataframe HOT 3 CLOSED

It should indeed be fixed but unfortunately we can't. It's a language limitation.

Have you tried making a function like operator fun String.plus(something)?

Since String already has a function plus, an extension function overload will never be called by default.

from dataframe.

I would consider deprecating, and ultimately removing:

public operator fun ColumnReference<String>.plus.

from dataframe.

Might indeed be a good idea to add ColumReference<String>.append() and .prepend() or something similar and through deprecations steer users to those :)
We still cannot prevent "" + anything from becoming a String though

from dataframe.