In functional programming, it's customary to apply...

# language-proposals

[dmitry.petrov]

In functional programming, it's customary to apply aggressive optimizations based on additional information about side effects (and lack of them) to get rid of intermediate data structures that arise in such code.
It's a matter of long-time discussions whether we could do that in Kotlin, and how we should do it.
C2 can sometimes scalarize such objects. Not so sure about ART.