Reference Classes are built into base R and function similarly to R6 but are built on top of S4.
Advanced Object-Oriented Programming in R: Strategic Selection Advanced Object-Oriented Programming in R: Stat...
S3 is R’s original, informal OOP system. It is essentially a list with a "class" attribute. Reference Classes are built into base R and
Requires an external dependency; can lead to "non-idiomatic" R code if overused. 4. Reference Classes (RC): The Internal Alternative Advanced Object-Oriented Programming in R: Stat...