Meaning of %||% in R

Question

Found in roxygen2 code the shortcut :

%||%

No help can be found with

?"%||%"

It looks like a shortcut for union() but how could I display it's definition ?

Answer 1

From source (utils.R from roxygen2_4.1.1.tar.gz)

"%||%" <- function(a, b) {
  if (!is.null(a)) a else b
}