add note about base::inherits() in ?S7_inherits. (RConsortium#488)

Author: t-kalinowski

R/inherits.R

@@ -10,6 +10,9 @@
 #' @returns
 #' * `S7_inherits()` returns a single `TRUE` or `FALSE`.
 #' * `check_is_S7()` returns nothing; it's called for its side-effects.
+#'
+#' @note Starting with \R 4.3.0, `base::inherits()` can accept an S7 class as
+#' the second argument, supporting usage like `inherits(x, Foo)`.
 #' @export
 #' @examples
 #' Foo1 <- new_class("Foo1")
@@ -21,6 +24,9 @@
 #'
 #' S7_inherits(Foo1(), Foo2)
 #' try(check_is_S7(Foo1(), Foo2))
+#'
+#' if (getRversion() >= "4.3.0")
+#'   inherits(Foo1(), Foo1)
 S7_inherits <- function(x, class = NULL) {
   if (!(is.null(class) || inherits(class, "S7_class"))) {
     stop("`class` must be an <S7_class> or NULL")