fix is.guide() -> inherits()

Author: teunbrand

R/guides-.R

@@ -68,14 +68,14 @@ NULL
 #' }
 guides <- function(...) {
   args <- list2(...)
-  if (length(args) > 0) {
-    if (is.list(args[[1]]) && !is.guide(args[[1]])) args <- args[[1]]
-    args <- rename_aes(args)
   # If there are no guides do nothing
   if (length(args) == 0) {
     return(NULL)
   }
 
+  if (is.list(args[[1]]) && !inherits(args[[1]], "guide")) args <- args[[1]]
+  args <- rename_aes(args)
+
   idx_false <- vapply(args, isFALSE, FUN.VALUE = logical(1L))
   if (isTRUE(any(idx_false))) {
     deprecate_warn0("3.3.4", "guides(`<scale>` = 'cannot be `FALSE`. Use \"none\" instead')")