FYI: parallelly::supportsMulticore()

[HenrikBengtsson]

FYI, instead of:

can_fork <- NULL
#' @importFrom parallelly availableCores
on_load({can_fork <- availableCores("multicore") > 1L})

you could use parallelly::supportsMulticore(). Other than being more clear, the advantage would be to that it returns TRUE also when there's a single core available.