terraform-provider-google/examples/example-versioned-module/ip/main.tf

resource "google_compute_address" "ip_address" {
  # We'll only generate this block if the value of
  # has_labels is 0! Effectively an if statement.
  count = "${1 - local.has_labels}"

  name = "${var.name}"
}

resource "google_compute_address" "ip_address_beta" {
  # And this block is only present if we have
  # at least one entry, effectively an elif.
  count = "${local.has_labels}"

  name   = "${var.name}"
  labels = "${var.labels}"
}