ssrt_ex_022.rs

fn main() {
  println!("Hello darkness my old {}", pick_one(true, "friend", "frenemy"));
  println!("I've come to {} with you again.", pick_one(false, "dance", "talk"));
  println!("Because a {} softly creeping", pick_one(false, "gremlin", "vision"));
  println!("Left its {} while I was {}.", pick_one(true, "seeds", "cell phone"), pick_one(false, "also creeping", "sleeping"));
}

// ERROR: rust doesn't know which lifetime to pick! This or that?
fn pick_one(this_or_that: bool, this: &str, that: &str) -> &str {
  if this_or_that {
    this
  } else {
    that
  }
}