Branching on a condition

Branching on a condition is done with a common if, if else, or if else if else construct, as in this example:

// from Chapter 3/code/ifelse.rs 
fn main() { 
  let dead = false; 
  let health = 48; 
  if dead { 
    println!("Game over!"); 
       return; 
  } 
  if dead { 
    println!("Game over!"); 
    return; 
  } else { 
    println!("You still have a chance to win!"); 
  } 
  if health >= 50 { 
      println!("Continue to fight!"); 
  } else if health >= 20  { 
      println!("Stop the battle and gain strength!"); 
  } else { 
      println!("Hide and try to recover!"); 
  } 
} 

This gives the following output:

    You still have a chance to win!
    Stop the battle and gain strength!

The condition after the if statement has to be a Boolean. However, unlike in C, the condition must...