Closure example

func foo(closure: Void -> Void)
{
  closure()
}

// correct syntax
foo({
  println("Hello")
})

// convenience syntax
foo {
  println("Hello")
}

// incorrect, compiler does not know what "foo" is:
foo
{
  println("Hello")
}

// this does work however:
foo(
  {
    println("Hello")
  }
)