/* The branches in this function exhibit Rust's optional implicit return
   values, which can be utilized where a more "functional" style is preferred.
   Unlike C++ and related languages, Rust's `if` construct is an expression
   rather than a statement, and thus has a return value of its own. */
fn recursive_factorial(n: int) -> int {
    if n <= 1 { 1 }
    else { n * recursive_factorial(n-1) }
}