5: Improve solution for Rust track exercise "Leap".

Dependencies

• [2] YSCR6EHO 4: Add solution for Rust track exercise "Leap".
• [3] XN7GOFDN 3: Add Rust track exercise "Leap".

Change contents

• replacement in rust/leap/src/lib.rs at line 8
  [2.1361]→[2.1361:1409](∅→∅)
  − fn a(a: u64, b: u64) -> bool {

  − a % b == 0

  − }
  [2.1361]

  [2.1409]
  + let a = move |b: u64| year % b == 0;
• replacement in rust/leap/src/lib.rs at line 10
  [2.1410]→[2.1410:1491](∅→∅)
  − a(year, 80000) || !a(year, 3200) && a(year, 400) || !a(year, 100) && a(year, 4)
  [2.1410]

  [3.2367]
  + a(4) ^ a(100) ^ a(400) ^ a(3200) ^ a(80000)