Use u8 test indices so quickcheck is less likely to go out of bounds.

tests/quick.rs

@@ -217,8 +217,12 @@ quickcheck_limit! {
  })
  }
 
- fn swap_indices(vec: Vec<u8>, a: usize, b: usize) -> TestResult {
+ // Use `u8` test indices so quickcheck is less likely to go out of bounds.
+ fn swap_indices(vec: Vec<u8>, a: u8, b: u8) -> TestResult {
  let mut set = IndexSet::<u8>::from_iter(vec);
+ let a = usize::from(a);
+ let b = usize::from(b);
+
  if a >= set.len() || b >= set.len() {
  return TestResult::discard();
  }
@@ -236,8 +240,12 @@ quickcheck_limit! {
  TestResult::passed()
  }
 
- fn move_index(vec: Vec<u8>, from: usize, to: usize) -> TestResult {
+ // Use `u8` test indices so quickcheck is less likely to go out of bounds.
+ fn move_index(vec: Vec<u8>, from: u8, to: u8) -> TestResult {
  let mut set = IndexSet::<u8>::from_iter(vec);
+ let from = usize::from(from);
+ let to = usize::from(to);
+
  if from >= set.len() || to >= set.len() {
  return TestResult::discard();
  }