There are comparison benchmarks between ByteSet and the following types:

• [bool; 256]
• BinaryHeap<u8>
• BTreeSet<u8>
• HashSet<u8>
• InclusiveRange<u8>
• Vec<u8>

What other types should be compared against?

Type for intersection, union, subtract and difference are missing from index.js.flow.

x = sample(1000)
y = sample(1000)

sx = Set$new(x)
sy = Set$new(y)

microbenchmark::microbenchmark(
  setdiff(x, y),
  sx - sy,
  unit = "s"
)

Gives a mean time in seconds of:

setdiff(x,y) = 4.681405e-05
sx - sy = 1.639163e-02

A considerable difference. The additional bloat is due to a lot of checks that sort through the correct dispatch methods and use tricks for