Idea for robin-hood-hashing V2 about robin-hood-hashing HOT 1 CLOSED

I have a good implemention of spare hash map https://github.com/ktprime/emhash/blob/master/hash_table8.hpp
it's the fastest iteration compared with other's hash map, but it's not efficient for erasion/insertion if Key/Value is large.
it need 8 bytes index for each key/value pair.

bench_IterateIntegers map = emhash5
total iterate/removing time = 5.44, 11.98|1127848008

bench_IterateIntegers map = emhash8
total iterate/removing time = 0.39, 1.17

bench_IterateIntegers map = emhash7
total iterate/removing time = 1.00, 2.78

bench_IterateIntegers map = emhash6
total iterate/removing time = 1.08, 2.92

bench_IterateIntegers map = rigtorp
total iterate/removing time = 5.38, 13.14

bench_IterateIntegers map = martinus flat
total iterate/removing time = 3.02, 9.06

bench_IterateIntegers map = phmap flat
total iterate/removing time = 3.38, 8.23

bench_IterateIntegers map = emilib3
total iterate/removing time = 1.69, 4.48

bench_IterateIntegers map = emilib2
total iterate/removing time = 1.62, 4.34

bench_IterateIntegers map = absl flat
total iterate/removing time = 3.27, 8.28

from robin-hood-hashing.