huangyuanbing@ubuntu:~$ g++     -std=c++17 -O3 -mtune=core-avx2 hbench.cpp -o hb && ./hb

hrd::hash_map
    insert[]: 4207
       erase: 207
    insert[]: 4146
  find_erase: 201
    insert[]: 3802
     emplace: 3696
    insert[]: 3715
        find: 148
       count: 149
ctor_initlist: 14
    insert[]: 4064
   copy_ctor: 3963
copy_operator: 4475

emhash6::HashMap
    insert[]: 3394
       erase: 183
    insert[]: 3064
  find_erase: 440
    insert[]: 3062
     emplace: 2835
    insert[]: 2980
        find: 102
       count: 101
ctor_initlist: 4
    insert[]: 3323
   copy_ctor: 9
copy_operator: 763

emhash7::HashMap
    insert[]: 3355
       erase: 465
    insert[]: 3015
  find_erase: 438
    insert[]: 3014
     emplace: 2537
    insert[]: 2891
        find: 108
       count: 107
ctor_initlist: 7
    insert[]: 3360
   copy_ctor: 8
copy_operator: 771

robin_hood::unordered_map
    insert[]: 3938
       erase: 174
    insert[]: 3700
  find_erase: 209
    insert[]: 3720
     emplace: 3074
    insert[]: 3468
        find: 131
       count: 128
ctor_initlist: 6
    insert[]: 3946
   copy_ctor: 1883
copy_operator: 552

tsl::robin_map
    insert[]: 3837
       erase: 211
    insert[]: 3427
  find_erase: 735
    insert[]: 3427
     emplace: 3192
    insert[]: 3364
        find: 156
       count: 157
ctor_initlist: 60
    insert[]: 3833
   copy_ctor: 3301
copy_operator: 1342

parallel-hashmap::flat_map
    insert[]: 10382
       erase: 459
    insert[]: 10246
  find_erase: 408
    insert[]: 10256
     emplace: 3303
    insert[]: 10549
        find: 161
       count: 159
ctor_initlist: 8
    insert[]: 10419
   copy_ctor: 3337
copy_operator: 3435