Hashbrown Maps

Comparison to std::collections::HashMap

 name               stdhash ns/iter  hashbrown ns/iter  diff ns/iter    diff %  speedup
 find_existing      23,831           2,935                   -20,896   -87.68%   x 8.12
 find_nonexisting   25,326           2,283                   -23,043   -90.99%  x 11.09
 get_remove_insert  124              25                          -99   -79.84%   x 4.96
 grow_by_insertion  197              177                         -20   -10.15%   x 1.11
 hashmap_as_queue   72               18                          -54   -75.00%   x 4.00
 new_drop           14               0                           -14  -100.00%    x inf
 new_insert_drop    78               55                          -23   -29.49%   x 1.42