Hash Map Benchmark

Benchmark results from @martinus' benchmark suite comparing cista::raw::hash_map with absl::flat_hash_map, both with Abseil's hashing function.

Hardware: Late 2013 Mac Book Pro
Compiler: Clang 8.0.1 (Release build)

Test Case	Operation	Cista Timing	Cista Memory	Absl Timing	Absl Memory
CtorDtorEmptyMap	ctor & dtor empty map	1.12e-07	0.0078125	0.234575	0.015625
CtorDtorSingleEntryMap	ctor & dtor map with 1 entry	5.56329	0.0898438	11.0391	0.128906
InsertHugeInt	insert 100M int	15.8582	1872.02	17.5138	1872.15
InsertHugeInt	clear 100M int	0.0713953	1872.02	0.0686353	1872.15
InsertHugeInt	reinsert 100M int	15.7225	1872.08	17.5115	1872.18
InsertHugeInt	remove 100M int	17.1535	1872.08	19.2849	1872.18
InsertHugeInt	destructor empty map	0.0728455	1872.08	0.0635276	1872.18
IterateIntegers	iterate while adding	4.69787	2.14453	4.92399	2.21484
IterateIntegers	iterate while removing	7.03086	2.14453	6.47078	2.21484
RandomDistinct2	5% distinct	4.7003	72.0156	5.08918	72.1367
RandomDistinct2	25% distinct	7.76231	288.07	8.70536	288.176
RandomDistinct2	50% distinct	7.77399	576.07	9.11769	576.18
RandomDistinct2	100% distinct	7.34941	1008.12	8.95751	1008.18
RandomFindString	0% 100 byte	4.34817	19.1953	4.48878	19.2305
RandomFindString	25% 100 byte	6.5731	19.2539	7.08621	19.3906
RandomFindString	50% 100 byte	8.11409	19.3906	8.72445	19.3984
RandomFindString	75% 100 byte	9.3175	19.3906	9.99143	19.457
RandomFindString	100% 100 byte	10.1794	19.3906	10.7499	19.457
RandomFindString_1000000	0% 13 byte	7.07453	132.023	8.11859	132.105
RandomFindString_1000000	25% 13 byte	11.8328	132.078	12.9541	132.109
RandomFindString_1000000	50% 13 byte	15.4782	132.133	17.0503	132.152
RandomFindString_1000000	75% 13 byte	19.2234	132.133	21.1135	132.207
RandomFindString_1000000	100% 13 byte	22.6994	132.133	25.4145	132.207
RandomFind_200	0% success, 0x00000000ffffffff	8.67311	0.0351562	6.58513	0.101562
RandomFind_200	0% success, 0xffffffff00000000	8.58912	0.0742188	6.52341	0.101562
RandomFind_200	25% success, 0x00000000ffffffff	8.64899	0.0859375	6.89964	0.121094
RandomFind_200	25% success, 0xffffffff00000000	8.64513	0.0898438	6.8236	0.132812
RandomFind_200	50% success, 0x00000000ffffffff	8.55242	0.09375	7.23126	0.136719
RandomFind_200	50% success, 0xffffffff00000000	8.54506	0.09375	7.22895	0.152344
RandomFind_200	75% success, 0x00000000ffffffff	8.90019	0.09375	7.65427	0.15625
RandomFind_200	75% success, 0xffffffff00000000	8.74963	0.09375	7.66632	0.15625
RandomFind_200	100% success, 0x00000000ffffffff	8.45687	0.101562	8.26679	0.15625
RandomFind_200	100% success, 0xffffffff00000000	8.62689	0.101562	8.47051	0.15625
RandomFind_2000	0% success, 0x00000000ffffffff	9.76519	0.167969	7.10302	0.25
RandomFind_2000	0% success, 0xffffffff00000000	9.80477	0.234375	7.24574	0.265625
RandomFind_2000	25% success, 0x00000000ffffffff	9.7026	0.253906	7.61493	0.265625
RandomFind_2000	25% success, 0xffffffff00000000	9.51166	0.28125	7.74619	0.289062
RandomFind_2000	50% success, 0x00000000ffffffff	9.44472	0.285156	8.21549	0.296875
RandomFind_2000	50% success, 0xffffffff00000000	9.54861	0.285156	8.56908	0.308594
RandomFind_2000	75% success, 0x00000000ffffffff	9.31456	0.285156	8.64818	0.335938
RandomFind_2000	75% success, 0xffffffff00000000	9.81131	0.285156	8.30809	0.335938
RandomFind_2000	100% success, 0x00000000ffffffff	9.00024	0.285156	8.72585	0.355469
RandomFind_2000	100% success, 0xffffffff00000000	8.93084	0.304688	8.77032	0.355469
RandomFind_500000	0% success, 0x00000000ffffffff	7.52929	34.0234	5.96099	34.1055
RandomFind_500000	0% success, 0xffffffff00000000	7.37669	34.0781	6.00151	34.1484
RandomFind_500000	25% success, 0x00000000ffffffff	11.6983	34.1328	10.426	34.1914
RandomFind_500000	25% success, 0xffffffff00000000	11.4675	34.1328	9.34607	34.2109
RandomFind_500000	50% success, 0x00000000ffffffff	12.985	34.1328	12.6532	34.2109
RandomFind_500000	50% success, 0xffffffff00000000	12.6394	34.1875	12.7567	34.2148
RandomFind_500000	75% success, 0x00000000ffffffff	13.0588	34.1875	13.2993	34.2188
RandomFind_500000	75% success, 0xffffffff00000000	13.1818	34.1875	13.2336	34.2188
RandomFind_500000	100% success, 0x00000000ffffffff	13.3784	34.1875	13.6424	34.2188
RandomFind_500000	100% success, 0xffffffff00000000	13.2573	34.1875	13.3657	34.2188
RandomInsertErase	4 bits, 50M cycles	1.40953	0.0078125	1.88005	0.101562
RandomInsertErase	8 bits, 50M cycles	1.67877	0.0546875	2.45452	0.128906
RandomInsertErase	12 bits, 50M cycles	1.51409	0.3125	2.25051	0.382812
RandomInsertErase	16 bits, 50M cycles	1.98252	4.29688	2.29844	4.36719
RandomInsertErase	20 bits, 50M cycles	4.64053	34.0469	5.10594	68.1172
RandomInsertErase	24 bits, 50M cycles	8.12249	544.047	9.25093	544.117
RandomInsertEraseStrings	7 bytes	4.57359	98.0195	5.49265	98.1133
RandomInsertEraseStrings	8 bytes	4.11311	98.0195	5.30464	98.1562
RandomInsertEraseStrings	13 bytes	4.61626	98.0898	5.77753	98.2148
RandomInsertEraseStrings	100 bytes	7.21546	138.051	7.25815	138.223
RandomInsertEraseStrings	1000 bytes	6.54804	183.109	6.59536	184.23