migrate to c++20

[anonrig]

Summary

• Updates codebase to use C++20
• Removes testing on gcc 10 and clang 10

Benchmarks

Running benchmarks with sudo build/benchmarks/bbc_bench

Before

--------------------------------------------------------------------------------------------
Benchmark                                  Time             CPU   Iterations UserCounters...
--------------------------------------------------------------------------------------------
BasicBench_AdaURL_href                  2205 ns         2205 ns       314272 GHz=4.81764 cycle/byte=12.0915 cycles/url=1.15944k instructions/byte=57.0452 instructions/cycle=4.71778 instructions/ns=22.7285 instructions/url=5.47k ns/url=240.667 speed=391.386M/s time/byte=2.55502ns time/url=244.998ns url/s=4.08166M/s
BasicBench_AdaURL_aggregator_href       1371 ns         1370 ns       516598 GHz=5.77944 cycle/byte=8.927 cycles/url=856 instructions/byte=40.6014 instructions/cycle=4.54816 instructions/ns=26.2858 instructions/url=3.89322k ns/url=148.111 speed=629.99M/s time/byte=1.58733ns time/url=152.207ns url/s=6.57M/s
BasicBench_AdaURL_CanParse               987 ns          987 ns       708179 GHz=7.05344 cycle/byte=7.49479 cycles/url=718.667 instructions/byte=33.2306 instructions/cycle=4.43383 instructions/ns=31.2737 instructions/url=3.18644k ns/url=101.889 speed=874.13M/s time/byte=1.14399ns time/url=109.696ns url/s=9.11607M/s
BasicBench_whatwg                       4341 ns         4341 ns       160950 GHz=4.01934 cycle/byte=19.9849 cycles/url=1.91633k instructions/byte=98.9224 instructions/cycle=4.94985 instructions/ns=19.8951 instructions/url=9.48556k ns/url=476.778 speed=198.82M/s time/byte=5.02967ns time/url=482.29ns url/s=2.07344M/s
BasicBench_CURL                        10698 ns        10690 ns        65995 GHz=3.51628 cycle/byte=43.8007 cycles/url=4.2k instructions/byte=214.015 instructions/cycle=4.88611 instructions/ns=17.1809 instructions/url=20.5217k ns/url=1.19444k speed=80.7275M/s time/byte=12.3873ns time/url=1.18781us url/s=841.886k/s

After

--------------------------------------------------------------------------------------------
Benchmark                                  Time             CPU   Iterations UserCounters...
--------------------------------------------------------------------------------------------
BasicBench_AdaURL_href                  2138 ns         2138 ns       326689 GHz=4.86541 cycle/byte=11.9803 cycles/url=1.14878k instructions/byte=55.2283 instructions/cycle=4.60992 instructions/ns=22.4292 instructions/url=5.29578k ns/url=236.111 speed=403.656M/s time/byte=2.47735ns time/url=237.551ns url/s=4.20963M/s
BasicBench_AdaURL_aggregator_href       1331 ns         1331 ns       528905 GHz=5.65641 cycle/byte=8.73696 cycles/url=837.778 instructions/byte=40.5713 instructions/cycle=4.64363 instructions/ns=26.2663 instructions/url=3.89033k ns/url=148.111 speed=648.612M/s time/byte=1.54175ns time/url=147.837ns url/s=6.7642M/s
BasicBench_AdaURL_CanParse               949 ns          949 ns       735325 GHz=6.85153 cycle/byte=7.27231 cycles/url=697.333 instructions/byte=32.993 instructions/cycle=4.53681 instructions/ns=31.0841 instructions/url=3.16367k ns/url=101.778 speed=909.01M/s time/byte=1.1001ns time/url=105.487ns url/s=9.47983M/s
BasicBench_whatwg                       4372 ns         4371 ns       160182 GHz=4.03122 cycle/byte=20.0487 cycles/url=1.92244k instructions/byte=98.445 instructions/cycle=4.9103 instructions/ns=19.7945 instructions/url=9.43978k ns/url=476.889 speed=197.427M/s time/byte=5.06515ns time/url=485.692ns url/s=2.05892M/s
BasicBench_CURL                        10625 ns        10624 ns        65867 GHz=3.60184 cycle/byte=43.9942 cycles/url=4.21856k instructions/byte=214.057 instructions/cycle=4.86557 instructions/ns=17.525 instructions/url=20.5257k ns/url=1.17122k speed=81.2314M/s time/byte=12.3105ns time/url=1.18044us url/s=847.141k/s

[lemire]

Note that this should be first release as a major release as it will break existing code.

[lemire]

@anonrig I recommend you bump this version:

ada/CMakeLists.txt

Line 39 in 59cc693

VERSION 1.14.0

[anonrig]

hey @mikea, do you know by any chance how to fix the fuzzer (oss-fuzz) to compile with C++20? even after adding -std=c++20, it still uses c++17

[lemire]

@anonrig I suggest merging. This is a non-blocking technical issue.

If you introduced a bug (very unlikely) we can fix it later.

[anonrig]

@lemire before merging this, should we release a new version with @CarlosEduR's changes?

[anonrig]

I created a new release for v2.9.2. Once the github release is available, we can merge this.