make LabelledArrays an extension

[KristofferC]

No description provided.

[github-actions]

Benchmark Results

	master	aece705...	master/aece70511b5c68...
overhead/acrule/a+2	0.723 ± 0.029 μs	0.732 ± 0.018 μs	0.988
overhead/acrule/a+2+b	0.697 ± 0.025 μs	0.703 ± 0.016 μs	0.992
overhead/acrule/a+b	0.252 ± 0.011 μs	0.244 ± 0.0084 μs	1.03
overhead/acrule/noop:Int	25 ± 0.05 ns	26.2 ± 0.91 ns	0.953
overhead/acrule/noop:Sym	0.0365 ± 0.0054 μs	0.0376 ± 0.0051 μs	0.969
overhead/rule/noop:Int	0.0454 ± 0.0024 μs	0.0479 ± 0.00052 μs	0.946
overhead/rule/noop:Sym	0.0569 ± 0.0032 μs	0.0557 ± 0.0026 μs	1.02
overhead/rule/noop:Term	0.058 ± 0.0035 μs	0.056 ± 0.0029 μs	1.04
overhead/ruleset/noop:Int	0.132 ± 0.0044 μs	0.134 ± 0.0034 μs	0.984
overhead/ruleset/noop:Sym	0.163 ± 0.0073 μs	0.155 ± 0.0048 μs	1.05
overhead/ruleset/noop:Term	3.08 ± 0.14 μs	3.09 ± 0.12 μs	0.996
overhead/simplify/noop:Int	0.145 ± 0.0016 μs	0.147 ± 0.0033 μs	0.986
overhead/simplify/noop:Sym	0.154 ± 0.0057 μs	0.176 ± 0.0055 μs	0.875
overhead/simplify/noop:Term	0.0357 ± 0.0019 ms	0.0372 ± 0.0019 ms	0.959
overhead/simplify/randterm (+, *):serial	0.0888 ± 0.0016 s	0.0882 ± 0.00068 s	1.01
overhead/simplify/randterm (+, *):thread	0.0519 ± 0.035 s	0.0523 ± 0.032 s	0.993
overhead/simplify/randterm (/, *):serial	0.215 ± 0.0074 ms	0.215 ± 0.0061 ms	1
overhead/simplify/randterm (/, *):thread	0.244 ± 0.0087 ms	0.244 ± 0.0066 ms	1
overhead/substitute/a	0.0597 ± 0.0018 ms	0.0605 ± 0.0016 ms	0.988
overhead/substitute/a,b	0.0526 ± 0.0017 ms	0.0537 ± 0.0017 ms	0.979
overhead/substitute/a,b,c	17.8 ± 0.8 μs	18.1 ± 0.72 μs	0.983
polyform/easy_iszero	29.8 ± 1.9 μs	28.5 ± 1.8 μs	1.05
polyform/isone	3.1 ± 0 ns	3.1 ± 0.01 ns	1
polyform/iszero	1.15 ± 0.032 ms	1.1 ± 0.028 ms	1.05
polyform/simplify_fractions	1.69 ± 0.042 ms	1.6 ± 0.039 ms	1.06
time_to_load	4.61 ± 0.061 s	2.17 ± 0.022 s	2.12

Benchmark Plots

A plot of the benchmark results have been uploaded as an artifact to the workflow run for this PR.
Go to "Actions"->"Benchmark a pull request"->[the most recent run]->"Artifacts" (at the bottom).

[KristofferC]

I guess the CI errors is not caused by this,