add insert!

[bkamins]

Fixes #74

[codecov]

Codecov Report

Merging #75 (f80d58e) into main (f87b540) will increase coverage by 0.36%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main      #75      +/-   ##
==========================================
+ Coverage   86.64%   87.00%   +0.36%     
==========================================
  Files           1        1              
  Lines         322      331       +9     
==========================================
+ Hits          279      288       +9     
  Misses         43       43              

Impacted Files	Coverage Δ
src/PooledArrays.jl	87.00% <100.00%> (+0.36%)	⬆️

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[quinnj]

LGTM; we don't need to worry about the copy-on-write business at all here or in push!, right?

[bkamins]

Copy-on-write is handled here https://github.com/JuliaData/PooledArrays.jl/blob/main/src/PooledArrays.jl#L567, which gets called if a new entry needs to be added.

However push! and insert! are not thread safe - should me mention this in the docs or this is obvious?

[quinnj]

Ah, that's right; I missed that it gets handled from the getpoolidx call. Yeah, I think it'd be worth mentioning that they aren't threadsafe; it would hopefully be obvious to most users, since they aren't threadsafe for Base Array, but it doesn't hurt as a reminder.

[bkamins]

OK - I have added comments (I think it does not make much sense to add a docstring as it would be the same as for general push! and insert!)

[bkamins]

Thank you!

I will make a release.