[wolco]

Go back to 2017. Mutable programming is back because of the benefits it offers

[sundbry]

An efficient immutable vector can be concatenated much faster without any reallocation of either array; one would probably outperform .push for bigger arrays in this case.

[BubRoss]

How is that true? push shouldn't be reallocating the array on each call. You seem to be alluding to a linked list of arrays.