the scalar itself is really being stored to the container, or fetched from the container, instead of its copy

Its got two parts.

$array[0] = $i;
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is really something like

$array[0] = sv_mortalcopy($i);
[download]

There is no av_store_copy, there is av_store and sv_mortalcopy.

Seems somebody already thought about this some

https://github.com/Leont/libperl--/blob/master/perl++/headers/array.h

https://github.com/Leont/libperl--/blob/master/perl++/doc/Array.pod