perl -v
This is perl 5, version 24, subversion 1 (v5.24.1)

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perldoc experimental

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The supported features, documented further below, are:

    array_base - allow the use of $[ to change the starting index of @array
    autoderef  - allow push, each, keys, and other built-ins on references
    ...

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Array and hash container functions accept references

Using this feature triggered warnings in the category experimental::autoderef .

Superseded by Postfix dereference syntax.

Introduced in Perl 5.14.0

Removed in Perl 5.24.0