Here's how:

@slice = @{$array_ref}[ @idx ];
@slice = @{$hash_ref}{ @keys };
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And there's no easy way to "pretend" a list is a hash. You need to use a hash reference explicitly:

$scalar = {1, 'a', 2, 'b'}->{$key};
@slice = @{ { 1, 'a', 2, 'b' } }{ @keys };
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