@a //= ( 1..3 );;
[Can't modify array dereference in defined or assignment (//=) at (eval 9) line 1, at EOF

( @a ) //= ( 1..3 );;
[Can't modify array dereference in defined or assignment (//=) at (eval 10) line 1, at EOF

( @a ) ||= ( 1..3 );;
[Can't modify array dereference in logical or assignment (||=) at (eval 11) line 1, at EOF