c:\@Work\Perl>perl -wMstrict -le
"print $];
 ;;
 my (@streams, @spaces);
 my $y = 'Y';
 push (($y eq 'Y' ? @streams : @spaces), 'Z');
 print qq{(@streams) (@spaces)};
"
5.014004
Not an ARRAY reference at -e line 1.

c:\@Work\Perl>perl -wMstrict -le
"print $];
 ;;
 my (@streams, @spaces);
 my $y = 'Y';
 push (($y eq 'Y' ? \@streams : \@spaces), 'Z');
 print qq{(@streams) (@spaces)};
"
5.014004
(Z) ()