Here's another way, although it uses an additional temporary variable... 
my $b = "abefcdghijklmn";
my @a = (['start 0'], ['start 1']);
my $i = 0;
push @{ $a[$i++ % 2] }, $_ for unpack('(A)*', $b);

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Jeff japhy Pinyan, P.L., P.M., P.O.D, X.S.: Perl, regex, and perl hacker
How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart

In reply to Re^3: need to put values (from unpack) into array-ref by japhy
in thread need to put values (from unpack) into array-ref by jeanluca

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