On the other hand,

If you want to use horrible and/or (somewhat) obfuscated code, you could try:

sub shifty {
   my $v = (shift)-1;
   map { return ++$v } map { $v |= $v >> $_ } (1,2,4,8,16);
}
[download]

or alternately (the readable version):

sub shifty2 {
   my $v = (shift)-1;
   $v |= $v >> $_ foreach (1,2,4,8,16);
   return ++$v;
}
[download]

i don't know why i was compelled to post that, but i knew one could reduce the repition and possibly obfuscate the code a little with some obviously useless uses of map doing things it wasn't meant to do...
my $0.02;

jynx