#! perl -slw
use strict;
use Benchmark qw[ cmpthese ];

our @tests = (
    (undef)  x1000,
    ('')     x1000,
    (chr(0)) x1000,
    (0)      x1000,
    (1)      x1000,
    ('fred') x1000,
);
cmpthese -1, {
    a => q[ !(defined && length() ) and 1 for @tests; ],
    b => q[ !defined || $_ eq ''    and 1 for @tests; ],
};

__END__
C:\test>junk
    Rate    b    a
b 1029/s   -- -17%
a 1239/s  20%   --

C:\test>junk
    Rate   b   a
b 1065/s  -- -1%
a 1079/s  1%  --