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

our @a = 1 .. 1e6;

cmpthese -1, {
    a => q[ @a = map $_*  1, @a ],
    b => q[      map $_*= 1, @a     ],
    c => q[          $_*= 1 for @a      ],
};

__END__
C:\test>BuksBench.pl
    Rate    a    c    b
a 3.46/s   -- -68% -68%
c 10.7/s 208%   --  -2%
b 10.8/s 213%   2%   --