use Benchmark 'cmpthese';

my %hash = ( key => 'value' );

cmpthese( -3, {
   with =>		sub {delete $INC{'strict.pm'}; use strict 'refs'; my $a = 1; my $b = 2},
   without =>	sub {$hash{key} = delete $hash{key};              my $a = 1; my $b = 2},
} );

__END__
P:\test>..\bin\perl.exe  junk.pl8
            Rate without    with
without  24308/s      --    -82%
with    136483/s    461%      --