### using 5.010
[~]# time perl hash_test_benchmark.pl
        Rate assign double
assign 119/s     --    -2%
double 122/s     2%     --

real    2m30.601s
user    2m17.789s
sys     0m6.317s

### without 5.010
[~]# time perl hash_test_benchmark.pl
        Rate double assign
double 121/s     --    -0%
assign 122/s     0%     --

real    2m32.598s
user    2m19.745s
sys     0m6.498s
[~]#