or download this
>perl -MTime::HiRes=time -MHash::Util=hv_store -wE"%h=();$t=time;hv_st
+ore(%h,'foo',42) for 1..1e8;say time-$t"
10.8255708217621
...
10.5545630455017
$ perl -MTime::HiRes=time -MArray::RefElem=hv_store -wE'%h=();$t=time;
+hv_store(%h,"foo",42) for 1..1e8;say time-$t'
12.1946179866791