C:\test>perl -MTime::HiRes=time 
-wE"my @a= 0..1e6; my $t= time;my @bla= @a; tr[0][]d for @bla; say time-$t; <>"
0.488373041152954


C:\test>perl -MTime::HiRes=time 
-wE"my @a= 0..1e6;my $t= time;my @bla= map{tr/h//d; $_}map{$_} @a;say time-$t; <>"
32.5820000171661