sri@odyssey:~$ perl -MO=Concise -e 'print ++$i'
7  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) v ->3
6     <@> print vK ->7
3        <0> pushmark s ->4
5        <1> preinc sK/1 ->6
-           <1> ex-rv2sv sKRM/1 ->5
4              <#> gvsv[*i] s ->5
-e syntax OK
sri@odyssey:~$ perl -MO=Concise -e 'print $i++'
7  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) v ->3
6     <@> print vK ->7
3        <0> pushmark s ->4
5        <1> postinc[t2] sK/1 ->6
-           <1> ex-rv2sv sKRM/1 ->5
4              <#> gvsv[*i] s ->5
-e syntax OK