$ perl -MO=Concise,-exec -MDevel::Peek -we'Dump 1; sub foo{Dump $_[0];$_[0]=1} foo(1)'
1 <0> enter
2 <;> nextstate(main 44 -e:1) v:{
3 <$> const[IV 1] s
4 <2> Devel_Peek_Dump vK/1
5 <;> nextstate(main 46 -e:1) v:{
6 <0> pushmark s
7 <$> const[IV 1] sM
8 <#> gv[IV \&main::foo] s
9 <1> entersub vKS
a <@> leave[1 ref] vKP/REFC
-e syntax OK
####
$ perl -MO=Concise,-exec -MDevel::Peek -we'Dump 1+1; sub foo{Dump $_[0];$_[0]=1} foo(1+1)'
1 <0> enter
2 <;> nextstate(main 44 -e:1) v:{
3 <$> const[IV 2] s/FOLD
4 <2> Devel_Peek_Dump vK/1
5 <;> nextstate(main 46 -e:1) v:{
6 <0> pushmark s
7 <$> const[IV 2] sM/FOLD
8 <#> gv[IV \&main::foo] s
9 <1> entersub vKS
a <@> leave[1 ref] vKP/REFC
-e syntax OK
##
##
$ perl -MDevel::Peek -e'Dump(${\1})'
SV = IV(0x8549e4010) at 0x8549e4020
REFCNT = 1
FLAGS = (IOK,READONLY,PROTECT,pIOK)
IV = 1
$ perl -MDevel::Peek -e'Dump(${\(1+1)})'
SV = IV(0x7ed5d4d610) at 0x7ed5d4d620
REFCNT = 1
FLAGS = (IOK,pIOK)
IV = 2
$ perl -MDevel::Peek -e'Dump($_) for 1'
SV = IV(0x151c4b8240) at 0x151c4b8250
REFCNT = 2
FLAGS = (IOK,READONLY,PROTECT,pIOK)
IV = 1
$ perl -MDevel::Peek -e'Dump($_) for 1+1'
SV = IV(0x567114cd90) at 0x567114cda0
REFCNT = 1
FLAGS = (IOK,pIOK)
IV = 2