$ 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