perl -MDevel::Peek -e'$x = 3; qq($x); $x+=1; Dump $x; $y=$x; Dump $y'
SV = PVIV(0x15d75f4) at 0x15d57e4
  REFCNT = 1
  FLAGS = (IOK,pIOK)
  IV = 4
  PV = 0x1a53acc "3"\0
  CUR = 1
  LEN = 2
SV = PVIV(0x15d7604) at 0x15d64d4
  REFCNT = 1
  FLAGS = (IOK,pIOK)
  IV = 4
  PV = 0