$ perl -MDevel::Peek -e 'Dump(1); Dump("1")';
SV = IV(0x21490e8) at 0x21490f8
  REFCNT = 1
  FLAGS = (IOK,READONLY,PROTECT,pIOK)
  IV = 1
SV = PV(0x2129fa0) at 0x2149168
  REFCNT = 1
  FLAGS = (POK,IsCOW,READONLY,PROTECT,pPOK)
  PV = 0x218fef0 "1"\0
  CUR = 1
  LEN = 10
  COW_REFCNT = 0
$ perl -MDevel::Peek -e '$a=42; $a="Hello"; Dump($a)';
SV = PVIV(0x83d2e0) at 0x8321f0
  REFCNT = 1
  FLAGS = (POK,IsCOW,pPOK)
  IV = 42
  PV = 0x834920 "Hello"\0
  CUR = 5
  LEN = 10
  COW_REFCNT = 1