perl -MDevel::Peek -e '$a = 1; Dump ($a); %a = map +{$_}, $a; Dump ($a)'
SV = IV(0x8192edc) at 0x8191dc4
  REFCNT = 1
  FLAGS = (IOK,pIOK)
  IV = 1
SV = PVIV(0x8184888) at 0x8191dc4
  REFCNT = 1
  FLAGS = (IOK,POK,pIOK,pPOK)
  IV = 1
  PV = 0x818b5b8 "1"\0
  CUR = 1
  LEN = 2