>perl -MDevel::Peek -le"my @a = qw(a b c); print @a-1; Dump \@a,1"
2
SV = RV(0x238c60) at 0x238c54
  REFCNT = 1
  FLAGS = (TEMP,ROK)
  RV = 0x182a22c
  SV = PVAV(0x239a4c) at 0x182a22c
    REFCNT = 2
    FLAGS = (PADMY)
    ARRAY = 0x182521c
    FILL = 2
    MAX = 3
    ARYLEN = 0x0
    FLAGS = (REAL)