tic-tac-toe.rb

wins = [
  # rows
  0b000000111,
  0b000111000,
  0b111000000,
  # cols
  0b100100100,
  0b010010010,
  0b001001001,
  # diags
  0b100010001,
  0b001010100
]

board = 0b101010111

puts(wins.any? { |w| w & board == w })

Nice idea!
But it lacks one crucial feature, which is to tell if a cell has been filled or not ;)

- O -
O - O
X X X

If nil would equal 0, the wrong person would have won in this case ;)

Oh... it's not my idea :)
It's a check from player's perspective.
So there is no need for "empty cell" state.