Hyperpolyglot: PHP, Perl, Python, Ruby
x.succ is not the Ruby equivalent of ++$x in PHP (or Perl). x.succ <i>returns</i> x + 1 (by default, on integers) but does not <i>increment</i> x as ++$x does (since numbers are immutable and that's what "x" is giving us in Ruby). The closest match would be x += 1 (shorthand for x = x + 1). I don't see x = x.succ in common usage but that would work too.