Ary.flatten("")

Array#flatten e$B$N0z?t$Ke(B “” e$B$rM?$($F%(%i!<$K$J$i$J$$$N$O0U?^$;e(B
e$B$6$k5sF0$J$N$G$O$J$$$G$7$g$&$+!#e(B

% ./ruby -ve ‘p [[]].flatten("")’
ruby 1.9.0 (2007-07-12 patchlevel 0) [i686-linux]
[]