3 elements d h w

: spaces  ( n- )  &space times ;
: ---     ( -  )  '+ putc @w 2 * [ '- putc ] times '+ putc ;
: ?       ( n- )  @h <> [ '| ] [ '+ ] if ;
: slice   ( n- )  '/ putc @w 2 * spaces '/ putc @d swap - dup spaces ? putc cr ;
: |...|/  ( -  )  @h [ '| putc @w 2 * spaces '| putc 1- spaces '/ putc cr ] iterd ;
: face    ( -  )
   ---    @w 1+ spaces '/ putc cr
  |...|/
   ---    cr ;

: cuboid  ( whd- )
  !d !h !w cr
  @d 1+ spaces --- cr
  @d [ dup spaces slice ] iterd
  face ;

2 3 4 cuboid