lvalue tip

while — very unfortunately — this

irb(main):042:0> x,y=0,0
=> [0, 0]
irb(main):044:0> if nil then x else y end = 1
SyntaxError: compile error
(irb):44: syntax error, unexpected '=', expecting $end
if nil then x else y end = 1
                          ^
    from (irb):44
    from :0

does not work, this

irb(main):048:0> x,y=[],[]
=> [[], []]
irb(main):049:0> if nil then x else y end << 1
=> [1]
irb(main):050:0> x
=> []
irb(main):051:0> y
=> [1]

performs nicely.

i know the difference, but it's still controversial to me.