irb(main)> s = Struct.new(:a, :b, :c)
=> #<Class:0x0000000107407718>

irb(main)> s1 = s.new(1, 2, 3)
=> #<struct  a=1, b=2, c=3>

irb(main)> s1.to_a
=> [1, 2, 3]

irb(main)> a = s1.to_a
=> [1, 2, 3]

irb(main)> s2 = s.new(*a)
=> #<struct  a=1, b=2, c=3>