Other languages can definitely do it:

Ruby:

    class X
      attr_accessor :y
    end

Crystal (full working example):

    class Y
    end

    class X
      def initialize(y : Y)
        @y = y
      end

      def y
        @y
      end
    end

    y = Y.new
    x = X.new(y: y)
    puts x.y