Returns true if this struct is equal to other.

Both structs' instance vars are compared to each other. Thus, two structs are considered equal if each of their instance variables are equal. Subclasses should override this method to provide specific equality semantics.

struct Point
  def initialize(@x : Int32, @y : Int32)
  end
end

p1 = Point.new 1, 2
p2 = Point.new 1, 2
p3 = Point.new 3, 4

p1 == p2 # => true
p1 == p3 # => false