Returns -1, 0 or +1 depending on whether the Chars object is to be sorted before, equal or after the object on the right side of the operation. It accepts any object that implements to_s. See String#<=> for more details.
'Ã©'.mb_chars <=> 'Ã¼'.mb_chars #=> -1
# File activesupport/lib/active_support/multibyte/chars.rb, line 139 def <=>(other) @wrapped_string <=> other.to_s end