===.rb

# Seen lots of code that uses === in favor of is_a? to do type checking
# Just discovered a subtle bug from the lack of symmetry of this method

irb(main):001:0> String === "Foo"
=> true
irb(main):002:0> "Foo" === String
=> false

# May not seem intuitive at first but the ordering is significant because === is a method!
# The first uses Class#=== and the second uses String#===, only the former has the type checking semantics