When does it typically make sense in programming to be testing the equality of two floating point numbers?i.e. a == b where both a & b are floats. My naive impression is that one would always test the difference against some tolerance epsilon. Am I wrong? Can testing the equality of floats be meaningful in certain contexts? Any examples from the wild? i.e. From real codebases or applications out there on git etc. PS. I'm implicit assuming that using the equality operator on floats is indeed meaningful in some contexts; otherwise why would most programming languages allow it. 
Testing equality of two floats: Realistic example
floating point