NaNs make sense in number-crunching scenarios, but they absolutely don't make sense in anything even remotely resembling storing/communication. Worse than NULLs

NaNs make sense in number-crunching scenarios, but they absolutely don't make sense in anything even remotely resembling storing/communication. Worse than NULLs, really: at least those are equal to themselves. I personally think perhaps having two kinds of float/double, one for arithmetics, with full IEEE754-compliant semantics, and another for general-purpose code, where NaNs would be just normal values that you can compare with themselves and get "true", would make sense.