int a; …; (a == a) fails?

Question

if we set float and double type to NaN then they are not equal to anything including themselves.
can such a thing happens for

Answer 1

NaN is the only value for a==a return false.

And int doesn't support a NaN value. So no you can't have this situation with int.

Another note, to check if a value is NaN you should use isnan() not a==a.

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