While writing some test cases, and some of the tests check for the result of a NaN.
I tried using std::isnan but the assert failes:
Assertion `std::isnan(x)' failed.
After printing the value of x, it turned out it's negative NaN (-nan) which is totally acceptable in my case.
After trying to use the fact that NaN != NaN and using assert(x == x), the compiler does me a 'favor' and optimises the assert away.
Making my own isNaN function is being optimised away as well.
How can I check for both equality of NaN and -NaN?