Nan, Infinity Etc.

[Baker]

[revelator]

[Baker]

The more I think about this, the less I like the idea of this.

Maybe I'll just add some extra flag to a struct, use a macro to check for weird values within the struct, and if in some future date some real solution that can be expected to operate properly on any platform, just change the definition of the macro.

After reading up more and more on this, the solutions all look essentially terrible.

[andrewj]

[Baker]

[taniwha]

First, I agree: best to avoid using nan and inf. They seem to be best for indicating bad input (and to a certain extent, the nature of the badness).

One problem with nan is nan is never equal to anything, even nan (ie, comparison always fails).

Inf is sort of useful: you can compare against it (so it's good for initializing min/max (you have + and - inf)), but that's about it. Forget doing any actual math with inf. I had the bright idea of using inf for initializing windings in qf's bsp compiler. Worked wonderfully for min/max but broke completely for clipping.