template < typename FloatType >
inline const bool is_NaN( FloatType number )
{
// A NaN doesn't compare equal to anything, not even itself.
return number != number;
}
If a compiler optimizes that away, it has a bug. It cannot be optimized away precisely because of the behavior of NaNs. I think you are safe.
the following function away?
template < typename FloatType >
inline const bool is_NaN( FloatType number )
{
// A NaN doesn't compare equal to anything, not even itself.
return number != number;
}
Obviously, I intend to use this to test a floating point variable for NaN (not a number) ... can't use std::isnan() because our compiler doesn't support C++11. My worry is that the compiler might optimize the whole call away, on account of comparing a number to itself being so unbelievably stupid.
One note on style, regarding the const-qualified bool return-type (note: bool is a built-in type):
"[font="Georgia"]For built-in types, it doesn’t matter whether you return by value as a const, so you should avoid confusing the client programmer and leave off the const when returning a built-in type by value."
// http://linuxtopia.or...pter08_014.html
[/font]
