[WalterBright]

> Seems C++ only added it in C++11

I added it to Digital Mars C and C++ in the early 1990s. Also full NaN support in all the math.h functions. AFAIK it was the first C compiler to do it.

It was based on a specification worked out by NCEG (Numerical C Extensions Group), a long forgotten group that tried to modernize C numerics support.

> the fast math is as good as the accurate math

I was more interested in correct results than fast wrong answers.

[BeetleB]

Yes, but for most C++ applications, they prefer the faster wrong answers, because the wrong answers are not wrong enough to cause any bugs.