floating-point - C99 and floating point environment

Question

I was looking at new features of C99 and saw the floating point environment:

#include <fenv.h>

My question is simple. If I'm performing floating point number computations, do I have to include the above preprocessor directive in my code? If no, then what does this directive do and when does it become important to include?

Thanks a lot...

Answer 1

You only need to include the fenv.h header if you intend to use any of the features it provides. Those features are described here-

Answer 2

cfenv可能不是很相关，但 C++11 现在还包括通过头文件对 C99 浮点环境函数的支持。