Possible to avoid including whole standard header file because of one method?

Question

I would like to call the "C" function

fabs(double);

numerous times in my program, but I don't want to include the whole header file. Is this possible?

Answer 1

It doesn't hurt to include the whole file.
Not used stuff will not be compiled into your executable.

Answer 2

Yep, you can manually prototype it. Just add

double fabs(double x);

to the top of your source file.

Answer 3

you could declare the function yourself, but why would you want to avoid including the header file ?