Is there a standard sign function (signum, sgn) in C/C++?

Question

I want a function that returns -1 for negative numbers and +1 for positive numbers. http://en.wikipedia.org/wiki/Sign_function It's easy enough to write my own, but it seems like something that ought to be in a standard library somewhere. Edit: Specifically, I was looking for a function working on floats.

Answer 1

you can compare the number from 0

if(num>=0)

return(+1)

else

return(-1)

or you can add a flag to the if statement and return that flag

for mathematical operations include the header line

#include<maths.h>

or stl library