Ambiguous overload call to abs(double)

Question

I have the following C++ code:

#include 
#include       // per http://www.cplusplus.com/reference/clibrary/cmath/abs/

// snip .         


        

Answer 1

Its boils down to this: math.h is from C and was created over 10 years ago. In math.h, due to its primitive nature, the abs() function is "essentially" just for integer types and if you wanted to get the absolute value of a double, you had to use fabs(). When C++ was created it took math.h and made it cmath. cmath is essentially math.h but improved for C++. It improved things like having to distinguish between fabs() and abs, and just made abs() for both doubles and integer types. In summary either: Use math.h and use abs() for integers, fabs() for doubles or use cmath and just have abs for everything (easier and recommended)

Hope this helps anyone who is having the same problem!