c++ - cmath header confusion

Question

What is the namespace for math functions? Global or std?

Consider cos function. It has 3 overloads. But there is also legacy cos from math.h. C doesn't know anything about function overloading. Therefore cos(x) can't be resolved to cos(float). The solution is to call the single precision version explicitly cosf(x). Did I miss anything?

Answer 1

You get the same functions by including <math.c> and <cmath> in C++, the only differences is the namespace. I.E. including <math.h> also gives you the overload.

In theory, in C++03, using <math.h> gives you the symbols defined in the global namespace and also in the std namespace while using <cmath> gives you the symbols defined in the std namespace and not in the global namespace.

The practice is different and C++ 0X aligned the theory with the practice. <math.h> gives you the symbols defined in the global namespace and perhaps also in the std namespace while using <cmath> gives you the symbols defined in the std namespace and perhaps also in the global namespace.