Question

So I’m writing a bit of code that needs to raise a function’s return value to a certain power. I recently discovered that using the ‘^’ operator for exponentiation is useless because in C++ it is actually an XOR operator or something like that. Now here’s the code I want to write:

int answer = pow(base, raisingTo(power));

Now can anyone tell me if this is right? I’ll explain the code. I’ve declared an int variable answer as you all are aware of, and initialized it to the value of any variable called ‘base’, raised to the return value of the raisingTo() function acting on any other variable called ‘power’. When I do this (and I edit & compile my code in Visual C++ 2010 Express Edition), a red dash appears under the word ‘pow’ and an error appears saying: “more than one instance of overloaded function ‘pow’ matches the argument list”

Can someone please solve this problem for me? And could you guys also explain to me how this whole pow() function actually works, cos frankly http://www.cplusplus.com references are a little confusing as I am still only a beginner!

Answer 1

The documentation states it pretty explicitly already:

The pow(int, int) overload is no longer available. If you use this overload, the compiler may emit C2668 [EDIT: That’s the error you get]. To avoid this problem, cast the first parameter to double, float, or long double.

Also, to calculate base^power you just write

pow(base, power)

And with above hint:

int result = (int) pow((double)base, power);