I tried to do simple template function inside the class and everything worked out. Hope this helps:
Code:
#include <iostream>

using namespace std;

class myClass {
public:
	template<typename T>
	T Max(T* numbers, int length) {
		T max = *numbers;
		for (int i = 1; i < length; i++, numbers++)
			if (*numbers > max)
				max = *numbers;
		return max;
	}

};

int main() {
	myClass C;
	float nums[] = {1,2,3,94,12,5,6,8,77};
	cout << C.Max(nums, sizeof nums / sizeof nums[0]) << endl;
	return 0;
}