用C++求一个数的平方

template<typename t> class square
{
private:
t i;
public:
square(t i)
{
this->i=i;
}
t getsquare()
{
return i*i;
}
};

#include <iostream>

using namespace std;

template<typename T1, typename T2>
class POW2
{
public:
POW2(T1 n) : num(n) {}
T2 GetResult() const
{
T2 ret = num * num;
return ret;
}
private:
T1 num;
};

int main(int argc, char* argv[])
{
POW2 <int, long> a(2);
cout << a.GetResult() << endl;

POW2 <float, double> b(2.5f);
cout << b.GetResult() << endl;

return 0;
}