C++模板类里的静态成员问题

#include <iostream>
using namespace std;

template <typename T>
class testClass
{
public:
	static int _data;
};

int testClass <int>::_data = 1;	//这里出错

in GCC, 必须写为下面这样, in vs , both is right.
template <typename T>
int testClass <T>::_data = 1;