c++单例模式出错
代码如下,竟然出现编译错误:error LNK2001: 无法解析的外部符号 "private: static class Singleton * Singleton::instance" (?instance@Singleton@@0PAV1@A)
class Singleton
{
public:
static Singleton *GetSingleton()
{
if(instance==NULL) instance=new Singleton();
return instance;
}
~Singleton()
{
cout<<"析构函数"<<endl;
}
private:
Singleton(){};
static Singleton*instance;
};
int main()
{
Singleton*p=Singleton::GetSingleton();
return 0;
}