递归模板实现单例模式
28 Mar 2013
#include <iostream>
using namespace std;
template<class T> class Singleton {
Singleton(const Singleton&);
Singleton &operator=(const Singleton&);
protected:
Singleton() {}
virtual ~Singleton() {}
public:
static T &instance() {
static T theInstance;
return theInstance;
}
};
// A sample class to be made into a Singleton
class MyClass : public Singleton<MyClass> {
int x;
protected:
friend class Singleton<MyClass>;
MyClass() { x = 0; }
public:
void setValue(int n) { x = n; }
int getValue() const { return x; }
};
int main() {
MyClass &m = MyClass::instance();
cout << m.getValue() << endl;
m.setValue(1);
cout << m.getValue() << endl;
}