Simple Singleton Example

From : http://sourcemaking.com/design_patterns/singleton/cpp/1

class GlobalClass { ... static GlobalClass *instance() { if (!s_instance) s_instance = new GlobalClass; return s_instance; } ... }; // Allocating and initializing GlobalClass's // static data member. The pointer is being // allocated - not the object inself. GlobalClass *GlobalClass::s_instance = 0; void foo(void) { GlobalClass::instance()->set_value(1); cout << "foo: global_ptr is " << GlobalClass::instance()->get_value() << '\n'; }     위에서 보는 것처럼 단지 공유 객체 포인터를 static으로만 선언하는 것만으로는불 충분하다. 좀 괜찮게 보일 될려면 GlobalClass::instance() 이렇게 한 꺼풀더 씌우자

From : http://sourcemaking.com/design_patterns/singleton/cpp/1