一个基于C++11的单例模板类

Posted 2020-12-30 codecomposer

 1 #ifndef _SINGLETON_H_
 2 #define _SINGLETON_H_
 3 
 4 #include <mutex>
 5 #include <memory>
 6 
 7 template<typename T>
 8 class Singleton {
 9 public:
10   template <typename... ArgTypes>
11   static T* getInstance(ArgTypes... args) {
12     static std::once_flag of;
13     std::call_once(of, init(std::forward<Args>(args)...));
14 
15     return instance_.get();
16   }
17 private:
18   Singleton() = delete;
19   ~Singleton() = delete;
20   Singleton(const Singleton&) = delete;
21   Singleton(Singleton&&) = delete;
22   Singleton& operator=(const Singleton&) = delete;
23   Singleton& operator=(Singleton&&) = delete;
24 
25   template <typename... ArgTypes>
26   static void init(ArgTypes... args) {
27     instance_.reset(new T(std::forward<ArgTypes>(args)...));
28   }
29 
30   static std::unique_ptr<T> instance_;
31 };
32 
33 template<class T> 
34 std::unique_ptr<T> Singleton<T>::instance_ = nullptr;
35 
36 #endif