fork download
copy 
  1. #include <iostream>
  2. #include <memory>
  3.  
  4.     template<typename T>
  5.     struct Holder {
  6.        Holder() {
  7.           std::cout << "Holder()::Holder()" << std::endl;
  8.           if (!Self)  Self = new T();
  9.           Self->Init();
  10.        }
  11.        ~Holder() {
  12.           if (Self) {
  13.              Self->Cleanup();
  14.              delete Self;
  15.              std::cout << "~Holder()::Holder()" << std::endl;
  16.           }
  17.        }
  18.        T* Self = nullptr;
  19.     };
  20.  
  21.  
  22.     ////////////////////////////////////////////////////////////////////////////////////////
  23.  
  24.     template <typename T>
  25.     class Singleton {
  26.     public:
  27.        static T* Instance() {
  28.           std::cout << "Singlton::Instance()" << std::endl;
  29.           static Holder<T> Dummy;
  30.           return Dummy.Self;
  31.        }
  32.     private:
  33.        Singleton() = delete;
  34.        Singleton(Singleton const&) = delete;
  35.        Singleton& operator= (Singleton const&) = delete;
  36.        Singleton(Singleton const&&) = delete;
  37.        Singleton& operator= (Singleton const&&) = delete;
  38.     };
  39.  
  40.     class SomeClass
  41.     {
  42.     public:
  43.        void Init()
  44.        {
  45.           connect();
  46.           initialize();
  47.        }
  48.  
  49.        void Cleanup()
  50.        {
  51.           disconnect();
  52.        }
  53.  
  54.        void connect()
  55.        {
  56.           std::cout << "connect" << std::endl;
  57.        }
  58.  
  59.        void disconnect()
  60.        {
  61.           std::cout << "disconnect" << std::endl;
  62.        }
  63.  
  64.        void initialize()
  65.        {
  66.           std::cout << "initialize" << std::endl;
  67.           throw "Aaaaaaaaaaaaaaaaa";
  68.        }
  69.        int member;
  70.     };
  71.  
  72.     int main()
  73.     {
  74.        {
  75.           auto pInst = Singleton<SomeClass>::Instance();
  76.           pInst->member = 10;
  77.           std::cout << pInst->member << std::endl;
  78.        }
  79.        auto pInst = Singleton<SomeClass>::Instance();
  80.        pInst->member = 20;
  81.  
  82.        return 0;
  83.     }
Runtime error #stdin #stdout #stderr 0s 15240KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Singlton::Instance()
Holder()::Holder()
connect
initialize
stderr
copy 
terminate called after throwing an instance of 'char const*'
https://ideone.com/8l75us
language:
C++14 (gcc 8.3)
created:
5 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!