fork download
copy 
  1. #include <iostream>
  2. using namespace std;
  3.  
  4. class Object
  5. {
  6.     virtual void print() = 0;
  7. };
  8.  
  9. class SingletonBase : public Object
  10. {
  11. private:
  12.     static SingletonBase* theOnlyTrueInstance;
  13. protected:
  14.     SingletonBase()
  15.     {
  16.         if(!theOnlyTrueInstance)
  17.             theOnlyTrueInstance = this;
  18.     }
  19.     virtual ~SingletonBase(){}
  20. public:
  21.     static SingletonBase* instance()
  22.     {
  23.         if (!theOnlyTrueInstance) initInstance();
  24.         return theOnlyTrueInstance;
  25.     }
  26.     void print()
  27.     { cout<<"Singleton"<<endl; }
  28.     static void initInstance()
  29.     { new SingletonBase; }
  30. };
  31.  
  32. SingletonBase* SingletonBase::theOnlyTrueInstance = 0;
  33.  
  34. class OtherBase : public Object
  35. {
  36. public:
  37.     virtual string printSymbol() = 0;
  38.     void print()
  39.     { cout<<printSymbol(); }
  40. };
  41.  
  42. class SingletonChild : public SingletonBase , public OtherBase
  43. {
  44. public:
  45.     string printSymbol()
  46.     {
  47.         return "Test";
  48.     }
  49.     static void initInstance()
  50.     { new SingletonChild; }
  51. };
  52.  
  53. int main() {
  54.     SingletonChild::initInstance();
  55.     SingletonChild* test = (SingletonChild*)SingletonChild::instance();
  56.     test->OtherBase::print();
  57.     return 0;
  58. }
Success #stdin #stdout 0s 3464KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Test
https://ideone.com/fsKimI
language:
C++14 (gcc 8.3)
created:
7 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!