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  1. #include <iostream>
  2. #include <type_traits>
  3.  
  4. template<typename Derived>
  5. class MyObject {
  6. public:
  7.     MyObject() : theRealInstance(static_cast<Derived*>(this)) {
  8.         // Check the available interface as soon an instance is created
  9.         void (Derived::*op1)(void) = &Derived::methodImpl;
  10.         (void)op1;
  11.     }
  12.  
  13.     void method() { 
  14.         theRealInstance->methodImpl(); 
  15.     }
  16.  
  17. private:
  18.     Derived* theRealInstance;
  19. };
  20.  
  21. struct MyImpl : public MyObject<MyImpl> {
  22.     void methodImpl() { std::cout << "method implementation" << std::endl; }
  23. };
  24.  
  25. struct MyWrongImpl : public MyObject<MyWrongImpl> {
  26. };
  27.  
  28. void test_alias(){
  29.     MyImpl m;
  30.     m.method();
  31.  
  32.     // Uncomment to see the compile time error
  33.     // MyWrongImpl w;
  34. }
  35.  
  36. int main() {
  37. 	test_alias();
  38. 	return 0;
  39. }
Success #stdin #stdout 0s 3340KB
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method implementation
https://ideone.com/4PcuqO
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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