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  1.     #include <iostream>
  2.  
  3.     template<class Derived>
  4.     class CRTP {
  5.     protected:
  6.       Derived * derived_this() {
  7.         return static_cast<Derived *>(this);
  8.       }
  9.     };
  10.  
  11.     template<class Derived>
  12.     struct Parent : public CRTP<Derived> {
  13.     private:
  14.       using CRTP<Derived>::derived_this;
  15.     public:
  16.       int y() {
  17.         return derived_this()->x();
  18.       }
  19.     };
  20.  
  21.     struct Child : public Parent<Child> {
  22.       int x() {
  23.         return 5;
  24.       }
  25.       int z() {
  26.         return y();
  27.       }
  28.     };
  29.  
  30.     int main() {
  31.       std::cout << Child().z() << std::endl;
  32.       return 0;
  33.     }
  34.  
Success #stdin #stdout 0.01s 2724KB
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Standard input is empty
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5
https://ideone.com/fAcgA
language:
C++ (gcc 8.3)
created:
12 years ago
visibility:
public

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