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  1. #include <iostream>
  2.  
  3. template < class Real >
  4. class ICovBase {
  5.     bool isTrue;
  6.     Real* This() {
  7.         return static_cast < Real* > (this);
  8.     }
  9.  public:
  10.     virtual bool operator() (int a) const {
  11.         std::cout << "Base class () called\n";
  12.         return true;
  13.     };
  14.     ICovBase(int a) {
  15.         isTrue = This()->operator()(a);
  16.     }
  17.     virtual ~ICovBase() {};
  18. };
  19.  
  20. class Cov : public ICovBase < Cov > {
  21.  public: 
  22.     bool operator () (int a) const {
  23.         std::cout << "Child class () called\n";
  24.         return (a > 0);
  25.     }
  26.     Cov(int a): ICovBase < Cov >(a) {
  27.     }
  28. };
  29.  
  30. int main() {
  31.     Cov test(5);
  32. }
Success #stdin #stdout 0.02s 2724KB
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Child class () called
https://ideone.com/zy5R4
language:
C++ (gcc 8.3)
created:
12 years ago
visibility:
public

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