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  1. #include <iostream>
  2. using namespace std;
  3.  
  4. class B {
  5. public:
  6.     B() {
  7.     	// complex initializations
  8.     };
  9.     virtual int doSomething()
  10.     {return 2 * doSomethingHelper();}
  11.  
  12.   protected:
  13.     class initialiser {
  14.     public: 
  15.         initialiser(B*b) {b->init();}
  16.     };
  17.     void init() {  //  the rest of the what you wanted in constructor 
  18.       int a = doSomething();
  19.       // more complex stuff with `a`
  20.     }
  21.     virtual int doSomethingHelper() = 0;
  22. };
  23.  
  24.  
  25. class C:  public  B {
  26. public: 
  27.  protected:
  28.     B::initialiser bi{this}; // this truggers automaticcaly the second phase
  29.     virtual int doSomethingHelper()
  30.     {cout <<"OK"<<endl; return 1;}
  31. };
  32.  
  33. int main() {
  34.   C c;
  35.   return 0;
  36. }
  37.  
Success #stdin #stdout 0s 3096KB
comments ()
stdin 
Standard input is empty
stdout 
OK
https://ideone.com/1lSElA
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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