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  1. #include <vector>
  2. #include <string>
  3. #include <iostream>
  4.  
  5. using namespace std;
  6.  
  7. struct constrain{
  8.   typedef double  (*callback_t) (constrain *obj, vector <double> &x_var);
  9.   string                              name;
  10.   int                            direction;
  11.   callback_t evaluate_f;
  12.  
  13.   // helper function
  14.   double evaluate(vector <double> &x_var) {
  15.     return evaluate_f(this, x_var);
  16.   }
  17. };
  18.  
  19. double func1(constrain *obj, vector<double> &p) {
  20.   cout << obj->name << ", " << obj->direction << ", " << p.size() << endl;
  21. }
  22.  
  23. int main() {
  24.   constrain ob;
  25.   ob.name = "o";
  26.   ob.direction = 1;
  27.   vector<double> v(5);
  28.  
  29.   ob.evaluate_f = &func1;
  30.   ob.evaluate_f(&ob, v);
  31.   ob.evaluate(v);
  32. }
Success #stdin #stdout 0.02s 2812KB
comments (?)
stdin 
Standard input is empty
stdout 
o, 1, 5
o, 1, 5
https://ideone.com/VlAvD
language:
C++ (gcc 8.3)
created:
13 years ago
visibility:
secret

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