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  1. #include <functional>
  2. #include <string>
  3. #include <iostream>
  4.  
  5. struct Guy ;
  6.  
  7. struct Girl
  8. {
  9.     Girl( Guy& g ) : boyfriend(g) {}
  10.     std::reference_wrapper<Guy> boyfriend ;
  11. };
  12.  
  13. struct Guy
  14. {
  15.     const std::string name ;
  16.   // ...
  17. };
  18.  
  19. int main()
  20. {
  21.     Guy a { "a" };
  22.  
  23.     Girl b(a) ;
  24.     std::cout << b.boyfriend.get().name << '\n' ;
  25.  
  26.     Guy c { "c" } ;
  27.     b.boyfriend = c ;
  28.     std::cout << b.boyfriend.get().name << '\n' ;
  29.  
  30.     Guy no_one { "no one" };
  31.     b.boyfriend = no_one ;
  32.     std::cout << b.boyfriend.get().name << '\n' ;
  33. }
  34.  
Success #stdin #stdout 0s 3028KB
comments (?)
stdin 
Standard input is empty
stdout 
a
c
no one
https://ideone.com/1QKNpu
language:
C++14 (gcc 8.3)
created:
12 years ago
visibility:
public

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