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  1. #include <iostream>
  2. #include <typeinfo>
  3.  
  4. struct X { };
  5.  
  6. template<typename T> 
  7. struct aux
  8. {
  9.   void operator()(T&&) const { std::cout << 1 << std::endl; }  
  10. };
  11.  
  12. template<typename T> 
  13. struct aux<const T>
  14. {
  15.   void operator()(const T&& t) const { aux<T&>()(t); }  
  16. };
  17.  
  18. template<typename T> 
  19. struct aux<T&>
  20. {
  21.   void operator()(const T&) const { std::cout << 2 << std::endl; }  
  22. };
  23.  
  24. template<typename T> void g(T&& t)
  25. { 
  26.     aux<T>()(std::forward<T>(t)); 
  27. }
  28.  
  29. X foo() { return X(); }
  30. const X bar() { return X(); }
  31.  
  32. int main()
  33. {
  34.     X x1;
  35.     g(std::move(x1)); // 1
  36.     g(foo());         // 1
  37.     g(x1);            // 2
  38.     g(bar());         // 2
  39.  
  40.     const X x2;
  41.     g(std::move(x2)); // 2
  42.     g(x2);            // 2
  43.  
  44. }
Success #stdin #stdout 0s 3340KB
comments (?)
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Standard input is empty
stdout 
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https://ideone.com/U2ElNj
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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