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  1. #include <type_traits>
  2. #include <utility>
  3. #include <iostream>
  4.  
  5. template<typename T>
  6. class Foo
  7. {
  8.     T bar;
  9.  
  10.     template<typename R>
  11.     Foo(R&&, typename std::enable_if<!std::is_convertible<R,T>::value>::type * = 0) = delete;
  12. public:    
  13.     template<typename R>
  14.     Foo(R &&bar, typename std::enable_if<std::is_convertible<R,T>::value>::type * = 0)
  15.         : bar(std::forward<R>(bar))
  16.  
  17.     {
  18.         std::cout << "Initialized from rvalue reference: " <<
  19.             std::is_rvalue_reference<decltype(bar)>::value << std::endl;
  20.     }
  21. };
  22.  
  23. int main()
  24. {
  25.     int i;
  26.     Foo<short> a(i);
  27.     Foo<short> b(4);
  28.  
  29.     // Causes "error: use of deleted function ‘Foo<T>::Foo(R&&, typename std::enable_if"
  30.     //Foo<short> c("failed");
  31.  
  32.     return 0;
  33. }
  34.  
Success #stdin #stdout 0s 2896KB
comments (?)
stdin 
Standard input is empty
stdout 
Initialized from rvalue reference: 0
Initialized from rvalue reference: 1
https://ideone.com/oohMdZ
language:
C++14 (gcc 8.3)
created:
12 years ago
visibility:
public

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