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  1. #include <iostream>
  2. #include <iomanip>
  3. #include <type_traits>
  4.  
  5. struct move_not_copy { move_not_copy(move_not_copy &&); };
  6.  
  7. template<typename T>
  8. struct has_move_constructor {
  9. 	struct helper : public move_not_copy,  public T {
  10. 	};
  11. 	constexpr static bool value = std::is_constructible<helper, typename std::add_rvalue_reference<helper>::type> ::value;
  12. 	constexpr operator bool () const { return value; }
  13. };
  14.  
  15. struct T0 {
  16. 	void operator=(T0&&) {}
  17. };
  18. struct Copy {
  19.    Copy( const Copy& );
  20. };
  21. struct MoveOnly {
  22.    MoveOnly( MoveOnly&& );
  23. };
  24. struct Both {
  25.    Both( const Both& );
  26.    Both( Both&& );
  27. };
  28. struct CopyWithDeletedMove {
  29.    CopyWithDeletedMove( const CopyWithDeletedMove& );
  30.    CopyWithDeletedMove( CopyWithDeletedMove&& ) = delete;
  31. };
  32.  
  33. template<typename T>
  34. void provide_a_report_impl(const char *type_name) {
  35. 	std::cout << std::setw(20) << type_name
  36. 		<< "  is_copy_constructible " << std::is_constructible<T, typename std::add_lvalue_reference<T>::type>()
  37. 		<< "  is_move_constructible " << std::is_constructible<T, typename std::add_rvalue_reference<T>::type>()
  38. 		<< "  has_move_constructor " << has_move_constructor<T>::value
  39. 		<< std::endl;
  40. };
  41. #define REPORT_ON_ISHAS_MOVE_CONSTRUCTOR(T) provide_a_report_impl<T>(#T)
  42.  
  43. int main()
  44. {
  45.    REPORT_ON_ISHAS_MOVE_CONSTRUCTOR(Copy);
  46.    REPORT_ON_ISHAS_MOVE_CONSTRUCTOR(MoveOnly);
  47.    REPORT_ON_ISHAS_MOVE_CONSTRUCTOR(Both);
  48.    REPORT_ON_ISHAS_MOVE_CONSTRUCTOR(CopyWithDeletedMove);
  49. }
Success #stdin #stdout 0s 3300KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
                Copy  is_copy_constructible 1  is_move_constructible 1  has_move_constructor 1
            MoveOnly  is_copy_constructible 0  is_move_constructible 1  has_move_constructor 1
                Both  is_copy_constructible 1  is_move_constructible 1  has_move_constructor 1
 CopyWithDeletedMove  is_copy_constructible 1  is_move_constructible 0  has_move_constructor 0
https://ideone.com/CbmUxG
language:
C++14 (gcc 8.3)
created:
11 years ago
visibility:
public

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