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  1. #include <iostream>
  2. #include <vector>
  3. #include <string>
  4. #include <algorithm>
  5. #include <iomanip>
  6. #include <type_traits>
  7. #include <typeinfo>
  8. #ifndef _MSC_VER
  9. #   include <cxxabi.h>
  10. #endif
  11. #include <memory>
  12. #include <string>
  13. #include <cstdlib>
  14.  
  15. template <class T>
  16. std::string
  17. type_name()
  18. {
  19.     typedef typename std::remove_reference<T>::type TR;
  20.     std::unique_ptr<char, void(*)(void*)> own
  21.            (
  22. #ifndef _MSC_VER
  23.                 abi::__cxa_demangle(typeid(TR).name(), nullptr,
  24.                                            nullptr, nullptr),
  25. #else
  26.                 nullptr,
  27. #endif
  28.                 std::free
  29.            );
  30.     std::string r = own != nullptr ? own.get() : typeid(TR).name();
  31.     if (std::is_const<TR>::value)
  32.         r += " const";
  33.     if (std::is_volatile<TR>::value)
  34.         r += " volatile";
  35.     if (std::is_lvalue_reference<T>::value)
  36.         r += "&";
  37.     else if (std::is_rvalue_reference<T>::value)
  38.         r += "&&";
  39.     return r;
  40. }
  41.  
  42. template<typename T1, typename T2>
  43. struct my_tuple {
  44. 	T1 x;
  45. 	T2 y;
  46. 	my_tuple(const T1& x, const T2& y) : x(x), y(y) {
  47. 		std::cout << "tuple(" << type_name<const T1&>() << "," << type_name<const T2&>() << ")" << std::endl;
  48. 	}
  49. 	my_tuple(my_tuple<T1,T2>&& other) : x(other.x), y(other.y) {
  50. 		std::cout << "tuple(" << type_name<my_tuple<T1,T2>&&>() << ")" << std::endl;
  51. 	}
  52. 	my_tuple(const my_tuple<T1,T2>& other) : x(other.x), y(other.y) {
  53. 		std::cout << "tuple(" << type_name<const my_tuple<T1,T2>&>() << ")" << std::endl;
  54. 	}
  55. 	my_tuple& operator=(my_tuple<T1,T2>&& other) {
  56. 		std::cout << "tuple(" << type_name<my_tuple<T1,T2>&&>() << ")" << std::endl;
  57. 		x = other.x; y = other.y;
  58. 	}
  59. 	my_tuple& operator=(const my_tuple<T1,T2>& other) {
  60. 		std::cout << "tuple(" << type_name<const my_tuple<T1,T2>&>() << ")" << std::endl;
  61. 		x = other.x; y = other.y;
  62. 	}
  63. };
  64.  
  65. template<typename T1, typename T2>
  66. my_tuple<T1&, T2&> my_tie(T1& x, T2& y) {
  67. 	return my_tuple<T1&, T2&>(x,y);
  68. }
  69.  
  70.  
  71. struct Foo {
  72. 	int x, y;
  73.  
  74. 	Foo(int x, int y) : x(x), y(y) {
  75. 		std::cout << "Foo(x,y)" << std::endl;
  76. 	}
  77. 	~Foo() {
  78. 		std::cout << "~Foo()" << std::endl;
  79. 	}
  80.  
  81. 	template<typename T1, typename T2>
  82. 	operator my_tuple<T1, T2>() {
  83. 		std::cout << "tuple conversion" << std::endl;
  84. 		return my_tuple<T1, T2>(x, y);
  85. 	}
  86. };
  87.  
  88. int main()
  89. {
  90. 	int a, b;
  91. 	my_tie(a, b) = Foo(3,4);
  92.  
  93. 	std::cout << a << ", " << b << std::endl;
  94.  
  95. 	return 0;
  96. }
  97.  
Success #stdin #stdout 0s 3432KB
comments (?)
stdin
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Standard input is empty
stdout
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Foo(x,y)
tuple conversion
tuple(int&,int&)
tuple(int&,int&)
tuple(my_tuple<int&, int&>&&)
~Foo()
3, 4
https://ideone.com/NCEP25
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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