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  1. #include <iostream>
  2.  
  3. /**************************************************************************/
  4.  
  5. template<typename T>
  6. void foo(T v) { std::cout << v.key << ": " << __PRETTY_FUNCTION__ << std::endl; }
  7.  
  8. template<typename T>
  9. struct pair {
  10. 	pair(T v)
  11. 		:key("")
  12. 		,val(v)
  13. 	{}
  14. 	pair(const char *k, T v)
  15. 		:key(k)
  16. 		,val(v)
  17. 	{}
  18.  
  19. 	const char *key;
  20. 	T val;
  21. };
  22.  
  23. template<typename T>
  24. auto make_pair(const char *key, T &val) {
  25. 	return pair<T &>{key, val};
  26. }
  27.  
  28. template<typename T>
  29. auto make_pair(const char *key, const T &val) {
  30. 	return pair<const T &>{key, val};
  31. }
  32.  
  33. /**************************************************************************/
  34.  
  35. struct type {
  36. 	int a;
  37. 	int b;
  38.  
  39. 	type()
  40. 		:a{}
  41. 		,b{}
  42. 	{}
  43.  
  44. 	void m0() const {
  45. 		const auto p0 = make_pair("type.a", a);
  46. 		foo(p0);
  47. 	}
  48. 	void m1() {
  49. 		const auto p0 = make_pair("type.b", b);
  50. 		foo(p0);
  51. 	}
  52. };
  53.  
  54. /**************************************************************************/
  55.  
  56. int main() {
  57. 	type t;
  58. 	t.m0();
  59. 	t.m1();
  60.  
  61. 	int c=0;
  62. 	const int d=0;
  63. 	auto p0 = make_pair("b", 33);
  64. 	foo(p0);
  65. 	auto p1 = make_pair("c", c);
  66. 	foo(p1);
  67. 	auto p2 = make_pair("d", d);
  68. 	foo(p2);
  69.  
  70. 	std::cout << "**********************************" << std::endl;
  71. 	int f=0;
  72. 	const int g=0;
  73. 	foo(make_pair("i", 33));
  74. 	foo(make_pair("f", f));
  75. 	foo(make_pair("g", g));
  76. }
  77.  
  78. /**************************************************************************/
  79.  
Success #stdin #stdout 0s 3140KB
comments (?)
stdin 
Standard input is empty
stdout 
type.a: void foo(T) [with T = pair<const int&>]
type.b: void foo(T) [with T = pair<int&>]
b: void foo(T) [with T = pair<const int&>]
c: void foo(T) [with T = pair<int&>]
d: void foo(T) [with T = pair<const int&>]
**********************************
i: void foo(T) [with T = pair<const int&>]
f: void foo(T) [with T = pair<int&>]
g: void foo(T) [with T = pair<const int&>]
https://ideone.com/6vr1Oh
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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