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  1. #include <iostream>
  2. #include <iostream>
  3.  
  4. template<class... T>
  5. struct non_copyable_type {
  6. 	non_copyable_type() = delete;
  7. 	non_copyable_type(const non_copyable_type&) = delete;
  8. 	non_copyable_type(const T&...) {};
  9. };
  10.  
  11. using T1  = non_copyable_type<int>;
  12. using T2  = T1;
  13. using TL1 = non_copyable_type<T1, T2>;
  14.  
  15. using foo_t = non_copyable_type<T1, T2, TL1>;
  16.  
  17. template<class... Args>
  18. void side_effects(Args&&... args) {
  19. 	std::cout << "side effects" << std::endl;
  20. }
  21. template<class... Args>
  22. void second_side_effects(Args&&... args) {
  23. 	std::cout << "second side effects" << std::endl;
  24. }
  25. template<class... Args>
  26. void final_side_effects(Args&&... args) {
  27. 	std::cout << "final side effects" << std::endl;
  28. }
  29.  
  30. struct C {
  31. 	C(const T1& arg_1, const T2& arg_2) {
  32.     		side_effects(arg_1, arg_2);
  33.     		TL1 local_1(arg_1, arg_2);
  34.     		second_side_effects(arg_1, arg_2, local_1);
  35.     		foo_t f(arg_1, arg_2, local_1); // the actual construction
  36.     		final_side_effects(arg_1, arg_2, local_1, f);
  37. 	}
  38. };
  39.  
  40. struct C2 {
  41. 	C2(const T1& arg_1, const T2& arg_2)
  42. 	: C2(arg_1, arg_2
  43.                 ,([](const T1& a, const T2& b){
  44. 	             side_effects(a, b);
  45.                 }(arg_1, arg_2), TL1(arg_1, arg_2))) {}
  46.  
  47. 	C2(const T1& arg_1, const T2& arg_2, TL1&& local_1)
  48. 	: C2(arg_1, arg_2
  49. 	    ,[](const T1& a, const T2& b, TL1& c) -> TL1& {
  50. 	            second_side_effects(a, b, c);
  51. 	            return c;
  52. 	    }(arg_1, arg_2, local_1)) {}
  53.  
  54. 	C2(const T1& arg_1, const T2& arg_2, TL1& local_1)
  55. 	: f(arg_1, arg_2, local_1) {
  56. 	    final_side_effects(arg_1, arg_2, local_1, f);
  57. 	}
  58. private:
  59. 	foo_t f;
  60. };
  61.  
  62. int main() {
  63. 	T1 a(0);
  64. 	T2 b(0);
  65. 	C c1(a, b);
  66. 	C2 c2(a, b);
  67. }
Success #stdin #stdout 0s 4480KB
comments (?)
stdin 
Standard input is empty
stdout 
side effects
second side effects
final side effects
side effects
second side effects
final side effects
https://ideone.com/Viia4O
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
public

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