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  1. #include <iostream>
  2.  
  3. template <class T> void swap(T& a, T& b) {
  4.     T tmp(std::move(a));
  5.     std::cout << a->x << "(" << &a <<"), "; //note que aqui imprimo o endereço da variável que não varia
  6.     std::cout << b->x << "(" << &b <<"), ";
  7.     std::cout << tmp->x << "(" << &tmp <<")\n";
  8.     tmp->foo(3); //só para mostrar que funciona e altera tanto a quanto tmp.
  9.     std::cout << a->x << "(" << a <<"), "; //agora imprimo o valor dela que é o ponteiro e ele muda
  10.     std::cout << b->x << "(" << b <<"), ";
  11.     std::cout << tmp->x << "(" << tmp <<")\n";
  12.     a->foo(1); //confirmando que são o mesmo endereço
  13.     std::cout << a->x << "(" << a <<"), ";
  14.     std::cout << b->x << "(" << b <<"), ";
  15.     std::cout << tmp->x << "(" << tmp <<")\n";
  16.     a = std::move(b);   
  17.     std::cout << a->x << "(" << a <<"), ";
  18.     std::cout << b->x << "(" << b <<"), ";
  19.     std::cout << tmp->x << "(" << tmp <<")\n";
  20.     b = std::move(tmp);
  21.     std::cout << a->x << "(" << a <<"), ";
  22.     std::cout << b->x << "(" << b <<"), ";
  23.     std::cout << tmp->x << "(" << tmp <<")\n";
  24. }
  25.  
  26. template <class T> void old_swap(T& a, T& b) {
  27.     T tmp(a);
  28.     std::cout << a->x << "(" << &a <<"), "; //note que aqui imprimo o endereço da variável que não varia
  29.     std::cout << b->x << "(" << &b <<"), ";
  30.     std::cout << tmp->x << "(" << &tmp <<")\n";
  31.     tmp->foo(3); //só para mostrar que funciona e altera tanto a quanto tmp.
  32.     std::cout << a->x << "(" << a <<"), "; //agora imprimo o valor dela que é o ponteiro e ele muda
  33.     std::cout << b->x << "(" << b <<"), ";
  34.     std::cout << tmp->x << "(" << tmp <<")\n";
  35.     a->foo(1); //confirmando que são o mesmo endereço
  36.     std::cout << a->x << "(" << a <<"), ";
  37.     std::cout << b->x << "(" << b <<"), ";
  38.     std::cout << tmp->x << "(" << tmp <<")\n";
  39.     a = b;   
  40.     std::cout << a->x << "(" << a <<"), ";
  41.     std::cout << b->x << "(" << b <<"), ";
  42.     std::cout << tmp->x << "(" << tmp <<")\n";
  43.     b = tmp;
  44.     std::cout << a->x << "(" << a <<"), ";
  45.     std::cout << b->x << "(" << b <<"), ";
  46.     std::cout << tmp->x << "(" << tmp <<")\n";
  47. }
  48.  
  49. class teste {
  50. 	public:
  51.     	int x = 0;
  52. 	    int foo(int x);
  53. };
  54.  
  55. int teste::foo(int x) {
  56. 	return this->x = x;
  57. }
  58.  
  59. int main() {
  60. 	teste* a = new teste();
  61. 	a->foo(1);
  62. 	teste* b = new teste();
  63. 	b->foo(2);
  64. 	swap(a, b);
  65. 	old_swap(a, b);
  66. 	return 0;
  67. }
  68.  
  69.  
Success #stdin #stdout 0s 3276KB
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stdin
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Standard input is empty
stdout
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1(0xbfc92788), 2(0xbfc9278c), 1(0xbfc9274c)
3(0x8cb0008), 2(0x8cb0018), 3(0x8cb0008)
1(0x8cb0008), 2(0x8cb0018), 1(0x8cb0008)
2(0x8cb0018), 2(0x8cb0018), 1(0x8cb0008)
2(0x8cb0018), 1(0x8cb0008), 1(0x8cb0008)
2(0xbfc92788), 1(0xbfc9278c), 2(0xbfc9274c)
3(0x8cb0018), 1(0x8cb0008), 3(0x8cb0018)
1(0x8cb0018), 1(0x8cb0008), 1(0x8cb0018)
1(0x8cb0008), 1(0x8cb0008), 1(0x8cb0018)
1(0x8cb0008), 1(0x8cb0018), 1(0x8cb0018)
https://ideone.com/L3t9Hb
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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