1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
|
// unique_ptr::get vs unique_ptr::release
#include <iostream>
#include <memory>
int main () {
// foo bar p
// --- --- ---
std::unique_ptr<int> foo; // null
std::unique_ptr<int> bar; // null null
int* p = nullptr; // null null null
foo = std::unique_ptr<int>(new int(10)); // (10) null null
bar = std::move(foo); // null (10) null
p = bar.get(); // null (10) (10)
*p = 20; // null (20) (20)
p = nullptr; // null (20) null
foo = std::unique_ptr<int>(new int(30)); // (30) (20) null
p = foo.release(); // null (20) (30)
*p = 40; // null (20) (40)
std::cout << "foo: ";
if (foo) std::cout << *foo << '\n'; else std::cout << "(null)\n";
std::cout << "bar: ";
if (bar) std::cout << *bar << '\n'; else std::cout << "(null)\n";
std::cout << "p: ";
if (p) std::cout << *p << '\n'; else std::cout << "(null)\n";
std::cout << '\n';
delete p; // the program is now responsible of deleting the object pointed to by p
// bar deletes its managed object automatically
return 0;
}
| |