std::unique_ptr<T,Deleter>::swap
| void swap(unique_ptr& other) noexcept; | (since C++11) | 
Swaps the managed objects and associated deleters of *this and another unique_ptr object other.
Parameters
| other | - | another unique_ptrobject to swap the managed object and the deleter with | 
Return value
(none).
Example
#include <iostream>
#include <memory>
 
struct Foo {
    Foo(int _val) : val(_val) { std::cout << "Foo...\n"; }
    ~Foo() { std::cout << "~Foo...\n"; }
    int val;
};
 
int main()
{
    std::unique_ptr<Foo> up1(new Foo(1));
    std::unique_ptr<Foo> up2(new Foo(2));
 
    up1.swap(up2);
 
    std::cout << "up1->val:" << up1->val << std::endl;
    std::cout << "up2->val:" << up2->val << std::endl;
}Output:
Foo... Foo... up1->val:2 up2->val:1 ~Foo... ~Foo...
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