英文:

Address of unique_ptr doesn't change even after std::move

问题

I am exploring unique_ptr . I am getting wrong answer than expected , Can anyone help me to find what exactly went wrong here in code .
I am using WSL(windows system for linux) on windows machine .

#include <iostream>
#include <memory>
using namespace std;

int main()
{
    auto revenu_ptr{make_unique<double>(1234.64)};
    cout << "Revenue ptr---------" << endl;
    cout << "Original " << &revenu_ptr << " " << *revenu_ptr << endl;

    auto revenue_ptr_move = std::move(revenu_ptr);
    cout << "After Move " << &revenu_ptr << endl;
    cout << "Revenue_ptr_move---------" << endl;
    cout << "Moved Adderess " << &revenue_ptr_move << endl;
    cout << "Moved Value " << *revenue_ptr_move << endl;
}

Expected Output :
Revenue ptr---------
Original 0x7ffd442e9618 1234.64
After Move 0x0
Revenue_ptr_move---------
Moved Adderess 0x7ffd442e9618
Moved Value 1234.64

But I am getting this wrong output , after move operation adderss should become zero but it is pointing at same memory location . and new adderess is there in revenue_ptr_move

Revenue ptr---------
Original 0x7ffd442e9618 1234.64
After Move 0x7ffd442e9618
Revenue_ptr_move---------
Moved Adderess 0x7ffd442e9620
Moved Value 1234.64

<details>
<summary>英文:</summary>

I am exploring unique_ptr . I am getting wrong answer than expected , Can anyone help me to find what exactly went wrong here in code .
I am using WSL(windows system for linux) on windows machine .

#include <iostream>
#include <memory>
using namespace std;

int main()
{
auto revenu_ptr{make_unique<double>(1234.64)};
cout << "Revenue ptr---------" << endl;
cout << "Original " << &revenu_ptr << " " << *revenu_ptr<< endl;

auto revenue_ptr_move = std::move(revenu_ptr);
cout << "After Move " << &revenu_ptr << endl;
cout << "Revenue_ptr_move---------" << endl;
cout << "Moved Adderess " << &revenue_ptr_move<< endl;
cout << "Moved Value " << *revenue_ptr_move << endl;

}

Expected Output :
Revenue ptr---------
Original 0x7ffd442e9618 1234.64
After Move 0x0
Revenue_ptr_move---------
Moved Adderess 0x7ffd442e9618
Moved Value 1234.64

But I am getting this wrong output , after move operation adderss should become zero but it is pointing at same memory location . and new adderess is there in revenue_ptr_move 

Revenue ptr---------
Original 0x7ffd442e9618 1234.64
After Move 0x7ffd442e9618
Revenue_ptr_move---------
Moved Adderess 0x7ffd442e9620
Moved Value 1234.64

</details>


# 答案1
**得分**: 2

`&amp;revenu_ptr`是唯一指针对象的地址。

`*revenu_ptr`是指向的数据。

`revenu_ptr.get()`是唯一指针对象的值。

你似乎把`&amp;revenu_ptr`和`revenu_ptr.get()`混淆了。

这并不是一个罕见的问题。指针的“指针地址”与“指针值”不同。而指针值是*一个地址*的事实使得混淆更加复杂！

此外，指针所指的值与指针本身的值也不同。

指针有一个值，是一个地址。

指针的地址是一个地址。

指针指向的值有一个地址，这个地址就是指针的值。


    [&amp;ptr] -&gt; [ptr.get()] -&gt; [7]

这里有一个（唯一的）指针，它指向值7。

它有一个地址——存储它本身的地方。它有一个值，是它指向的值7的地址。它指向的值是一个整数，值为7。

<details>
<summary>英文:</summary>

`&amp;revenu_ptr` is the address of the unique ptr object.

`*revenu_ptr` is the data pointed to.

`revenu_ptr.get()` is the value of the unique ptr object.

You appear to be confusing `&amp;revenu_ptr` with `revenu_ptr.get()`.

This isn&#39;t a rare problem.  The &quot;address of a pointer&quot; is not the same as the &quot;value of a pointer&quot;.  And the fact that the value of a pointer is *an address* adds to the confusion!

On top of that, the value the pointer POINTS AT is different than the value the pointer HAS.

The pointer has a value that is an address.

The pointer&#39;s address is an address.

The pointer&#39;s pointed-to value has an address, which is the pointer&#39;s value.


    [&amp;ptr] -&gt; [ptr.get()] -&gt; [7]

here we have a (unique) ptr which is pointing at the value 7.

It has an address -- where itself is stored.  It has a value, which is the address of the value 7 it points at.  And it has a pointed-to value, which is an integer with the value 7.


</details>