std::unique_ptr::reset

来自cppreference.com
< cpp‎ | memory‎ | unique ptr

 
 
 
 
 
void reset( pointer ptr = pointer() );
(C++11 起)

Replaces the managed object.

Given current_ptr, the pointer that was managed by *this, performs the following actions, in this order:

  1. Saves a copy of the current pointer old_ptr = current_ptr
  2. Overwrites the current pointer with the argument current_ptr = ptr
  3. If the old pointer was non-empty, deletes the previously managed object if(old_ptr != nullptr) get_deleter()(old_ptr).

目录

[编辑] 参数

ptr - pointer to a new object to manage

[编辑] 返回值

(无)
原文:
(none)
文本通过谷歌翻译机器翻译。
你可以帮忙校正和验证翻译。点击此处查看指示。

[编辑] 注释

To replace the managed object while supplying a new deleter as well, move assignment operator may be used.

A test for self-reset, i.e. whether ptr points to an object already managed by *this, is not performed, except where provided as a compiler extension or as a debugging assert. Note that code such as p.reset(p.release()) does not involve self-reset, only code like p.reset(p.get()) does.

[编辑] 示例

#include <iostream>
#include <memory>
 
struct Foo {
    Foo() { std::cout << "Foo...\n"; }
    ~Foo() { std::cout << "~Foo...\n"; }
};
 
struct D {
    void operator() (Foo* p) {
        std::cout << "Calling delete for Foo object... \n";
        delete p;
    }
};
 
int main()
{
    std::cout << "Creating new Foo...\n";
    std::unique_ptr<Foo, D> up(new Foo(), D());  // up owns the Foo pointer (deleter D)
 
    std::cout << "Replace owned Foo with a new Foo...\n";
    up.reset(new Foo());  // calls deleter for the old one
 
    std::cout << "Release and delete the owned Foo...\n";
    up.reset(nullptr);      
}

输出:

Creating new Foo...
Foo...
Replace owned Foo with a new Foo...
Foo...
Calling delete for Foo object...
~Foo...
Release and delete the owned Foo...
Calling delete for Foo object...
~Foo...

[编辑] 另请参阅

返回一个指向被管理对象的指针,并释放所有权
(公开成员函数) [编辑]