std::unique_ptr<T,Deleter>::release

自 C++11 起

pointer release() noexcept; 

自 C++23 起

constexpr pointer release() noexcept;

释放所管理对象的拥有权（如果存在）。

调用后 get() 返回 nullptr。

调用者负责删除该对象。

参数

(无)

返回值

指向所管理对象的指针，或者在没有管理对象的情况下返回 nullptr，即调用前 get() 将返回的值。

示例

#include <memory>
#include <iostream>
#include <cassert>
 
struct Foo {
    Foo() { std::cout << "Foo\n"; }
    ~Foo() { std::cout << "~Foo\n"; }
};
 
int main()
{
    std::cout 
        << "Creating new Foo...\n";
    std::unique_ptr<Foo> up(new Foo());
 
    std::cout 
        << "About to release Foo...\n";
    Foo* fp = up.release();
 
    assert (up.get() == nullptr);
    assert (up == nullptr);
 
    std::cout 
        << "Foo is no longer owned by unique_ptr...\n";
 
    delete fp;
}

结果

Creating new Foo...
Foo
About to release Foo...
Foo is no longer owned by unique_ptr...
~Foo