释放给调用方返回的存储指针的所有权，并将存储的指针值设置为nullptr。
属性值/返回值
返回存储的指针。
备注
使用 release接管unique_ptr存储的原始指针的所有权。 调用方负责返回的指针的删除。 unique-ptr设置为空的默认构造状态。 在调用到release后，您可以将兼容类型的另一个指针分配到unique_ptr。
示例
此示例显示发布的调用方如何负责返回的对象：
点击查看代码
#include<iostream>
#include<memory>
struct Sample
{int content_;Sample(int content) :content_(content) {std::cout << "Constructing Sample(" << content_ << ")" << std::endl;}~Sample() {std::cout << "Deleting Sample(" << content_ << ")" << std::endl;}
};
void ReleaseUniquePointer() {//Use make_unique function when possible.auto up1 = std::make_unique<Sample>(3);auto up2 = std::make_unique<Sample>(42);//Take over ownership from the unique_ptr up2 by using releaseauto ptr = up2.release();if (up2) {//This statement does not execute,because up2 is empty.std::cout << "up2 is not empty." << std::endl;}// We are now respnsible for deletion of ptr.delete ptr;//up1 deletes its stored pointer when it goes out of scope.
}
int main() {ReleaseUniquePointer();
}
https://learn.microsoft.com/zh-cn/previous-versions/ee475597(v=vs.120)
