我有一个“经理”类,它必须在成员被销毁后做一些清理工作:
class Manager
{
Member a, b;
~Manager()
{
// this code will be executed BEFORE the a and b destructors
important_cleanup();
}
};
这里的问题是 important_cleanup()
使我的变量 a
和 b
无效,因此它们的析构函数失败。
是否有解决该问题的好方法?
PS 我知道我可以定义某种 clenup 成员,并使其成为 Manager
的第一个创建成员,但这看起来很丑陋并且使事情变得井井有条-依赖...
最佳答案
依赖销毁顺序确实不容易出错,假设您还发表了一条评论,说明成员顺序对特定成员很重要。将其放入语言中是有原因的,因此使用起来完全没问题。
就是说,如果您不放心依赖它,destructors of members are called before those of the base classes,所以你可以使用一个基类来做到这一点:
class ManagerCleanup {
public:
~ManagerCleanup() {
important_cleanup();
}
private:
some_native_resource resource;
};
// Might as well inherit privately
class Manager : private ManagerCleanup
{
Member a, b;
};
请注意,如果您包装资源,它会更加地道:
// Note: this could probably be a std::unique_ptr. std::unique_ptr can
// manage arbitrary resources, not just pointers.
class ItemRequiringCleanup {
public:
// Ensure you implement/disable copy/move operations appropriately
~ItemRequiringCleanup() {
important_cleanup();
}
private:
some_native_resource resource;
};
class ManagerCleanup {
private: // or protected:
ItemRequiringCleanup resource;
};
// Might as well inherit privately
class Manager : private ManagerCleanup
{
Member a, b;
};
关于c++ - 如何在*成员被销毁后*在析构函数中执行一些代码,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/50494286/