如何从成员析构函数中捕获异常 [英] How to catch exception from member destructor

问题描述

我想知道是否（以及如何）捕获在成员析构函数中引发的异常。示例：

I wonder whether (and how) it's possible to catch an exception thrown in a member destructor. Example:

#include <exception>

class A
{
public:
    ~A() {
        throw std::exception("I give up!");
    }
};

class B
{
    A _a;
public:
    ~B() {
        // How to catch exceptions from member destructors?
    }
};

推荐答案

是的，您可以使用 function-try-block：

class B
{
    A _a;
public:
    ~B() try {
        // destructor body
    }
    catch (const std::exception& e)
    {
        // do (limited) stuff
    }
};

但是，您不能在这种例外情况下做得太多。该标准指定您不能访问 B 对象的非静态数据成员或基类。

However, you cannot really do much with such an exception. The standard specifies that you cannot access non-static data members or base classes of the B object.

此外，您无法将异常静音。与其他函数不同，一旦析构函数（或构造函数）的 function-try-block 处理程序执行完毕，该隐式将隐式重新抛出。

Also, you cannot silence the exception. Unlike with other functions, the exception will be re-thrown implicitly once the function-try-block handler of a destructor (or constructor) finishes execution.

总而言之，析构函数实际上不应引发异常。

All in all, destructors should really not throw exceptions.

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