在C ++中通过指针捕获异常 [英] catch exception by pointer in C++

问题描述

我发现有三种方法可以捕获异常，有什么区别？

I found that there are three ways to catch an exception, what are the differences?

1）按值捕获;

2）catch by reference;

2) catch by reference;

3）通过指针捕获;

3) catch by pointer;

知道catch by value会调用对象的两个副本，catch通过引用将调用一个。那么如何用指针捕捉呢？何时使用catch by指针？除了抛出一个对象，我可以抛出一个指针指向这样的对象吗？

I only know that catch by value will invoke two copies of the object, catch by reference will invoke one. So how about catch by pointer? When to use catch by pointer? In addition to throw an object, can I throw a pointer to an object like this?

class A {}

void f() {

  A *p = new A();
        throw p;


}

推荐答案

推荐的方法是按值引用和按引用捕获。

您的示例代码会抛出一个指针，

Your example code throws a pointer, which is a bad idea since you would have to manage memory at the catch site.

如果你真的觉得你应该抛出一个指针，使用一个聪明的指针，如 shared_ptr 。

If you really feel you should throw a pointer, use a smart pointer such as shared_ptr.

无论如何，Herb Sutter和Alexei Alexandrescu在他的C ++编码标准书中解释得很好。

Anyway, Herb Sutter and Alexei Alexandrescu explain that really well in their C++ Coding Standards book which I paraphrased.

请参阅 C ++编码标准：按值，按参考。

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