抛出的catch（...）抛出的值或引用 [英] Does a throw in catch(...) throw by value or by reference

问题描述

我的老板回答了这个问题为什么... （三分）在catch块中存在？非常优雅。

My boss answered this question why ... (three points) in catch block is exist? quite elegantly.

但它使我想到了一些东西（希望弥补我以前的坏问题） ，

But it's made me think of something (and hopefully makes up for my previous bad question), does

catch(...){
    throw;
}

通过值重新抛出捕获的异常

rethrow the caught exception by value (i.e. a deep copy is taken), or by reference?

推荐答案

标准说：

没有操作数的throw-expression会重新抛出当前处理的异常。例外被重新激活与现有的临时;没有新的临时异常对象被创建。

A throw-expression with no operand rethrows the currently handled exception. The exception is reactivated with the existing temporary; no new temporary exception object is created.

- ISO / IEC 14882： 8

换句话说，它只是使用原始异常对象继续异常传播。我想这是类似于你的意思是通过参考。

In other words, it simply continues the exception propagation with the original exception object. I suppose this is analogous to what you mean by "by reference".

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