在c ++中尝试/最终实现 [英] try/finally implementation in c++
问题描述
大家好
这是我用C ++实现try / finally
构造的一个小小的编程挑战。我已经完成了几个实现，但它们都有
限制。主要尝试使用析构函数执行
finally码。然而，这有一个很大的局限性，即析构函数
无法看到局部变量。另一种解决这个问题的方法
如下：
{
MyBaseException * processedException = NULL;
尝试
{
< try code>
}
catch（MyBaseException& e）
{
processedException = e.Clone（）;
}
< finally code>
if（processedException）
throw * processedException;
}
但是，这种方法有限制，它只适用于特定的
类异常对象。
我很想看到其他想法
问候
Alex
Hi all
Its one of my little pragramming challenges to implement a try/finally
construct in C++. I have done several implementations but they all have
limitations. Have tried mostly using a destructor to execute the
"finally" code. However this has the big limitation that the destructor
cannot see local variables. Another approach that solves this problem
is the following:
{
MyBaseException* handledException = NULL;
try
{
<try code>
}
catch(MyBaseException& e)
{
handledException = e.Clone();
}
<finally code>
if (handledException)
throw *handledException;
}
However, this method has the limitation that it works only for specific
classes of exception objects.
I''m curious to see other ideas
Regards
Alex
推荐答案
avasilev写道：
avasilev wrote:
大家好
这是我在C ++中实现try / finally
构造的一个小小的编程挑战。我已经完成了几个实现，但它们都有限制。主要尝试使用析构函数来执行
finally。码。然而，这有一个很大的限制，即析构函数无法看到局部变量。
Hi all
Its one of my little pragramming challenges to implement a try/finally
construct in C++. I have done several implementations but they all have
limitations. Have tried mostly using a destructor to execute the
"finally" code. However this has the big limitation that the destructor
cannot see local variables.
不是我推荐它但是......
如果析构函数是包含那些
变量的本地结构的一部分，那就可以了。
需要考虑的事情。
Not that I am recommending it but...
It could if the destructor was part of a local struct containing those
variables.
Something to think about.
avasilev写道：
avasilev wrote:
我很想看到其他想法
news：comp.lang.c ++。moderated在这个主题的
上有一个巨大的多线程对话。有人建议在
语言中添加一个''finally''关键字。
我发现有人认为C ++可以学习一些关于清理的知识来自Java的
非常令人不安。
大多数消息来源推荐RAII用于C ++的异常中立清理机制。
-
Phlip
http：//www.greencheese .org / ZeekLand < - 不是博客!!!
news:comp.lang.c++.moderated has a humongous multi-thread conversation on
this topic. Someone has suggested adding a ''finally'' keyword to the
language.
I find the idea that anyone thinks C++ can learn something about cleanup
from Java very disturbing.
Most sources recommend RAII for C++''s exception-neutral cleanup mechanism.
--
Phlip
http://www.greencheese.org/ZeekLand <-- NOT a blog!!!
* avasilev写道，2006年3月31日22:58：
* avasilev wrote, on 31/03/2006 22:58:
我很想看到其他想法
I''m curious to see other ideas
忽略自然语言文本（如果你不懂挪威语）和
专注于链接&代码：
< url：http：//utvikling.com/cppfaq/04/04/02/index.html>。
-
答：因为它弄乱了人们通常阅读文字的顺序。
问：为什么这么糟糕？
A：热门发布。
问：usenet和电子邮件中最烦人的事情是什么？
Disregard the natural language text (if you don''t know Norwegian) and
concentrate on links & code:
<url: http://utvikling.com/cppfaq/04/04/02/index.html>.
--
A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?
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