Re: [boost] try... catch... finally?

From: Hans Larsen (hans_at_[hidden])
Date: 2007-04-04 22:02:50

Hey guys.  Very interesting this problem is and the proposed  
solutions leads one to another :)

Problem underlined below.

On 4-Apr-07, at 6:27 PM, Steven Watanabe wrote:

> Alexander Nasonov <alnsn <at> yandex.ru> writes:
>
>> I'm very impressed how you wrote it off the top of your head :->
>
> I didn't.  I've been toying with it for a
> couple of days.
>
>> But it's definitely too much magic. Though, it made me think of
>> another magic: study alloca implementations and replace a global
>> variable with something like
>>
>> <snip>
>
> Why do you need this magic?
>
> BOOST_SCOPE_EXIT( (hello)(world) ) // line 1
>    /* Expands to:
>       struct args_line1_t { std::string &hello, &world; }  
> args_line1 = {
>           hello, world
>       };
>       struct scope_exit_line1 {
>           args_line1_t* m_args;
>           ~scope_exit() {
>               doit(p->hello, p->world);
>            }
>            static void doit(std::string& hello, std::string& world)
>    */
>    {
>        // scope(exit) code
>    }
>    BOOST_SCOPE_EXIT_END // line 5
>    /*
>       } scope_exit_line5 = { &args_line1 };

How do you know that it is args_line1?  You cannot use __LINE__,  
since it is == 5.

Hans

>    */
>
> In Christ,
> Steven Watanabe
>
>
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