Re: [boost] std::exception -- Re: Re: Re: Re: Re:AttemptingresolutionofThreads&ExceptionsIssue

From: Victor A. Wagner, Jr. (vawjr_at_[hidden])
Date: 2002-08-15 03:27:35

Thank you for the example.  I guess I hadn't paid as close attention to the 
last paragraph of 14.3.1 of Stroustrup 3rd ed. as I thought.
At Wednesday 2002/08/14 10:53, you wrote:
>From: "Victor A. Wagner, Jr." <vawjr_at_[hidden]>
> > >
> > >Well, I am not a compiler writer, but it seems to me that to implement
> > >"throw;" and "catch", the compiler already needs a way to copy the
> > >exception, complete with its original type. :-)
> >
> > I don't see that at all.  The catch() clause specifies the type it's
> > expecting and it will be copied and sliced if need be to match.
>
>Quiz: what does this program do?
>
>#include <iostream>
>
>struct X
>{
>};
>
>struct Y: public X
>{
>};
>
>void f()
>{
>     try
>     {
>         throw Y();
>     }
>     catch(X)
>     {
// an exception will be caught here.
>        throw;
// an exception of type Y will be thrown.
>     }
>}
>
>int main()
>{
>     try
>     {
>         f();
>     }
>     catch(Y)
>     {
// an exception will be caught here.
>         std::cout << "Caught an Y!\n";
>     }
>}
>
>
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Victor A. Wagner Jr.      http://rudbek.com
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