Re: [boost] The noexcept Specifier & Block

Subject: Re: [boost] The noexcept Specifier & Block
From: Alexander Terekhov (terekhov_at_[hidden])
Date: 2009-04-18 09:19:25

Peter Dimov wrote:
> 
> Alexander Terekhov:
> 
> > Avoiding unwinding for unexpected exceptions, for example.
> 
> The reason the standard specifies calling unexpected() at the exception spec
> point is conceptually sound (but practically not that useful). Consider
> 
> void f()
> {
>     throw X();
> }
> 
> void g() throw(Y)
> {
>     f();
> }
> 
> void h() throw(Z)
> {
>     g();
> }
> 
> If unexpected() is always invoked at the throw point, there is no way for an
> exception to escape this call stack. If it's invoked at the exception
> specification points, it can, in principle, first throw a Y, then a Z. The
> primary purpose of unexpected(), as originally envisaged (I presume), is
> exception translation.

But exception translation can be done much more sensibly without
unexpected().

void f()
{
    throw X();
}

void g() throw(Y)
{
    translate_any_exception_to<Y>(f);
}

void h() throw(Z)
{
    translate_exception<Y, Z>(g);
}

No?

regards,
alexander.