Re: throw()

From:

Nick Keighley <nick_keighley_nospam@hotmail.com>

Newsgroups:

comp.lang.c++

Date:

Tue, 29 Apr 2008 07:00:29 -0700 (PDT)

Message-ID:

<e3a96100-ba06-46f5-bf33-1f0df4afa115@p25g2000hsf.googlegroups.com>

On 29 Apr, 14:25, "Samant.Tru...@gmail.com" <Samant.Tru...@gmail.com>
wrote:

On Apr 29, 5:49 pm, Roland Mueller <roland.em0...@googlemail.com>
wrote:

On Apr 29, 3:32 pm, "Samant.Tru...@gmail.com"
<Samant.Tru...@gmail.com> wrote:

bool CControlDrvInstance::IsRebootRequired() const throw()
In this code what is throw() do? I just have slight knowledge that =

a exception handler but how does it work.

Empty throw() declares that the function is not expected to throw any
exceptions. If it nevertheless does, abort() is called and the
exception cannot be catched from client code using the function.

If I have this in my code do I need to include "try catch" block? I=

yes why?

Ohhh ok. So it is like "on error resume next" in VB right?

what is? I suppose a try-catch is. But the exception declaration
above (the throw() bit) isn't. The ED is saying this function
does not throw any exceptions.

Is that mean we cannot have "try catch" in that function?

IsBootRequired() can have a try-catch (though probably not a
good idea).

bool CControlDrvInstance::IsRebootRequired() const throw()
{
    try {
        if (subDevice1.IsRebootRequired() ||
subDevice1.IsRebootRequired())
            return true;
        else
            return false;
    }
    catch (...)
    {
         //oops something threw!
         return true; // just in case...
    }
}

so it doesn't throw. More likely is it is just too simple to
throw. Or has been carefully proven not to throw.

bool CControlDrvInstance::IsRebootRequired() const throw()
{
    return true;
}

void my_code (CControlDrvInstance& cdi)
{
    if (cdi.IsRebootRequired())
        cdi.Boot();
}

if neither of the function calls throw then my_code()
won't throw either.

--
Nick Keighley