Re: [boost] [scope_exit] D-style scope(failure) and scope(success) in C++

Subject: Re: [boost] [scope_exit] D-style scope(failure) and scope(success) in C++
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2013-09-27 03:43:27

On Friday 27 September 2013 00:23:08 Emil Dotchevski wrote:
> On Thu, Sep 26, 2013 at 11:37 PM, Andrey Semashev
> 
> <andrey.semashev_at_[hidden]> wrote:
> > On Thursday 26 September 2013 16:24:21 Emil Dotchevski wrote:
> >> On Thu, Sep 26, 2013 at 4:20 PM, Evgeny Panasyuk
> >> 
> >> <evgeny.panasyuk_at_[hidden]> wrote:
> >> > 27.09.2013 3:08, Emil Dotchevski:
> >> >> Perhaps I'm missing something, but if it is a facility that aids the
> >> >> scope_exit library, it should be part of the scope_exit library. Do
> >> >> you feel that it should be part of Boost Exception?
> >> > 
> >> > There are two parts:
> >> > 1. function uncaught_exception_count
> >> > 2. scope(failure) and scope(success) which are built on top of
> >> > uncaught_exception_count
> >> > 
> >> > I have in mind two approaches:
> >> > a) Add both into Boost.ScopeExit
> >> > or
> >> > b) As a first step add uncaught_exception_count into Boost.Exception -
> >> > as
> >> > it is closely related to it's theme. And then
> >> > scope(failure)/scope(success) will go into Boost.ScopeExit.
> >> 
> >> Is there a use case for uncaught_exception_count other than to
> >> implement D-style scope-exit/-failure?
> > 
> > In Boost.Log, I use it to implement my own guard objects which must
> > perform
> > some finalizing work at destructor. With uncaught_exception_count I am
> > able to detect whether the destructor is invoked as a result of an
> > exception and cancel the work.
> 
> Isn't this the same use case as scope-failure?

The guard object in Boost.Log is not a scope guard but is a temporary object. 
But the use of uncaught_exception_count is very similar.

I cannot reuse scope_exit(success) if you imply that.