Re: [boost] Policy proposal: All user-visible exceptions should be thrown through BOOST_THROW_EXCEPTION [was RE: Boost and exceptions]

Subject: Re: [boost] Policy proposal: All user-visible exceptions should be thrown through BOOST_THROW_EXCEPTION [was RE: Boost and exceptions]
From: Jeffrey Lee Hellrung, Jr. (jeffrey.hellrung_at_[hidden])
Date: 2012-06-25 19:56:04

On Mon, Jun 25, 2012 at 4:49 PM, Emil Dotchevski
<emildotchevski_at_[hidden]>wrote:

> On Mon, Jun 25, 2012 at 2:13 PM, Jeffrey Lee Hellrung, Jr. <
> jeffrey.hellrung_at_[hidden]> wrote:
>
> > On Mon, Jun 25, 2012 at 2:32 PM, Pete Bartlett <pete_at_[hidden]>
> > wrote:
> >
> > > > On 06/22/2012 02:23 PM, Stewart, Robert wrote:
> > >
> > > >There is no Boost policy that requires Boost.Exception support.  If
> you
> > > think there should be, >then lobby for it.
> > >
> > > This thread has pushed me in the direction that this is the way to go.
> > Here
> > > are some specific policy change proposals:
> > >
> > > 1) Mandate that all throws should be through BOOST_THROW_EXCEPTION and
> > > enforce through Boost.Inspect. or:
> > >
> > 2) Strongly suggest in developer documentation that they should be
> through
> > > BOOST_THROW_EXCEPTION but drop short of mandating. or:
> > > 3) Better document and formalize existing practice (that user-visible
> > > exceptions should derive from std::exception, and that a developer may
> > use
> > > BOOST_THROW_EXCEPTION and boost::throw_exception and may respect
> > > BOOST_NO_EXCEPTIONS, but isn't obliged to do so)
> > >
> > [...]
> >
> > Regarding (1) and (2), I think one should have the option to simply use
> > boost::throw_exception. The additional file/function/line info may not be
> > very useful within a templated implementation detail, and, in any case,
> > such info is likely only useful/usable in a debugging context.
> >
>
> boost::exception stores the BOOST_THROW_EXCEPTION information in a custom,
> more efficient way than other data. The only overhead is the potential
> bloat from BOOST_CURRENT_FUNCTION, which now can be controlled (see ticket
> #6450.)
>
> At least in my experience BOOST_THROW_EXCEPTION is very helpful in
> combination with boost::diagnostic_information. In my development
> environment, I can double-click the message to go to the location of the
> throw, which makes it easy to set a break point and run again to see the
> context in which the unexpected exception happens.
>

Hmmm...should these details be added to the BOOST_THROW_EXCEPTION
documentation? It's not at all clear from the documentation what overhead
BOOST_THROW_EXCEPTION brings relative to simply boost::throw_exception.

- Jeff