Re: [boost] [1.37.0][serialization] Assertion failed at libs/serialization/src/extended_type_info.cpp:92

Subject: Re: [boost] [1.37.0][serialization] Assertion failed at libs/serialization/src/extended_type_info.cpp:92
From: Hartmut Kaiser (hartmut.kaiser_at_[hidden])
Date: 2008-10-21 11:59:26

> > Actually, to be concise, you're invoking undefined behavior. The
> Standard
> > doesn't guarantee any execution order of operations in this context.
> The
> > only thing which is guaranteed is, that the operation executed by
> erase()
> > uses the initial value and afterwards start has been incremented
> (well,
> > whatever happens if you increment an iterator after erasing the
> element it's
> > pointing to).
> >
> 
> I still disagree; start++ produces a side effect (std 1.9.7, emphasis
> mine):
> 
>   "Accessing an object designated by a volatile lvalue (3.10),
> *modifying an object* [...]
>   are all side effects, which are changes in the state of the execution
> environment.[...]
>   At certain specified points in the execution sequence called sequence
> points, all side
>   effects of previous evaluations shall be complete and no side effects
> of subsequent
>   evaluations shall have taken place."
> 
> and as such, it must have taken place by the time the function erase is
> invoked (std 1.9.17):
> 
>   "When calling a function (whether or not the function is inline),
> there is a sequence point
>   after the evaluation of all function arguments (if any) which takes
> place before execution
>   of any expressions or statements in the function body .[...]"

Ok, I'm wrong. But I remember at least one problem in the past I have had
exactly because of this. But that just might have been a non-conforming
compiler playing games on me.

Thanks for the explanations.
Regards Hartmut