Re: [boost] [TypeIndex] Peer review period for library acceptance begins, ending Thurs 21st Nov

Subject: Re: [boost] [TypeIndex] Peer review period for library acceptance begins, ending Thurs 21st Nov
From: Antony Polukhin (antoshkka_at_[hidden])
Date: 2013-11-14 00:26:13

2013/11/14 Steven Watanabe <watanabesj_at_[hidden]>

> AMDG
>
> On 11/12/2013 11:34 AM, Niall Douglas wrote:
> > Boost community feedback is requested for the formal peer review of
> > the TypeIndex library by Antony Polukhin. Feedback requested
> > includes:
> >
> > 1. Should this library be accepted into Boost?
> >
>
> No.  This library should not be accepted into Boost
> in its current form.
>
> type_info.hpp:139:
>         return static_cast<const boost::type_info&>(typeid(type));
>
> This is undefined behavior, and there is no
> way to make it correct.
>

This is a necessary evil and it is harmless:
* all the methods of std::type_info (except destructor) are non virtual, so
for example calls to name() will call boost::type_info::name()
* it is *undefined* which destructor (std::type_info or boost::type_info)
will be called *but*:
  * boost::type_info contains no members, it's size must be equal to the
size of std::type_info, so no harm if boost::type_info destructor won't be
called
  * destructor of std::type_info will be called anyway

I can add assert to tests to ensure that sizeof(std::type_info) ==
sizeof(boost::type_info).

-- 
Best regards,
Antony Polukhin