Re: [boost] Re: Re: Re: Re: partial<> proposal

From: Fernando Cacciola \(Home\) (fernando_cacciola_at_[hidden])
Date: 2003-02-24 16:57:13

----- Original Message -----
From: "Philippe A. Bouchard" <philippeb_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Monday, February 24, 2003 6:31 PM
Subject: [boost] Re: Re: Re: Re: partial<> proposal

> Fernando Cacciola wrote:
>
> [...]
>
> >> Given the fact optional<>::m_storage is aligned like a bool...:
> >>
> > It is not aligned like a bool...
>
> Well it depends on the platform but if sizeof(bool) == sizeof(int) on
Intel,

^^^^^^^
Were does this 'int' comes from?

> m_storage will be aligned to the next word boundary i.e. aligned like an
> integer.
>
Anyway, you just said that it depends on the platform, so I wouldn't say
that m_storage *is*
aligned like bool, at most, it could be.

> >> - Maybe aligned_storage<> should always destruct its object.  It
> >> would be the user's responsability to construct the object before
> >> its destruction, otherwise the result would be undefined.
> >>
> > Why would this be useful?
>
> I don't know, it is just another alternative that I personally prefer.
>
Why do you prefer this?

> >> - Maybe we could create 2 separate type lists if optional<> is used
> >> many times in the same object, gathering m_initialized types and
> >> m_storage in separate lists:
> >>
> > What for ?
>
> I think bool arrays use bitfields
>
Which bool arrays?

bool x[..] ;

dont't.

std::vector<bool>

maybe, but are less efficient in that case.

Fernando Cacciola