Re: [boost] [integer] Promotion of endian library code from vault

From: Scott McMurray (me22.ca+boost_at_[hidden])
Date: 2008-05-28 21:33:56

On Wed, May 28, 2008 at 1:58 AM, Roland Schwarz
<roland.schwarz_at_[hidden]> wrote:
> I have buffer in terms of char, i.e. char buffer[]. This buffer is not
> from stream, file or socket. It comes from a fifo in my application.
> The I want to make use of the buffer as:
>
> if (type == id_foo) {
>        foo& f(*reinterpret_cast<foo*>(&buffer[0]));
>        ... do something with foo ...
>
> }
>
> And I think this is not only ugly but also unnecessary, since foo
> already might be expressed in terms of char[]. If not, e.g. because
> foo is not made of unaligned data, I'd prefer a compiler error
> instead.
>

I think that there's a strong possibility that violates strong
aliasing requirements.

> Btw. read(&foo, sizeof(foo)) also will need to do an equivalent
> of reinterpret cast internally. Doesn't it?
>
> I just think that endian is a fairly general idea that should not
> be limited to stream, file and socket.
>

Is there a usage for it outside of I/O though?  I can't think of one.

Perhaps what's really needed it a "better" (for some criteria I can't
elaborate) I/O system...

> Yes of course I always can do the reinterpret_cast, but if we can
> do better, why shouldn't we?
>
> An alternative I can think of would be to not make the bytes[]
> private.
>

It has to be public, to be POD.