>From: "Pavol Droba" <[EMAIL PROTECTED]> > > > On Sun, Nov 24, 2002 at 07:27:42PM +0100, Terje Sletteb? wrote: > > > > For example, if you have a buffer like this (starting at an aligned > > address): > > > > +0 - One byte > > +1 - Number 1 > > +5 - Number 2 > > +9 - Number 3 > > > > Even if you have a struct with three 32-bit ints, no internal padding, if > > you try to map it to the above buffer (at offset 1), on a platform that > > requires 4-byte alignments for ints, it won't work. > > I see your point now. I'have used offset_cast mostly on x86 platform where to > misalignment is tolerated. I have used it also on ARM processor and we have to > make some sort of special arrangements to make it work. For network strutures, > however it worked fine, because most of them are internaly aligned. > > Anyway now I see that in the current implementation offset_cast is too dangerous > and unpredictable and so it is not usable for general purpose.
As you say, and as was pointed out at the start of the thread, it may work on a specific platform (like x86). Perhaps it could be possible to have code that detects the platform, and which could then report an error on misalignment, if that is not tolerated on the given platform. It appears Boost.Config isn't enough for this, though, as it only detects the OS, not the underlying hardware. How did you do it on the ARM? As I understand, it requires word-alignment for words (and half-word alignment for half-words, if that is supported on the given ARM version). > I have mentioned before, that binary analysis could be done also using a more > complicated framework. Would it make sense to create one? What does it do? Regards, Terje _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
