Re: [boost] Re: basic guarantees in variant

From: E. Gladyshev (egladysh_at_[hidden])
Date: 2003-10-09 15:00:35

--- Brian McNamara <lorgon_at_[hidden]> wrote:
> On Wed, Oct 08, 2003 at 08:48:28PM -0700, E. Gladyshev wrote:
> > Here is how I would do it.
> ...
> > //doesn't throw
> > void variant_copy( char* dst, char* src, size_t size ) {
> >     for( size_t i = 0; i < size; ++i, ++dst, ++src ) {
> >         *dst =  *src;
> >     }
> > }
> ...
> >         //save the current data
> >         variant_copy( b1, data_, size );
> ...
> >             //copy the new object to another storage
> >             variant_copy( b2, data_, size );
> >             //copy the original object back for destruction
> >             variant_copy( data_, b1, size );
> >             static_cast<T*>((void*)data_)->~T();
> >             //put the new object back in place
> >             variant_copy( data_, b2, size );
> 
> This is clever.  Is it legal?  I know it's legal for POD types.  I can't
> find text in the standard which makes it legal for non-POD types.  But
> at the same time, offhand I can't imagine an implementation where it
> wouldn't work.

Brian, where in my code do you see non-POD copying?
All it does, it copies one char[] to another char[] 
(both are POD types).
The char arrays where allocated as char arrays 
originally, there is not any casting going on.
What are you concerns exactly?

Eugene

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