Const member initialization list question

[Howard]

Re: Const member initialization list question


"Wolfram Humann" <whumann@gmx.de > wrote in message
news:oprvmzg6x0 1udsjr@netnews. ..[color=blue]
> On 16 Sep 2003 19:00:07 GMT, Howard <alicebt@hotmai l.com> wrote:
>[color=green]
> > If you're just inquiring for information about an existing book,
> > then simply return a reference to one [...], or else return a
> > pointer instead of a reference, and make it nil when the
> > specified book doesn't exist.[/color]
>
> I see your point and I agree that this is a clean solution. Two remarks:
>
> 1. I still could not find any statement in the standard that
> references/pointers to map entries will always remain valid when the map
> grows/shrinks. As I said, I don't think the current implementation of a
> map will reallocate memory (like e.g. the vector does) but I don't want to
> rely on this unless the standard defines that it's illegal for a map to
> reallocate memory for its entries.
>
> 2. Using references or pointes may be more logical than creating
> "redundant" objects but at least for my current project I won't be able to
> do this. My code has to remain consistent with existing code.
>
> Wolfram[/color]

Well, then just write a proper copy-constructor. Let findByTitle return a
const reference (throwing an exception if not found), and pass its result as
the parameter for the constructor, like this:

try
{
BOOK aBook(findByTit le("The Hobbit"));
}
catch(...)
{
//...error?
}

or

try
{
const BOOK& refBook = BOOK::findByTit le("The Hobbit");
BOOK* pPook = new BOOK(refBook);
}
catch(...)
{
// ...error?
}

-Howard