"David Abrahams" <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > [...] > Hmm, no. The contract would have to be that if StoragePolicy > throws an exception, it frees the resource passed as its constructor > argument. There's nothing wrong with a requirement like that in > principle.
I see. We don't need StoragePolicy to be constructed. We just need it to be constructed before everything else. Makes sense. > [...] > > It seems that the function try block is slightly more powerful, > > because it does not require StoragePolicy() to be no-throw. > > Yes and no. > > 1. Aren't function try blocks somewhat non-portable in practice? Are they? You mean because they aren't implemented well? > 2. Isn't it only the StoragePolicy that knows how to free the > resource? Hmm...technically yes. If the StoragePolicy were fully constructed, you could ask it to free the resource. But then you're requiring it to be no-throw to begin with. So it seems that they give you nothing, as usual. ;) Unfortunately, neither does a managed pointer in the StoragePolicy. Sure, it frees the resource in the presence of exceptions, but it also frees it in the absence of exceptions, which is quite too often. Namely, it doesn't know when it *shouldn't* free the resource, because it doesn't know about Ownership. So now it looks like we're back to that pesky function try-block, and requiring StoragePolicy to be no-throw. :( Dave _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
