On Aug 24, 2009, at 4:11 PM, Martin Jambon wrote:

>
> Oops.
> The following makes it possible for f to be garbage-collected:
>
[...]

If I understand correctly, the closure associated with f will be  
collectable after the lazy_t is forced, whereas before its lifetime  
would be bound to the lifetime of the lazy_t. That's very subtle. It  
would have taken me some time to track that one down if it had come up  
in practice. Thanks,

Warren