Re: [Boost-users] [intrusive] how to change the value of an item in a set?

From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2008-04-09 11:37:19

Raymond Haeb wrote:
> Hello,
> [snip]

> So the question is in the comment: Is there a way to change the value of 
> an element of a set or insert an (new) element in a set, without having 
> a pointer to the set?

No, sorry. To insert a value in a set you need access to the predicate, 
which is stored in the set. In case the predicate is stateless and the 
constant_time_size is false (as your example shows) I think it's 
possible to implement an static function that removes the node, climbs 
up to the root node of the tree and inserts the new node. Note that if 
your predicate throws, the insertion might fail, and your node would be 
left unlinked. And the function would be really low-level and dangerous 
if used without care. I don't know if this has some deep impact in 
current design, but I will try to see it when I have a bit of time.

Meanwhile, I'm afraid you'll need a pointer to the set ;-)

Regards,

Ion