[boost] [multi_index] use cases for iterator_to()

From: JOAQUIN LOPEZ MU?Z (joaquin_at_[hidden])
Date: 2007-05-17 15:04:57

Hello,

More than a year ago a request was made for
Boost.MultiIndx to provide the ability to
get an iterator to an element x from x alone:

iterator iterator_to(const value_type& x);

I can provide this functionality in constant time,
and the internal implementation is trivial, but
I got thinking about the potential use cases for
such capability and cannot come up with something
convincing.

Do you see usefulness in having iterator_to()?
Can you describe a potential usage scenario? At
first blush, seems like this is at least as useful
as the homonym functionality in Boost.Intrusive,
but if you think about the obvious scenarios
applying to B.I, it turns out they do not immediately
translate to B.MI.

Thank you!

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo