Re: [Boost-users] Library Interface Design

From: Geoff Worboys (geoff_at_[hidden])
Date: 2006-09-17 19:00:11

Yuval Ronen wrote:
> As I explained in another post in this thread, I think
> boost::optional is the ultimate solution to the active/inactive
> state problem, so the class itself can still have single phase
> construction.

There is a lot about boost::optional that I am not entirely
happy about, but we dont really want to get into that on this
thread, however the general idea of using optional or a similar
facility is still very interesting.

I imagine that the idea would be to refactor the current class
with active/inactive state into two separate classes.  The long
lived object (needed for complex structural reasons) that would
operate as normal, but all the active-dependent interface would
be moved to the new/separate class and accessed through a
member function returning an optional<T> (or similar).

I can see where this would make excellent sense in several of
my applications.  To optimise access inside tight loops you
could assign the optional<T> to a T& - and so only be checking
existence at the start...  as opposed to my present problem of
having to choose between assertion or exception checking at the
top of each top-level class function.

Yes, I like the thought very much.  Thank you.

-- 
Geoff Worboys
Telesis Computing