Re: [boost] Switch library review - summary of discussion so far

From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2008-01-12 10:25:05

Stjepan Rajko wrote:

> * Default default behavior
> 
> Alexander Nasonov has also
> indicated that a throwing default case can cause inefficiency, even
> when it is guaranteed not to be invoked.

Wouldn't an assert be more suited then?
If default behaviour is unspecified and yet invoked, terminating sounds 
like a good thing to do.

> There has been a lengthy discussion on the underlying design of the
> library, what it should offer, and whether the name of the library is
> appropriate.  There are two types of designs that have been put
> forward as being appropriate and/or necessary for a Boost.Switch
> library.  On one hand, there is the submitted design (labeled "A" in
> recent postings), which takes the switch cases in an MPL sequence and
> a single function object containing implementations of all cases.
> Joel de Guzman has proposed another design (labeled "B"), in which the
> switch cases are specified separately and allow a different function
> to be used for each case.

It seems to me that B is convertible to A...
There would be no need to duplicate the interface then.

An utility which converts B to A would be quite useful though, even 
outside of boost.switch.