Re: [boost] [safebool] Can we generalize it and put it into utilities?

Subject: Re: [boost] [safebool] Can we generalize it and put it into utilities?
From: Vladimir Batov (vladimir.batov_at_[hidden])
Date: 2009-03-31 18:07:18

> Stewart, Robert <Robert.Stewart <at> sig.com> writes:
> 
> Your examples from English are valid (though my spelling checker wants to
> change "cellphone" to "cell phone" .  

Yes, 'dictionary.com' insists on them being separate... but, in fact, that was
in part my point -- language is a living thing, words get together, move in and
out. Some compound words which used to properly written with a dash (like
multi-storey) are losing dashes. Some never even had the dashes (like 'file
name') but still got together anyway. For many something like file_name will not
probably look right. 

That said, I renamed safebool to safe_bool :-) so that we could pass that point.

> ...
> > { return safebool<Foo>(c); }
> > { return safebool<Foo>::apply(c); }
> 
> The former relies on creating a temporary and accessing a nested type,
> ... The latter involves a static member function, ...
> It's just a more straightforward mechanism with more consistency
> between the return type and invocation, 
> together making it slightly nicer.

I actually agree with you... but that's implementation detail that the user does
not care or deal with. As for the interface due to utter simplicity of that
safe_bool I'd like it to be deployable with as little effort as possible.
Therefore, I feel from the *user* point of view the former wins over the latter. 

> I agree with Steven.  One interface is sufficient.  
> It would be nice to have more opinions, however.  

For the time being I'll keep both (as above).

> I expect this will warrant a fast-track review, 
> but you could hope for more opinions at that time, since few are
> available now.

Yes, a fast-track review makes sense and would be nice... or just a review. :-)
You might have noticed I was not exactly lucky getting to the review phase. :-)
I am probably missing some important process steps (although I did read the
relevant pages). If you could give me a hand with that, it'd be much appreciated
and I'd know how to do it properly without irking people.

> > Yes, I prefer spelling safebool<> for consistency.
> 
> >From that response, I'm unsure whether you took my point.  To be clear, given
the choices,
> 
>   1) safe_bool<Foo>::apply(c) and
>   2) make_safe_bool(this, c),
> 
> and the conversion type,
> 
>      safe_bool<Foo>::type,
> 
> 1) is more consistent than 2), so we should eliminate 2).

Sorry for being unclear. Yes, I like and implemented #1. The 'make_...' has been
removed altogether.

Best,
V.