Re: [boost] bind/lambda/phoenix and result_of

From: Arkadiy Vertleyb (vertleyb_at_[hidden])
Date: 2006-05-11 10:11:47

"David Abrahams" <dave_at_[hidden]> wrote

> >> Furthermore, it's _my_ library that needs result_of, so basically I
> >> would be telling users, "if you get a cryptic error message that
> >> looks like ___________, find some of the types in it and register
> >> them with this cryptic macro."
> >
> > The error messages re lack of registration are not that bad IMO.
>
> Bad for you and bad for a user are two totally distinct things.

Just a couple more questions:

1) Do you consider typeof error messages more cryptic than error messages
produced by other boost libraries?  Or STL?  Is there such a thing as
(portable) non-cryptic error message in template programming?

2) What is *cryptic* about registration macros?

Also note that the user doesn't have to "find" the type in the message -- 
it's right there, saying something like TypeNotRegistered=blah<...;  and
it's always about user's own type if lambda types are indeed registered (if
we are talking about lambda).  And it seems to me that it's much easier to
register lambda types than implement what you propose.

I am not sure we are all on the same page here.  AFAIU, the registration
problem applies only to user-defined lambda functors.  And if the user goes
as far as implementing his own lambda functor, to register it with typeof is
just a snap.  And nothing "cryptic" about it.

Regards,
Arkadiy