Re: [boost] type<>

From: Samuel Krempp (krempp_at_[hidden])
Date: 2002-06-26 13:47:45

On Wed, 2002-06-26 at 16:26, David Abrahams wrote:
> I'm a bit lost. Have your looked at the MPL paper Aleksey and I wrote,

I must confess I hadn't..
Now that I did (by the way, it's brilliant, and quite exciting to read),
I realise that I was not aware that in your mouth 'metafunction' has a
precise meaning given by the conventions stated by this paper.

But until I had read this paper, my intuitive convention for
metafunctions in C++ was :

template<typename T>  class f;

then T is the argument of the metafunction f, and 
f<T> its result.

> It's a question of how you define "metafunction". Obviously, definining it
> in a way which always wraps is not very useful. Such a metafunction can
> never "return" int, for example.

Yes, that's whay I thought that metaprogramming vocubalary would never
be more than analogies when applied to C++..
A more poverful convention like yours makes it possible.

and then, okay, the metafunction really is identity..

That'll teach me for participating in a thread without being aware of
all the pre-requisite knowledge !

-- 
Sam