Re: [Boost-users] [MPL] Front of a set of types

Subject: Re: [Boost-users] [MPL] Front of a set of types
From: Marco Guazzone (marco.guazzone_at_[hidden])
Date: 2009-09-01 04:18:39

On Mon, Aug 31, 2009 at 10:51 AM, OvermindDL1<overminddl1_at_[hidden]> wrote:
> Yea, I agree that the documentation on this should be cleared, not
> necessarily by saying that front returns possibly any element, but
> rather how it internally stores the type so we know what things like
> front/back/etc. will actually do.  :)

Hmmm... But in this way (i.e., tying an high-level behavior to a
low-level detail) we (as users) loose any advantage of encapsulation.

I think it would be better to fix (and document) the behavior of
"front< set >" regardless of the internal representation of a set.
That is, the front element of a set is "blah blah blah" regardless of
how a set is internally implemented.

Another solution is to deprecate and subsequently remove this
operation from sets; but probably this impacts on backward
compatibility.

Ah, obviously the same issue apply to mpl::map (didn't tried yet but
conceptually the front of a map has an ambiguos meaning)

-- Marco