Re: [boost] [proto] new version, breaking changes

From: Eric Niebler (eric_at_[hidden])
Date: 2007-05-20 19:31:59

Maurizio Vitale wrote:
> On May 20, 2007, at 4:26 PM, Eric Niebler wrote:
>> 3) You haven't said what proto::if_ and proto::not_ should be.
>>
> I didn't indeed. The reason is that I was concerned with tags that  
> can appear in
> expressions and have a different name in MPL. Then if_ wouldn't be a  
> problem
> and not_ could stay (I'd say should stay) because has the same  
> meaning as mpl::not_.

No, mpl::not_ corresponds to proto::logical_not, and proto::not_ sticks 
out just as proto::or_ does.

> If you want to change both, a possibility would when (for if_) and  
> unless (for not_).

Interesting. All, any, when, and unless are not unreasonable. I know you 
retracted this suggestion in another message, but I want you to bring it 
up again when proto is under review. Naming is super-important, and I 
want more feedback on this issue. I'll remind you when the time comes.

The mpl names come from the standard. "bitor" is an alternate token for 
|. Extending this, bitor_eq is an alternate token for |=, which suggests 
that bitwise_or_assign should be bitor_eq_. But then what about 
operator=? Should that be eq or eq_? These are a bit too terse for my 
taste, and could be confused with ==, which is equal_to. And 
<functional> has equal_to but greater_equal (not greater_equal_to). A 
perfectly consistent set of names may simply be impossible.

-- 
Eric Niebler
Boost Consulting
www.boost-consulting.com