[boost] Re: [OT] Hiding template parameters [was: FC++ Formal review is...]

From: Daniel Frey (daniel.frey_at_[hidden])
Date: 2004-02-17 11:01:57

Gabriel Dos Reis wrote:
> What I think is:  If we accept the principle that scopes should nest,
> then we should accept its logical consequences; if don't want to
> accept those logical consequences, then we should abandon the idea
> that scopes nest.  Which one do you want to pick?

I like the idea of nested scopes, still the question is which scopes 
should be nested in which order. You seem to imply a contradiction where 
I don't see any. It's not the literal order of characters typed that 
*must* define the order of scopes, we have the freedom to think about 
this from a user's perspective and differ from the strict literal order. 
Inconsistent? Maybe, but if it helps to write code in the *sense* of 
nested scopes, I'm fine with it. This - of course - opens the question 
what this sense is, and I am certainly not qualified to define it. Maybe 
Bjarne could clarify what was originally intended. :)

All I can say - and I seem to be consistent with several other folks - 
is, that I would like to see the scope for template-parameters be nested 
inside the base-class' scope, not outside. A small change which makes 
the code more managable by increasing the locality of names from a human 
reader's perspective.

> If you think it is wrong, while being consistent with first principle,
> then propose a a new first principle.  The worst thing to do, I
> believe, is to introduce  barnacled hacks that comes from nowhere.

> We need general rules on which to decide, we don't need barnacled
> hacks that would appear "intuitive" at a moment when we don't have a
> working definition of "intuitive".

I feel accused of "introducing barnacled hacks that come from nowhere". 
I don't think you meant to be insulting, but would you mind to assume 
that I'm not just seeing things from such a narrow perspective? I could 
also assume you are just "blindly applying rules without looking at the 
consequences" - but I think you have better reasons for your POV.

I am actually trying to see where the idea of nested scopes comes from 
and what purpose it fulfills. This purpose is IMHO to keep the code 
readable with the smallest amount of code involved and the least number 
of interactions between the names of different scopes. This keeps the 
code readable, maintainable, etc. and leads to fewer surprises. In that 
sense, the current order of nesting scopes is consistent with the pure 
logic of nested scopes applied, but it's IMHO against the spirit of 
nested scopes.

> If the scope of the template-parameters should come after the scope
> of base classes -- that is the way I understand you "is closer" --
> then one would not be able to use template-parameters in base classes.

I don't understand this. The scope of the base classes identifiers is 
not the scope where the base classes of a class are enumerated.

Regards, Daniel

-- 
Daniel Frey
aixigo AG - financial solutions & technology
Schloß-Rahe-Straße 15, 52072 Aachen, Germany
fon: [phone], fax: [phone]
eMail: daniel.frey_at_[hidden], web: http://www.aixigo.de