Re: [boost] [Proto] Review

From: Eric Niebler (eric_at_[hidden])
Date: 2008-03-31 22:55:38

Steven Watanabe wrote:
> AMDG
> 
> Eric Niebler wrote:
>> There's no problem with putting an expression in a terminal, except that 
>> Proto algorithms like matches and deep_copy won't recurse into it.
>>   
> 
> Good to know.  That and the new make_expr allow sufficient
> manual disambiguation for now.  I guess that my main issue with
> make_expr<Domain> for disambiguation is that if we have an
> expression in a domain, we probably don't want to throw away
> the domain information to use it with another domain.

It's as_expr(), not make_expr(). The former will be a no-op if the 
argument is already an expression in the current domain, the latter will 
always make a new expression.

And as_expr() doesn't lose the domain information of its argument -- it 
just adds an additional domain wrapper, so you might get 
stevens_wrapper<lambda_wrapper<expr<...> > >. But I haven't yet figured 
a good way to expose the nested domain information. A use case would help.

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