[boost] Re: looping construct

From: Alexander Nasonov (alnsn-mycop_at_[hidden])
Date: 2004-04-21 09:08:18

Alexander Nasonov wrote:

> David Abrahams wrote:
> 
>> John Torjo <john.lists_at_[hidden]> writes:
>> 
>>>> You can also use the rtl (Ranges Template Library):
>>>> (note: I'll rename the library, wince there's another one with the
>>>> same name ;))
>>>>
>>>> for( crange<container> r(cont); r; ++r)
>>>>    *r += 2;
>>>>
>>> p.s. no macros involved in the above statement ;)
>>> Best,
>>> John
>> 
>> That said, you do have have to name the container type.  At the same
>> time, you don't have to name the element type ;-)
> You could get rid of the container type if you recall any_pointer idea.
> But this monster is too slow to be an iterator :)

Another idea. The any_pointer could be made lightweighted. ScopedGuard trick
can help, on one hand, to hide ugly container type behind typedef'd
reference, and, on another hand, to let the compiler remember the "origin".
I suspect the compiler have to be very very clever.

// aka ScopedGuard; library code
typedef crange_base const& crange_base_ref;

// user code
for(crange_base_ref r = make_crange(cont); r; ++r)
    *r += 2;

-- 
Alexander Nasonov
Independent Developer and Consultant