Re: [Boost-users] BOOST_FOREACH with Index

Subject: Re: [Boost-users] BOOST_FOREACH with Index
From: OvermindDL1 (overminddl1_at_[hidden])
Date: 2009-12-13 21:11:50

On Sun, Dec 13, 2009 at 6:41 PM, Nat Goodspeed <nat_at_[hidden]> wrote:
> Eric Niebler wrote:
>
>>>> Â  Â Why not:
>>>>
>>>> Â  Â  int index = 0;
>>>>
>>>> Â  Â  BOOST_FOREACH(const Foo &f, foos)
>>>> Â  Â  {
>>>> Â  Â  Â  // ... stuff ...
>>>> Â  Â  Â  ++index;
>>>> Â  Â  }
>
>> What value BOOST_FOREACH has comes primarily from its ability to simplify
>> something that's already pretty darn simple -- a plain for(;;) loop. I
>> strongly resist any effort to make BOOST_FOREACH more complicated, unless
>> the wins are truly significant. In this case, I don't think they are.
>
> Maybe this shouldn't be a BOOST_FOREACH feature at all. As with Python's
> builtin enumerate() function, maybe what we want here is an iterator adapter
> that dereferences to a std::pair<index_type, original_iterator_value_type>?

Ooo, that makes sense, as long as it can still be done quickly (ala
the in index = 0; example above):
BOOST_FOREACH(size_t i, const Foo &f, ENUMERATE(foos))

Or maybe:
BOOST_FOREACH_ENUMERATE(size_t i, const Foo &f, foos)