Re: std::binder1st and transform_iterator (was Re: [boost] iterator adaptors & concept checks)

From: David Abrahams (abrahams_at_[hidden])
Date: 2001-03-29 16:28:23

----- Original Message -----
From: "Jeremy Siek" <jsiek_at_[hidden]>

> On Thu, 29 Mar 2001, David Abrahams wrote:
> abraha> Or, perhaps the requirement of default-constructibility does.
Consider a new
> abraha> dimension of granularity for your iterator category refinement!
>
> Hmm, I think it would be pretty bad to have iterators that are not defualt
> constructible. For example, you couldn't use tie() to intialize a pair of
> them...

tie() is cute, but unneccessary; default-construct + tie is maybe even
inefficient, depending on the iterator.

>  shoot, putting iterators in std::pair at all would become
> problematic.

Why? There's no default-construction here:

  std::pair<Iterator1,Iterator2>(i1, i2)

-Dave