[phobos] is*Range + Qualified Types

[Brad Roberts]

On Thu, 12 Aug 2010, Shin Fujishiro wrote:

> David Simcha <dsimcha at gmail.com> wrote:
> > I'm looking to go on a major debugging spree and make std.range work 
> > with const ranges.  For example, the following should work:
> > 
> > import std.range, std.algorithm;
> > 
> > void main() {
> >      const foo = map!"a ^^ 2"([1,2,3,4,5]);
> >      auto myRetro = retro(foo);
> > }
> 
> Could you elaborate why?
> 
> Ranges with const elements must be common; but what's the point of
> const ranges?  Const random access ranges are usable, but other const
> ranges seem to be useless since popFront and popBack can't be const.
> 
> 
> Shin
> _______________________________________________

The case I ran into that I think is a useful one is being able to use 
const ranges as input to various algorithms, map and filter being the most 
obvious choices.  In my case I was filtering out a few specific records of 
a range of records.

Later,
Brad