Proposal for SentinelInputRange

[Walter Bright]

On 2/28/2013 7:37 AM, monarch_dodra wrote:
> Just provide it with a disclaimer than it will only ever be useful for a select
> class of algorithms (parser), but that the optimization opportunity will be
> ignored by the rest of phobos.

1. parsing text is very commonplace

2. it is used in std.regexp in the interpreter engine, a quite different use 
case, but also common to bytecode engines