Prevent copy of range in foreach

[Mike Parker via Digitalmars-d-learn]

On Wednesday, 31 August 2016 at 23:38:21 UTC, Yuxuan Shui wrote:

>
> OK, this would work for cases like containers. But what if I 
> represent buffered network input as a range (like File.byLine), 
> and I don't want to copy the buffer all the time? Any 
> suggestion on how to do that correctly?

Then the range should be constructed with a slice of the buffer 
if it's an array or with something pointer-based if it isn't 
(which requires a bit of bookkeeping). Ranges should be 
lightweight and should never require copying of the underlying 
data.