writeln wipes contents of variables ?

[anonymous via Digitalmars-d-learn]

On 22.01.2016 01:49, W.J. wrote:
> How can I identify those ranges, or, how can I tell if any particular
> range has value semantics ? I didn't read any of this in the manual -
> not that I could remember anyways.

Generally you shouldn't. If you care about it either way, use .save or 
std.range.refRange.

If you don't want some range r to be consumed by some operation, pass 
r.save instead of plain r. If you want r to be consumed, pass 
refRange(&r). Only if you don't care if r is consumed or not, should you 
pass simply r.

If you know for a fact that copying r is the same as r.save, then you 
can just pass (and copy) r, of course. We know it's that way with 
dynamic arrays, because of their nature as pointer+length structures. 
But there's nothing wrong with calling .save on an array anyway.

Also, when a function takes a range via a ref parameter, then you don't 
need refRange, of course. The ref parameter ensures that no copy is made 
and that the original range is affected by the function.