Changing elements during foreach

[Krzysztof Ciebiera]

On Monday, 21 October 2013 at 14:59:54 UTC, Alexandr Druzhinin 
wrote:
> If you switch instruction order you create local copy and then 
> set x[0] in local copy so original is unchanged. But local copy 
> creating depends on several thing and happens not every 
> appending in general. Your way is not D-ish one. What do you 
> want to do?

I have an array of solutions to a problem. Each solution is an 
array of elements (not numbers, but objects of some classes). 
What I want to do is: I want to take a look at every single 
solution and extend it if it is possible (eg. if solution 
contains obbects a,b,c it can also contain d). The whole thing is 
rather big so I don't want to have any nice functional-style 
solution which will involve copying data. Especially since I have 
to perform similar extensions over and over again.

I understand slices now and I don't find it consistent with "no 
shoot in the foot by default" statement.
--
KC