to invalidate a range

[Ellery Newcomer]

On 08/12/2011 03:13 PM, bearophile wrote:
> Ellery Newcomer:
>
>> in std.container, the stable* container functions advocate that they do
>> not invalidate the ranges of their containers. What does it mean to
>> invalidate a range?
>
> Generally modifying a collection while you iterate on it causes troubles. When you iterate on a range and you modify the range during the iteration Python gives you an error, because the "for" temporary sets boolean inside the iteratee. In D this problem was avoided in another way, using those stable functions.
>
> Bye,
> bearophile

I am not convinced of this. In the following code, there is definitely a 
problem; it just remains to be seen whether the range is invalidated, or 
merely noisy according to the specified semantics.


import std.container;
import std.stdio;
import std.array;

void main(){
     auto arr = make!(Array!int)([1,2,3]);
     auto r = arr[];
     writeln(array(r.save()));
     arr.stableRemoveAny();
     writeln(array(r.save()));
}