AA.remove in foreach && AA = new vs cleaning

Steven Schveighoffer schveiguy at yahoo.com
Wed Oct 21 20:08:46 PDT 2009

On Wed, 21 Oct 2009 23:06:47 -0400, Saaa <empty at needmail.com> wrote:

> Is there anything with removing the current key in a foreach?
> foreach (K k, ; aa)
> {
>   ..
>   aa.remove(k);
> }

Yes, behavior is undefined.

 from http://digitalmars.com/d/2.0/statement.html#ForeachStatement :

"The aggregate must be loop invariant, meaning that elements to the  
aggregate cannot be added or removed from it in the [loop body]"

I have gotten around this in dcollections by removing elements outside the  
loop body.  See for example the keypurge function of HashMap  


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