key in aa.keys, but aa[key] give range violation?

[Ali Çehreli via Digitalmars-d-learn]

On 03/29/2016 05:29 PM, Yuxuan Shui wrote:
> On Wednesday, 30 March 2016 at 00:26:49 UTC, Yuxuan Shui wrote:
>> My code looks something like this:
>>
>> bool[ulong][ulong] edge;
>> foreach(u; from)
>>     foreach(v; to_)
>>         edge[u][v] = true;
>> foreach(u; edge.keys) {
>>     auto adj = edge[u];
>>     //....
>> }
>>
>> And sometimes edge[u] would give Range violation error.
>
> I guess I'm not supposed to do aa.remove() while iterate through it?

That was my first guess. No, you cannot mutate the container itself 
while iterating over it.

However, the sample that you've shown should be fine as edge.keys is an 
eagerly generated array of keys. In that case, you can remove from the 
aa. Perhaps your actual code is different?

Ali