The following code fails to compile because unpredictableSeed is impure:

    void main()
    {
        foreach(i; 0..10) writeln(pureRandom);
    }

    pure uint pureRandom()
    {
        auto r = Random(unpredictableSeed);
        return r.front;
    }

However, make unpredictableSeed a default argument, wrap the call in another pure function, and it compiles:

    void main()
    {
        foreach(i; 0..10) writeln(pureRandom2);
    }

    pure uint pureRandom2()
    {
        return pureRandom;
    }

    pure uint pureRandom(uint seed = unpredictableSeed)
    {
        auto r = Random(seed);
        return r.front;
    }

I'm inclined to believe this is a bug. While pureRandom could be considered weakly pure, pureRandom2 has no arguments so it should be strongly pure. Yet, it yields a different value on every call.

On Tuesday, 10 March 2015 at 21:56:39 UTC, Xinok wrote:
>
> I'm inclined to believe this is a bug.

https://issues.dlang.org/show_bug.cgi?id=11048

On Tuesday, 10 March 2015 at 22:00:29 UTC, safety0ff wrote:
> On Tuesday, 10 March 2015 at 21:56:39 UTC, Xinok wrote:
>>
>> I'm inclined to believe this is a bug.
>
> https://issues.dlang.org/show_bug.cgi?id=11048

Thanks for the link, and I didn't mean to post this in D.learn. >.<