void main() {
    import std.stdio, std.algorithm, std.range, std.conv;

    enum digSum = (int n) => n.text.map!(d => d - '0').sum;
//    enum harshads = iota(1, int.max).filter!(n => n % digSum(n) == 0);
    enum harshads = iota(1, 256).filter!(n => n % digSum(n) == 0);
    harshads.take(20).writeln;
    harshads.filter!(h => h > 1000).front.writeln;
}

// this compiles but always prints 1 number and gets object.Error@(0): Access Violation

Here's the output I get (DMD v2.068.2):

[1, 3, 10, 12, 21, 30, 100, 102, 111, 120, 201, 210]
core.exception.AssertError@std\range\package.d(4603): Assertion failure

On Tuesday, 10 November 2015 at 04:34:22 UTC, Cauterite wrote:
> Here's the output I get (DMD v2.068.2):
>
> [1, 3, 10, 12, 21, 30, 100, 102, 111, 120, 201, 210]
> core.exception.AssertError@std\range\package.d(4603): Assertion failure

iota.front() is complaining the range is empty from this line.

    harshads.filter!(h => h > 1000).front.writeln;

your hardas has no values > 1000 so the filter is empty. hardwas was seeded with iota(1,256), so the maximum value will be 252.

bye,
lobo

On Tuesday, 10 November 2015 at 05:14:29 UTC, lobo wrote:
> On Tuesday, 10 November 2015 at 04:34:22 UTC, Cauterite wrote:
>> Here's the output I get (DMD v2.068.2):
>>
>> [1, 3, 10, 12, 21, 30, 100, 102, 111, 120, 201, 210]
>> core.exception.AssertError@std\range\package.d(4603): Assertion failure
>
> iota.front() is complaining the range is empty from this line.
>
>     harshads.filter!(h => h > 1000).front.writeln;
>
> your hardas has no values > 1000 so the filter is empty. hardwas was seeded with iota(1,256), so the maximum value will be 252.
>
> bye,
> lobo


with dmd 2.069
I always get
--> [1
and then the error no matter what I canhe that line to.

On Tuesday, 10 November 2015 at 14:25:19 UTC, steven kladitis wrote:
> On Tuesday, 10 November 2015 at 05:14:29 UTC, lobo wrote:
>> On Tuesday, 10 November 2015 at 04:34:22 UTC, Cauterite wrote:
>>> Here's the output I get (DMD v2.068.2):
>>>
>>> [1, 3, 10, 12, 21, 30, 100, 102, 111, 120, 201, 210]
>>> core.exception.AssertError@std\range\package.d(4603): Assertion failure
>>
>> iota.front() is complaining the range is empty from this line.
>>
>>     harshads.filter!(h => h > 1000).front.writeln;
>>
>> your hardas has no values > 1000 so the filter is empty. hardwas was seeded with iota(1,256), so the maximum value will be 252.
>>
>> bye,
>> lobo
>
>
> with dmd 2.069
> I always get
> --> [1
> and then the error no matter what I canhe that line to.

Hmm, that's different to what I get. On linux 64 bit with dmd 2.069 I get this:

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 18, 20, 21, 24, 27, 30, 36, 40, 42]
core.exception.AssertError@std/range/package.d(4691): Assertion failure


Note the assertion is same as before; hardas has no values > 252 so filter!(h => h < 1000) results in an empty range.

bye,
lobo

On Thursday, 12 November 2015 at 02:36:23 UTC, lobo wrote:
> On Tuesday, 10 November 2015 at 14:25:19 UTC, steven kladitis wrote:
>> On Tuesday, 10 November 2015 at 05:14:29 UTC, lobo wrote:
>>> [...]
>>
>>
>> with dmd 2.069
>> I always get
>> --> [1
>> and then the error no matter what I canhe that line to.
>
> Hmm, that's different to what I get. On linux 64 bit with dmd 2.069 I get this:
>
> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 18, 20, 21, 24, 27, 30, 36, 40, 42]
> core.exception.AssertError@std/range/package.d(4691): Assertion failure
>
>
> Note the assertion is same as before; hardas has no values > 252 so filter!(h => h < 1000) results in an empty range.
>
> bye,
> lobo

that should be filter!(h => h > 1000)