void main()
{
	
	auto result = readconfig();

	foreach (_; result)
	{
		// I want to iterate result that I got from structure.
	}
}

auto readconfig()
{
	struct ConfigStruct
	{
		string key1;
		string key2;
	}

	ConfigStruct confstruct = ConfigStruct();
	confstruct.key1="Ivan";
	confstruct.key2="admin";

	return confstruct;

}

Suliman:

> void main()
> {
> 	
> 	auto result = readconfig();
>
> 	foreach (_; result)
> 	{
> 		// I want to iterate result that I got from structure.
> 	}
> }
>
> auto readconfig()
> {
> 	struct ConfigStruct
> 	{
> 		string key1;
> 		string key2;
> 	}
>
> 	ConfigStruct confstruct = ConfigStruct();
> 	confstruct.key1="Ivan";
> 	confstruct.key2="admin";
>
> 	return confstruct;
>
> }

Be careful to make ConfigStruct a static struct.

auto readconfig() {
    static struct ConfigStruct {
        string key1, key2;
    }

    return ConfigStruct("Ivan", "admin");
}

void main() {
    import std.stdio;
    auto result = readconfig();

    foreach (field; result.tupleof) {
        writeln(field);
    }
}

Bye,
bearophile

>foreach (field; result.tupleof)

Why I should here specify type of iterable element, but not first element that I use for iteration?

I mean:
foreach (_some_type_possible_enum_ field; result)

?

Suliman:

>>foreach (field; result.tupleof)
>
> Why I should here specify type of iterable element, but not first element that I use for iteration?
>
> I mean:
> foreach (_some_type_possible_enum_ field; result)
>
> ?

I don't understand your question. In my code I have not specified types in the foreach.

Bye,
bearophile

On Friday, 22 August 2014 at 08:44:51 UTC, Suliman wrote:
>>foreach (field; result.tupleof)
>
> Why I should here specify type of iterable element, but not first element that I use for iteration?
>
> I mean:
> foreach (_some_type_possible_enum_ field; result)
>
> ?

You mustn't, because your struct could have fields of different types. When you `foreach()` over a tuple, the compiler unrolls the loop body, which allows it to use a (potentially) different type on each iteration.

If you don't want this, and all the fields have the same type, you can iterate over an array made from the fields:

    foreach (field; [result.tupleof]) {
        writeln(field);
    }

On Friday, 22 August 2014 at 10:44:31 UTC, Marc Schütz wrote:
> On Friday, 22 August 2014 at 08:44:51 UTC, Suliman wrote:
>>>foreach (field; result.tupleof)
>>
>> Why I should here specify type of iterable element, but not first element that I use for iteration?
>>
>> I mean:
>> foreach (_some_type_possible_enum_ field; result)
>>
>> ?
>
> You mustn't, because your struct could have fields of different types. When you `foreach()` over a tuple, the compiler unrolls the loop body, which allows it to use a (potentially) different type on each iteration.
>
> If you don't want this, and all the fields have the same type, you can iterate over an array made from the fields:
>
>     foreach (field; [result.tupleof]) {
>         writeln(field);
>     }

Or you could implement opApply or range primitives in the struct.

http://ddili.org/ders/d.en/foreach_opapply.html
http://dlang.org/phobos/std_range.html