Returning tuples from functions

[Daniel Keep]

niovol wrote:
> When will it be possible? I have almost no experience in programming on D. But I can't imagine how to solve my problem without using tuples.

No idea; I'd like to know myself.  That said, you have a few alternatives:

1. Use out parameters.  It's like returning a tuple, except you put them
inside the parentheses.

Tuple!(int,int,int) foo()
{
    return Tuple!(1,2,3);
}

Becomes

void foo(out int a, out int b, out int c)
{
    a = 1;
    b = 2;
    c = 3;
}

2. Use Tuple structs.  This is a horrible, nasty trick that is very cool.

struct TupleStruct(T...)
{
    T tuple;

    static TupleStruct!(T) opCall(T args)
    {
        TupleStruct!(T) result;
        foreach( i,a ; args )
            result.tuple[i] = a;
        return result;
    }
}

TupleStruct!(int, int, int) foo()
{
    return TupleStruct!(int, int, int)(1, 2, 3);
}

I believe there is just such a thing in... the standard library
somewhere.  Go poking; you'll find it :P

	-- Daniel

-- 
int getRandomNumber()
{
    return 4; // chosen by fair dice roll.
              // guaranteed to be random.
}

http://xkcd.com/

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