Cool thing about D, number #72

[Daniel Keep]

Bill Baxter wrote:
> Daniel Keep wrote:
>>
>> I discovered the same thing, by roughly the same thinking.  I was
>> working with DFL and cairo, and was using DFL's color structure.
>> Problem was that DFL's stored using ubytes, and I wanted doubles.
>>
>> So when I was writing my own colour structure, as I was defining the
>> storage, I wrote
>>
>>> union
>>> {
>>>     struct { double r, g, b, a; }
>>>     double[4] rgba;
>>> }
>>
>> And it suddenly hit me: I could add a tuple!
> 
> How's that? You add an alias Tuple!(something ) to the union?

Tuple!(double,double,double,double) tuple;

Actually, I made a template called repeatT that lets me write that as
repeatT!(4, double) tuple, but you get the idea :)

>> Now, I have .tuple members for my colour structs, vectors, quaternions,
>> matrices, and just about every other aggregate type I've written.
>>
>> One thing that would make this an order of magnitude more useful would
>> be the ability to return a tuple from a function.
>>
>> But I agree: it's cool :)
>>
>>     -- Daniel
>>
>> P.S.  I use .tuple instead of .tupleof because I don't want to shadow
>> the very-useful compile-time property :)
> 
> I'm just using the compiler's .tupleof property directly.
> 
> --bb

... *slaps forehead*.

In my defense, tho, I imagine it wouldn't have worked quite as well with
the union there :P  Also means I can access the elements as individual
variables, as an array *and* as a tuple.  The last one comes in handy
for unrolling loops :)

	-- Daniel

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

http://xkcd.com/

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