Article on Tuples

[Don Clugston]

Walter Bright wrote:
> Don Clugston wrote:
>> Walter Bright wrote:
>>> http://www.digitalmars.com/d/tuple.html
>>
>> "A tuple is a sequence of elements. Those elements can be types, 
>> expressions, or aliases."
>>
>> Is this wording correct? How can you make an alias tuple?
> 
> Just pass in symbols as template arguments to a U...

Awesome! This is even better than I thought.
One problem -- it seems that if the tuple has a mix of types and 
instances, you can't index it.
-------------
struct S { int x; long y; }

template Tuple(E...)
{
     alias E Tuple;
}

void main()
{
     int q;

     alias Tuple!(S, q) Z;
     alias Z[0] R; // fails -- "tuple E is used as a type"
}
-------------
Also, is there any way to get .tupleof to return an alias tuple?
For example, you can't write
alias S.tupleof[0] R;

Nor (more importantly) can you pass it as an template alias parameter:

template Z(alias W) {
     const int Z = 2;
}

const int x = Z!((S.tupleof[0]));

(If it worked, I could write a dump!(X) which would display all the 
names of the members of X, with their values...).