DIP19: Remove comma operator from D and provision better syntactic support for tuples

[foobar]

On Thursday, 27 September 2012 at 10:58:12 UTC, Jonathan M Davis 
wrote:
> On Thursday, September 27, 2012 11:37:10 foobar wrote:
>> I do _not_ want to consider two different _structs_ (nominal
>> types) as the same type. I would like to get correct tuple
>> semantics which means _structural_ typing (I thought I 
>> emphasized
>> that enough in the OP).
>> A tuple is defined by its contained types, *not* its name.
>
> What on earth does structural typing get you here? A tuple is a 
> collection of
> values of varying types. If you have Tuple!(X, Y, Z), it 
> defines a tuple
> containing the types X, Y, and Z. _All_ tuples with those types 
> will be Tuple!
> (X, Y, Z). The _only_ reason that this isn't quite the case is 
> the nonsense
> with being able to give names to the fields in a tuple (and 
> adding an alias
> this to Tuple should be able to fix that). Being able to create 
> your own tuple
> type which you can compare with Tuple simply because it happens 
> to hold the
> same types is completely pointless as far as I can tell (but 
> you can still do
> it if you really want to). If you want a tuple, then just use
> std.typecons.Tuple. Creating another tuple type buys you 
> nothing.
>
> - Jonathan M Davis

std.typecons.Tuple *is* a struct.
I agree with the above definition of tuples, but I want the 
language to ensure that which at the moment it can't.