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

[bearophile]

Jonathan M Davis:

> It sounds to me like the reason that structural typing is 
> needed is because
> Tuple allows you to name its fields, which I've always thought 
> was a bad idea,

I have appreciated named fields of D tuples since the beginning, 
I have found them quite handy. With them sometimes you don't need 
to unpack a tuple, you can just access its fields with a nice 
name, avoiding to move around more than one variable.

In Python there are build-in tuples, and there is a 
library-defined tuple type that supports names for its fields, it 
even contains its name, so when you print one of them, it's able 
to offer a nice textual representation:

>>> from collections import namedtuple
>>> Point = namedtuple('Point', 'x y')
>>> Point(5, 10)
Point(x=5, y=10)

Bye,
bearophile