Regarding the "progress", I'd like a good built-in syntax to unpack tuples in assignments, inside function signatures, in foreach statements, and more, because the syntactic contortions I currently adopt to use tuples in D are bad.
I'm partially against to it.
1. I think removing comma operator does not have useful effect for tuple syntax discussion. For example:
1a. If you want to use parenthesis syntax (...) for tuple, we should resolve one-element tuple ambiguity first.
(exp) // one-element tuple, or just an expression ?
And, removing comma operator does not resolve this issue.
1b. If you choose other syntax for tuple, comma operator will be no longer related to tuple syntax discussion.
{exp, exp2} // eg. using brace for tuple syntax no longer touch to comma operator
2. Indeed in some case comma operator is bug-prone, but if it is used directly on the ExpStatement, it's still useful to me.
foreach (e; exp1, exp2) {} // maybe bug?
if (cond) exp1, exp2; // in most case, this is not a bug.
So, completely removing comma operator will cause negative affect in some cases.