[swift-evolution] [Review] SE-0066: Standardize function type argument syntax to require parentheses

[Tino Heth]

My evaluation mostly depends on the degree of simplification that can be archived, so it's fine for me to let those decide who know best.
Skipping parentheses is convenient, but requiring them won't be that painful — and in case the latter statement is wrong, my general impression is we are in a "slim-down" phase now, and re-adding something back in Swift 3+ won't break anything.

Nonetheless, I like the thought of "all functions take a single parameter", so I'm curious about the history of this deprecated principle.
It is relevant to many topics on the list, and I've never seen a detailed explanation about the pros and cons:
Instead of removing tuple splat, we could as well talk about discarding varargs and inout-parameters… (I don't think default args and internal/external labels are showstoppers here).

Tino