[swift-evolution] Proposal: Closures capture weak by default

[Matthew Johnson]

> This paves the way for another swift evolution request, actually. The `var` in lazy and the `private(set)` are often plasters on properties that are *intended* to be immutable, but can not be because of the current limitations of the language.

And even worse is the need to declare things as Optional var members (usually IUO) when they can't be fully initialized in phase 1 due to dependency issues.

I would love to see proposals aimed at solving these problems.