NLL: regressions due to weakness in two-phase borrows

[pnkfelix]

Look at rust-lang/rust-clippy#2982

It seems like some of the changes NLL is requiring were expected to be handled silently by two phase borrows

[pnkfelix]

(its also possible that rust-lang/rust-clippy#2982 was in fact due to this oversight in the 2018 migration mode: #52967 )

[nikomatsakis]

Based on the contents of rust-lang/rust-clippy#2982, it appears @pnkfelix that you now believe these to be legitimate regressions (i.e., NLL-fixed-by-NLL)? I'm inclined therefore to close this issue? Or am I wrong...

[nikomatsakis]

Leaving untriaged for now.

This is fixed. The borrow checker warnings aren't emitted with the current nightly compiler. See rust-lang/rust-clippy#3085.

[nikomatsakis]

Nominating for discussion — probably we can just close this? I put it on the milestone too just to help us keep things tidy

[nikomatsakis]

Hmm, I think I would like to have some minimized reproductions of the cases in question prior to closing. I'd like to look at just what was making them fail before and convince myself that the new behavior is not going to have problems like #38899 (that particular problem does not reoccur, I tested :)