The Rust issue for RFC 231 only covers part of the RFC

[ftxqxd]

The Rust issue for RFC 231 is rust-lang/rust#16640, but that issue only refers to the part of the RFC that changes the syntax for the unboxed closure traits to Fn() etc., which has already been implemented. I couldn’t find an issue for the upvar capture inference part of the RFC, which has not yet been implemented (as far as I know). Should such an issue be created, and the Rust issue for the RFC be changed to that issue?

[alexcrichton]

I've reopened rust-lang/rust#16640, thanks for the sharp eye @P1start!