From c1fdc3b3759a257e0cc53d199febb58c264a0718 Mon Sep 17 00:00:00 2001 From: Mark Mansi Date: Mon, 19 Nov 2018 15:34:02 -0600 Subject: [PATCH] finish walkthrough --- src/walkthrough.md | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) diff --git a/src/walkthrough.md b/src/walkthrough.md index 8cd511d9..4eae1397 100644 --- a/src/walkthrough.md +++ b/src/walkthrough.md @@ -228,9 +228,34 @@ members. For the `?` macro feature, we went through a few different iterations after the original implementation: [1][impl2], [2][impl3], [3][impl4]. -TODO - +Along the way, we decided that `?` should not take a separator, which was +previously an unresolved question listed in the RFC. We also changed the +disambiguation strategy: we decided to remove the ability to use `?` as a +separator token for other repetition operators (e.g. `+` or `*`). However, +since this was a breaking change, we decided to do it over an edition boundary. +Thus, the new feature can be enabled only in edition 2018. These deviations +from the original RFC required [another +FCP](https://github.com/rust-lang/rust/issues/51934). ## Stabilization -TODO +Finally, after the feature had baked for a while on nightly, a language team member +[moved to stabilize it][stabilizefcp]. + +[stabilizefcp]: https://github.com/rust-lang/rust/issues/48075#issuecomment-433177613 + +A _stabilization report_ needs to be written that includes + +- brief description of the behavior and any deviations from the RFC +- which edition(s) are affected and how +- links to a few tests to show the interesting aspects + +The stabilization report for our feature is [here][stabrep]. + +[stabrep]: https://github.com/rust-lang/rust/issues/48075#issuecomment-433243048 + +After this, a PR is made to remove the feature gate, enabling the feature by +default (on the 2018 edition). A note is added to the [Release notes][relnotes] +about the feature. + +[relnotes]: https://github.com/rust-lang/rust/blob/master/RELEASES.md