bors 02b27f1e70 Auto merge of #86860 - fee1-dead:stabilize, r=LeSeulArtichaut ... Stabilize `arbitrary_enum_discriminant` Closes #60553. ---- ## Stabilization Report _copied from https://github.com/rust-lang/rust/issues/60553#issuecomment-865922311_ ### Summary Enables a user to specify *explicit* discriminants on arbitrary enums. Previously, this was hard to achieve: ```rust #[repr(u8)] enum Foo { A(u8) = 0, B(i8) = 1, C(bool) = 42, } ``` Someone would need to add 41 hidden variants in between as a workaround with implicit discriminants. In conjunction with [RFC 2195](https://github.com/rust-lang/rfcs/blob/master/text/2195-really-tagged-unions.md), this feature would provide more flexibility for FFI and unsafe code involving enums. ### Test cases Most tests are in [`src/test/ui/enum-discriminant`](https://github.com/rust-lang/rust/tree/master/src/test/ui/enum-discriminant), there are two [historical](https://github.com/rust-lang/rust/blob/master/src/test/ui/parser/tag-variant-disr-non-nullary.rs) [tests](https://github.com/rust-lang/rust/blob/master/src/test/ui/parser/issue-17383.rs) that are now covered by the feature (removed by this pr due to them being obsolete). ### Edge cases The feature is well defined and does not have many edge cases. One [edge case](https://github.com/rust-lang/rust/issues/70509) was related to another unstable feature named `repr128` and is resolved. ### Previous PRs The [implementation PR](https://github.com/rust-lang/rust/pull/60732) added documentation to the Unstable Book, https://github.com/rust-lang/reference/pull/1055 was opened as a continuation of https://github.com/rust-lang/reference/pull/639. ### Resolution of unresolved questions The questions are resolved in https://github.com/rust-lang/rust/issues/60553#issuecomment-511235271. ---- (someone please add `needs-fcp`)		2021-08-18 01:00:17 +00:00
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book@7e49659102	Update books	2021-08-10 12:38:00 -07:00
edition-guide@3710b0cae7	Update books	2021-07-26 21:46:55 -07:00
embedded-book@4f9fcaa30d	Update books	2021-08-10 12:38:00 -07:00
man	Rollup merge of #59685 - lzutao:patch-1, r=GuillaumeGomez	2019-04-04 15:09:07 +02:00
nomicon@0c7e5bd142	Update books	2021-08-10 12:38:00 -07:00
reference@4884fe45c1	Update books	2021-08-10 12:38:00 -07:00
rust-by-example@0dc9cd4e89	Update books	2021-07-26 21:46:55 -07:00
rustc	Rollup merge of #87677 - amalik18:issue-2788-fix, r=pietroalbini	2021-08-16 23:37:26 +02:00
rustc-dev-guide@c4644b427c	Update books	2021-08-10 12:38:00 -07:00
rustdoc	feature gate doc(primitive)	2021-08-16 05:41:16 +00:00
unstable-book	Auto merge of #86860 - fee1-dead:stabilize, r=LeSeulArtichaut	2021-08-18 01:00:17 +00:00
complement-design-faq.md	Remove the FAQs in favor of the website	2015-12-23 14:03:45 -08:00
complement-lang-faq.md	Remove the FAQs in favor of the website	2015-12-23 14:03:45 -08:00
complement-project-faq.md	Remove the FAQs in favor of the website	2015-12-23 14:03:45 -08:00
favicon.inc	Use https URLs to refer to rust-lang.org where appropriate.	2015-08-09 14:28:46 -07:00
footer.inc	rustdoc: Improve playground run buttons	2016-10-15 18:32:03 +01:00
full-toc.inc
grammar.md	Remove legacy grammar	2019-09-30 07:46:10 +02:00
guide-crates.md	Grammar tweak to old guide stub documents.	2015-01-16 22:25:22 -05:00
guide-error-handling.md	Convert old doc links to current edition	2019-02-13 14:39:25 +00:00
guide-ffi.md	Grammar tweak to old guide stub documents.	2015-01-16 22:25:22 -05:00
guide-macros.md	Grammar tweak to old guide stub documents.	2015-01-16 22:25:22 -05:00
guide-ownership.md	Convert old doc links to current edition	2019-02-13 14:39:25 +00:00
guide-plugins.md	Add top level sections to the Unstable Book.	2017-04-18 21:26:09 -04:00
guide-pointers.md	Convert old doc links to current edition	2019-02-13 14:39:25 +00:00
guide-strings.md	Grammar tweak to old guide stub documents.	2015-01-16 22:25:22 -05:00
guide-tasks.md	Fix broken link in old rust guide	2015-03-04 23:18:24 +00:00
guide-testing.md	Convert old doc links to current edition	2019-02-13 14:39:25 +00:00
guide-unsafe.md	Grammar tweak to old guide stub documents.	2015-01-16 22:25:22 -05:00
guide.md	Grammar tweak to old guide stub documents.	2015-01-16 22:25:22 -05:00
index.md	Add link to rust website	2020-11-04 11:06:42 +01:00
intro.md	Remove the 30 minute intro	2015-04-18 17:55:31 -04:00
not_found.md	dro -> duckduckgo	2018-10-05 08:52:44 -07:00
redirect.inc	Exclude old book redirect stubs from search engines	2019-03-14 22:56:38 +00:00
reference.md	Update reference.md	2021-07-10 19:51:36 +02:00
robots.txt	Block version-specific docs from search engines	2020-03-14 02:29:35 +00:00
rust.css	override rustdoc.css {webkit,moz} box-sizing:unset	2021-06-29 13:05:00 +08:00
rust.md	Avoid linking to a moved page in rust.html	2017-03-29 15:38:47 +02:00
rustdoc.md	Move rustdoc.md into the book	2015-01-21 14:59:25 -05:00
tutorial.md	Update tutorial.md	2018-05-17 12:25:24 -07:00
version_info.html.template	Add alt tags for logos	2016-01-20 11:53:20 -05:00