Document all features

[chriskrycho]

Overview

Tracking issue for RFC #1636. Let's make the reference a reliable resource for all Rustaceans! 🎉 This might seem intimidating, but the reality is that if we just chip away at it together, we'll be done in no time!

I'm going to be updating this parent issue with a master list of items that need to be documented in the reference as I find them. Quoting the RFC text:

Updating the reference should proceed stepwise:

1. Begin by adding an appendix in the reference with links to all accepted RFCs which have been implemented but are not yet referenced in the documentation.
2. As the reference material is written for each of those RFC features, remove it from that appendix.

Note that step 1 should be fairly straightforward; the main issue will be assembling the list of accepted-and-implemented-but-undocumented RFCs. (Also, any RFCs accepted before RFC 1636 but not yet stabilized should presumably be documented under the rules it establishes, but if I'm wrong about that, someone should let me know and I'll include them as well.)

Also, a pre-emptive apology for the scale of this issue description. We have let things get into a rough spot. (I plan to create documentation issues for each of the required items below once this list is completed, so this thread doesn't become completely unmanageable.)

Status: Last updated May 13, 2017, now processing a copy of @Eh2406's wonderful gist based on @matthewjasper's fork here.

"How Can I Help?"

For right now, since you can't submit updates to the issue directly, there are two major ways you can help:

1. Write documentation. For the RFCs already triaged and filed under the major section C. Documentation Needed and specifically the subsection 2. Write reference material for undocumented, implemented, stabilized RFC features below, you can open a pull request and reference this issue in its description. I'll keep an eye out for inbound links here and add those links to the relevant items, and once they're merged, we'll mark that item as done.

2. Triage issues. Work the gist where I'm tracking the triaged-state, specifically looking at the Not Reviewed at All and Stabilized, Not Reviewed sections and evaluating whether they're documented or not. You can fork the gist and I will keep an eye out, checking roughly daily, for any changes to merge back into that document. (Do take a look at what others may have forked it so you don't duplicate work needlessly!) I'll then pull those over into this master issue.

   When working through those, if you determine that they're already documented, please leave a note (and link!) on your copy of the gist as to where so I can link it in this document. That dramatically decreases the time it takes me to confirm it—I double-check all of these.

A. Tracking

(This section will go away entirely once all of the RFCs have been flagged for documenting or marked documentation-not-needed here.)

RFCs reviewed

Currently: 115/301

• 0001-private-fields.md
• 0002-rfc-process.md
• 0003-attribute-usage.md
• 0008-new-intrinsics.md
• 0016-more-attributes.md
• 0019-opt-in-builtin-traits.md
• 0026-remove-priv.md
• 0034-bounded-type-parameters.md
• 0040-libstd-facade.md
• 0042-regexps.md
• 0048-traits.md
• 0049-match-arm-attributes.md
• 0050-assert.md
• 0059-remove-tilde.md
• 0060-rename-strbuf.md
• 0063-module-file-system-hierarchy.md
• 0066-better-temporary-lifetimes.md
• 0068-const-unsafe-pointers.md
• 0069-ascii-literals.md
• 0071-const-block-expr.md
• 0079-undefined-struct-layout.md
• 0086-plugin-registrar.md
• 0092-struct-grammar.md
• 0093-remove-format-intl.md
• 0109-remove-crate-id.md
• 0112-remove-cross-borrowing.md
• 0115-rm-integer-fallback.md
• 0123-share-to-threadsafe.md
• 0131-target-specification.md
• 0132-ufcs.md
• 0135-where.md
• 0139-remove-cross-borrowing-entirely.md
• 0155-anonymous-impl-only-in-same-module.md
• 0164-feature-gate-slice-pats.md
• 0179-and-mut-patterns.md
• 0184-tuple-accessors.md
• 0199-ownership-variants.md
• 0202-subslice-syntax-change.md
• 0214-while-let.md
• 0218-empty-struct-with-braces.md
• 0230-remove-runtime.md
• 0240-unsafe-api-location.md
• 0235-collections-conventions.md
• 0236-error-conventions.md
• 0256-remove-refcounting-gc-of-t.md
• 0341-remove-virtual-structs.md
• 0342-keywords.md
• 0344-conventions-galore.md
• 0356-no-module-prefixes.md
• 0379-remove-reflection.md
• 0385-module-system-cleanup.md
• 0390-enum-namespacing.md
• 0403-cargo-build-command.md
• 0430-finalizing-naming-conventions.md
• 0445-extension-trait-conventions.md
• 0446-es6-unicode-escapes.md
• 0450-un-feature-gate-some-more-gates.md
• 0495-array-pattern-changes.md
• 0505-api-comment-conventions.md
• 0507-release-channels.md
• 0520-new-array-repeat-syntax.md
• 0531-define-rfc-scope.md
• 0533-no-array-elem-moves.md
• 0544-rename-int-uint.md
• 0556-raw-lifetime.md
• 0558-require-parentheses-for-chained-comparisons.md
• 0560-integer-overflow.md
• 0563-remove-ndebug.md
• 0565-show-string-guidelines.md
• 0803-type-ascription.md
• 1054-str-words.md
• 1057-io-error-sync.md
• 1058-slice-tail-redesign.md
• 1066-safe-mem-forget.md
• 1068-rust-governance.md
• 1096-remove-static-assert.md
• 1102-rename-connect-to-join.md
• 1105-api-evolution.md
• 1119-result-expect.md
• 1122-language-semver.md
• 1123-str-split-at.md
• 1131-likely-intrinsic.md
• 1199-simd-infrastructure.md
• 1214-projections-lifetimes-and-wf.md
• 1242-rust-lang-crates.md
• 1317-ide.md
• 1331-grammar-is-canonical.md
• 1358-repr-align.md
• 1398-kinds-of-allocators.md
• 1432-replace-slice.md
• 1566-proc-macros.md
• 1567-long-error-codes-explanation-normalization.md
• 1574-more-api-documentation-conventions.md
• 1576-macros-literal-matcher.md
• 1589-rustc-bug-fix-procedure.md
• 1590-macro-lifetimes.md
• 1607-style-rfcs.md
• 1618-ergonomic-format-args.md
• 1620-regex-1.0.md
• 1624-loop-break-value.md
• 1636-document_all_features.md
• 1640-duration-checked-sub.md
• 1643-memory-model-strike-team.md
• 1644-default-and-expanded-rustc-errors.md
• 1665-windows-subsystem.md
• 1683-docs-team.md
• 1721-crt-static.md
• 1725-unaligned-access.md
• 1728-north-star.md
• 1774-roadmap-2017.md
• 1828-rust-bookshelf.md
• 1845-shared-from-slice.md
• 1860-manually-drop.md
• 1869-eprintln.md
• 1884-unstable-sort.md

RFCs unreviewed

• 0085-pattern-macros.md
• 0087-trait-bounds-with-plus.md
• 0089-loadable-lints.md
• 0090-lexical-syntax-simplification.md
• 0100-partial-cmp.md
• 0107-pattern-guards-with-bind-by-move.md
• 0111-index-traits.md
• 0114-closures.md
• 0116-no-module-shadowing.md
• 0130-box-not-special.md
• 0136-no-privates-in-public.md
• 0141-lifetime-elision.md
• 0151-capture-by-value.md
• 0160-if-let.md
• 0168-mod.md
• 0169-use-path-as-id.md
• 0192-bounds-on-object-and-generic-types.md
• 0194-cfg-syntax.md
• 0195-associated-items.md
• 0198-slice-notation.md
• 0201-error-chaining.md
• 0212-restore-int-fallback.md
• 0213-defaulted-type-params.md
• 0216-collection-views.md
• 0221-panic.md
• 0231-upvar-capture-inference.md
• 0234-variants-namespace.md
• 0241-deref-conversions.md
• 0243-trait-based-exception-handling.md
• 0246-const-vs-static.md
• 0255-object-safety.md
• 0320-nonzeroing-dynamic-drop.md
• 0326-restrict-xXX-to-ascii.md
• 0339-statically-sized-literals.md
• 0369-num-reform.md
• 0378-expr-macros.md
• 0380-stabilize-std-fmt.md
• 0387-higher-ranked-trait-bounds.md
• 0401-coercions.md
• 0404-change-prefer-dynamic.md
• 0418-struct-variants.md
• 0438-precedence-of-plus.md
• 0439-cmp-ops-reform.md
• 0447-no-unused-impl-parameters.md
• 0453-macro-reform.md
• 0458-send-improvements.md
• 0459-disallow-shadowing.md
• 0461-tls-overhaul.md
• 0463-future-proof-literal-suffixes.md
• 0469-feature-gate-box-patterns.md
• 0474-path-reform.md
• 0486-std-ascii-reform.md
• 0490-dst-syntax.md
• 0494-c_str-and-c_vec-stability.md
• 0501-consistent_no_prelude_attributes.md
• 0503-prelude-stabilization.md
• 0504-show-stabilization.md
• 0509-collections-reform-part-2.md
• 0517-io-os-reform.md
• 0522-self-impl.md
• 0526-fmt-text-writer.md
• 0528-string-patterns.md
• 0529-conversion-traits.md
• 0532-self-in-use.md
• 0534-deriving2derive.md
• 0546-Self-not-sized-by-default.md
• 0550-macro-future-proofing.md
• 0572-rustc-attribute.md
• 0574-drain-range.md
• 0580-rename-collections.md
• 0587-fn-return-should-be-an-associated-type.md
• 0592-c-str-deref.md
• 0593-forbid-Self-definitions.md
• 0599-default-object-bound.md
• 0601-replace-be-with-become.md
• 0639-discriminant-intrinsic.md
• 0640-debug-improvements.md
• 0702-rangefull-expression.md
• 0735-allow-inherent-impls-anywhere.md
• 0736-privacy-respecting-fru.md
• 0738-variance.md
• 0769-sound-generic-drop.md
• 0771-std-iter-once.md
• 0809-box-and-in-for-stdlib.md
• 0823-hash-simplification.md
• 0832-from-elem-with-love.md
• 0839-embrace-extend-extinguish.md
• 0840-no-panic-in-c-string.md Update 0840-no-panic-in-c-string.md
• 0873-type-macros.md
• 0879-small-base-lexing.md
• 0888-compiler-fence-intrinsics.md
• 0909-move-thread-local-to-std-thread.md
• 0911-const-fn.md
• 0921-entry_v3.md
• 0940-hyphens-considered-harmful.md
• 0953-op-assign.md
• 0968-closure-return-type-syntax.md
• 0979-align-splitn-with-other-languages.md
• 0980-read-exact.md
• 0982-dst-coercion.md
• 1011-process.exit.md
• 1014-stdout-existential-crisis.md
• 1023-rebalancing-coherence.md
• 1030-prelude-additions.md
• 1040-duration-reform.md
• 1044-io-fs-2.1.md
• 1047-socket-timeouts.md
• 1048-rename-soft-link-to-symlink.md
• 1135-raw-pointer-comparisons.md
• 1152-slice-string-symmetry.md
• 1156-adjust-default-object-bounds.md
• 1174-into-raw-fd-socket-handle-traits.md
• 1183-swap-out-jemalloc.md
• 1184-stabilize-no_std.md
• 1191-hir.md
• 1192-inclusive-ranges.md
• 1193-cap-lints.md
• 1194-set-recovery.md
• 1200-cargo-install.md
• 1201-naked-fns.md
• 1210-impl-specialization.md
• 1211-mir.md
• 1212-line-endings.md
• 1216-bang-type.md
• 1219-use-group-as.md
• 1228-placement-left-arrow.md
• 1229-compile-time-asserts.md
• 1236-stabilize-catch-panic.md
• 1238-nonparametric-dropck.md
• 1240-repr-packed-unsafe-ref.md
• 1241-no-wildcard-deps.md
• 1252-open-options.md
• 1257-drain-range-2.md
• 1260-main-reexport.md
• 1268-allow-overlapping-impls-on-marker-traits.md
• 1270-deprecation.md
• 1288-time-improvements.md
• 1291-promote-libc.md
• 1298-incremental-compilation.md
• 1300-intrinsic-semantics.md
• 1307-osstring-methods.md
• 1327-dropck-param-eyepatch.md
• 1328-global-panic-handler.md
• 1359-process-ext-unix.md
• 1361-cargo-cfg-dependencies.md Add extension ".md
• 1399-repr-pack.md
• 1415-trim-std-os.md
• 1419-slice-copy.md
• 1422-pub-restricted.md
• 1434-contains-method-for-ranges.md
• 1440-drop-types-in-const.md
• 1443-extended-compare-and-swap.md
• 1444-union.md
• 1445-restrict-constants-in-patterns.md Remove duplicate 0000-restrict-constants-in-patterns.md
• 1461-net2-mutators.md
• 1467-volatile.md
• 1479-unix-socket.md
• 1492-dotdot-in-patterns.md
• 1498-ipv6addr-octets.md
• 1504-int128.md
• 1506-adt-kinds.md
• 1510-cdylib.md Rename 1510-rdylib.md to 1510-cdylib.md
• 1513-less-unwinding.md
• 1521-copy-clone-semantics.md
• 1522-conservative-impl-trait.md
• 1525-cargo-workspace.md
• 1535-stable-overflow-checks.md
• 1542-try-from.md
• 1543-integer_atomics.md
• 1548-global-asm.md
• 1552-contains-method-for-various-collections.md
• 1559-attributes-with-literals.md
• 1560-name-resolution.md
• 1561-macro-naming.md
• 1581-fused-iterator.md
• 1623-static.md
• 1649-atomic-access.md
• 1653-assert_ne.md
• 1660-try-borrow.md
• 1679-panic-safe-slicing.md
• 1681-macros-1.1.md
• 1682-field-init-shorthand.md
• 1696-discriminant.md
• 1717-dllimport.md

B. Status unclear

Some of these are still in-flight; and some of them are just the kind of thing that I don't even fully grok yet well enough to see if they're documented. For these, unchecked means "status unknown"; checked means "status known and added to the latter bits appropriately."

• #0019: Opt-in built-in traits (OIBITs)
  • status query

C. Documentation needed

0. Accepted, not-yet-stabilized, undocumented RFCs

0.1. Document implemented, unstable RFCs

These should be considered the highest priority for documentation, as these are issues which fall under the rest of the rules of [RFC #1636], in that they need to be documented before stabilization. (That will presumably just happen before stabilizing as usual, but I'm including them here for completeness.)

• #0086 plugin-registrar API
• #0202: subslice syntax change -- implemented here, not stabilized; see discussion of [Expand documentation on procedural macros #405] below under C.0.2.
• #1131: Add an expect intrinsic
• #1358: repr_align – implementation is in-progress, not yet landed on nightly
• #1624: loop_break_value
• #1665: Windows subsystem support

0.2. Track accepted, not-yet-implemented or implementation-in-progress, undocumented RFCs

These will eventually require documentation, but as they aren't even (fully) implemented yet, there is no urgency here.

• #0066: Better temporary lifetimes – tracking issue
• #0495: Array/slice/subslice pattern adjustments – tracking issue
• #0803: type ascription on expressions – tracking issue
• #1199: SIMD infrastructure (Note: this is stalled; it may eventually be superceded by a further RFC.)
• #1214: Projections, lifetimes, and well-formed-ness
• #1398: Standard and custom allocator API – tracking issue
• #1432: {Vec,String}::splice – tracking issue
• #1566: Procedural macros – tracking issue
• #1576: literal fragment specifier for macro_rules! – tracking issue
• #1590: lifetime specifier for macro_rules – tracking issue
• #1845: shared_from_slice – tracking issue
• #1860: add ManuallyDrop to core – tracking issue
• #1869: eprint! and eprintln! – tracking issue
• #1884: unstable sort in libcore – tracking issue

1. List accepted, implemented, already-stabilized, undocumented RFCs

This list can be added directly to a newly(-to-be)-created appendix to the Reference.

• Create the appendix (once finished, this list should do just fine, perhaps with some massaging for descriptiveness)

  • #0040: libstd-facade – there is one reference to the facade, in 6.3.13 Compiler Features under a discussion of #[no_std], but no explanation of its meaning. Nor, as far as I can tell, do the relevant sections of the standard library documentation explain this.
  • #0048: Trait reform – some pieces of this are partially documented (the use of Self), but others aren't at all: coherence and orphan rules are covered nowhere. (Currently, the writeup here seems to be the best source on coherence?)
  • #0049: Allow attributes on match arms. – the underlying idea is documented in 6.3 Attributes but the applicability to internal items is never specified.
  • #0131: Some but not all of the flags are documented in 6.3.8 Conditional compilation
  • #0132: Unambiguous function call syntax – not even mentioned
  • #0558: require parentheses for chained comparisons
  • #0560: Integer overflow not unsafe, documented with a reference to the RFC but requires further details
  • #1717: dllimport, one element mentioned but not explained at 6.3.5 FFI attributes
  • #1721: define crt_link
  • #1725: define unaligned_access

2. Write reference material for undocumented, implemented, stabilized RFC features

Each of the features listed above in (1) needs to be documented more formally in the reference.

• #0040: libstd-facade
• #0048: (Document Orphan Rules #5) Trait reform, requires documenting coherence and orphan rules (overlaps with Coherence and Orphan rules below in §3)
• #0049: Allow attributes on match arms: specify applicability to internal items
• [ignore doctest of extern "stdcall" on non-x86 #71]: ([WIP] Expressions rewrite #13) Allow blocks in constants
• #0131: Target specification – some but not all of these are in 6.3.8
• #0132: Unambiguous/universal function call syntax – not even mentioned
• #0179: &mut patterns – symmetry of pattern syntax not documented
• #0558: (Document that parentheses are required for chained comparison operators (RFC 0). #41) require parentheses for chained comparisons – the requirement is not documented in the reference
• #0560: Integer overflow not unsafe, documented with a reference to the RFC but requires further details
• #1717: dllimport
• #1721: crt_link
• #1725: unaligned_access

3. Update out-of-date/incomplete sections of the reference

• List of language items

  The set of language items is currently considered unstable. A complete list of the built-in language items will be added in the future.

• Coherence

• Orphan rules (Document Orphan Rules #5)

• Lifetime elision

D. Documentation not needed

0. Already documented

• #0001: Private fields by default, in 6.2 Visibility and Privacy
• #0003: Rearchitect the attribute-usage lint, in 6.3 Attributes
• #0016: attributes on statements and blocks, in 6.3 Attributes
• #0034: well-formed trait bounds, in 6.1.9 Traits
• #0042: regexp crate – library documented here; could also be treated as Retired since it's currently still part of the nursery and not part of std.
• #0050: adds debug_assert! and assert!; documented at std::debug_assert and std::assert.
• #0060: rename StrBuf to String; documented at std::string::String and collections::string::String.
• #0068: change *T to *const T; documented at 8.1.8 Pointer types
• #0069: add ASCII byte literals and ASCII byte string literals to the language; documented at 3.5.1.3 Byte and byte string literals
• #0079: unspecified layout of structs, documented at 8.1.5 Struct types
• #0109; documented at 5 Crates and source files and used as part of an example in the current Rust book (Custom Allocators)
• #0123: rename Share trait; documented at std::marker::Sync
• #0135: where classes; documented at 6.1.3.1 Generic functions and discussed thoroughly in both the current and upcoming versions of the book.
• #0184: tuple accessors; documented at 8.1.3 Tuple types – may be revised in [WIP] Expressions rewrite #13
• #0214: while letloops; documented at 7.2.24 while let loops.
• #0218: empty struct with braces; documented at both 6.1.5 Structs and 7.2.4 Struct expressions
• #0164: Feature gate pattern-matching on slices; documented as feature-flagged and unstable at 6.3.13 Compiler features.
• #0390: Define variants in a sub-namespace of their enum; clear from all examples at 6.1.6 Enumerations and in the book, and explicit in the discussion of paths in 6.1 Items.
• #0403: Cargo build command—not, strictly speaking, a language detail; and documented in the book and at doc.crates.io.
• #0446: ES6-style unicode string escaping, documented at 3.5.1.1.3 Unicode escapes.
• #0450: Un-feature-gate tuple_indexing, if_let, and while_let, documented at 8.1.3 Tuple types, 7.2.23 if let expressions, 7.2.24 while let loops.
• #0520: Array syntax [T; N] and [x; N], documented in 8.1.4 Array and Slice types.
• #0544: Rename int to usize/isize, documented in 8.1.1.2 Machine-dependent integer types
• #0563: Remove ndebug config variable – replaced with debug_assertions, documented at 6.3.8 Conditional Compilation
• #0565: Renaming fmt::Show and fmt::String to fmt::Debug and fmt::Display respectively, along with where to implement them; documented in the entire standard library as well as specifically at std::fmt::Debug and std::fmt::Display
• #1054: change str::words() to str::split_whitespace(), documented in std
• #1057: add the Sync bound to io::Error, documented at std::io::Error
• #1058: replace slice.tail(), slice.init() with slice.split_first(), slice.split_last(), documented at slice
• #1066: change std::mem::forget not to be unsafe (though it is not safe), behavior is carefully and fully documented at std::mem::forget
• #1102: replace SliceConcatExt::connect with SliceConcatExt::join, documented in std
• #1119: add result::Result::expect() method, documented in std
• #1123: add str::split_at() method, documented in std
• #1618: relax format_args! type restrictions, documented in std
• #1620: regex-1.0, documented in-tree at the crate docs (this is a library issue, not a reference issue)
• #1640: duration_checked, documented in std

1. Retired

These items were accepted, but never implemented and not currently *planned* to be implemented and therefore not in need of documentation.

• #0008: New intrinsics
• #0112: Remove cross borrowing coercion. Replaced by the removal in #0139.
• #0115: do not fall back to int if cannot infer integer; replaced with #0212.
• #0155: only allow "anonymous impl" (impl Foo) in the same module as the data type is defined (struct Foo or mod Foo). Replaced by #0735.

2. Removals

Some items constitute not *additions to be documented* but *things removed* from the language. These do not require documentation (for obvious reasons!).

• #0026: Remove the priv keyword
• #0059: Remove ~ in favor of box and Box
• #0063: Tighten restrictions on mod
• #0093: Remove localization from format!
• #0139: Remove cross borrowing entirely.
• #0230: Remove runtime
• #0256: Remove refcounting Gc<T> from stdlib
• #0341: Remove "virtual struct"/struct inheritance feature
• #0379: Remove reflection (libdebug, Poly trait, and an earlier version of :?, since repurposed)
• #0385: Module system cleanup and simplification (current module rules are documented; these changes removed restrictions)
• #0533: Remove support for moving individual elements into uninitialized arrays or out of fixed-sized arrays
• #1096: Remove static_assert

3. Parser-specific

Some changes are specific to the parsing (though they affect the language). These should be documented not in the reference but in the language grammar.

• #0092: struct grammar change/simplification (may also be touched in [WIP] Expressions rewrite #13)
• #0342: keywords, listed in the grammar and linked explicitly at 2.2 String table productions

4. Process and conventions

• #0199: Conventions for ownership variants (naming conventions, mostly internal interest)
• #0235: Conventions for collections and iterables (and a few other things)
• #0236: Conventions for error handling
• #0240: Conventions for unsafe API locations
• #0344: Conventions for naming conventions: types in method names, iterator type names, iterator method names, getter/setter APIs, associated types, traits, lints, suffix ordering, and prelude traits.
• #0356: Conventions for exported items (Io:Error, not Io::IoError)
• #0430: Conventions for capitalization, underscores, and unwrap
• #0445: Conventions for naming extension traits
• #0505: Conventions for API docs for Rust projects (including the language)
• #0507: Release channels
• #0531: RFC scope and Rust "distribution" definition
• #0556: Conventions for unsafe functions constructing references out of raw pointers
• #1068: Scaling Rust's governance
• #1105: API evolution and versioning guidelines
• #1122: Rust language SemVer definitions
• #1242: Policy for rust-lang GitHub organization crates governance
• #1331: grammar: make the formal grammer canonical and formal – Note: I think this should probably be linked in the reference (as well as other places) once it's finished, and it's already linked from the head of the reference.
• #1567: Normalize long error codes with a baseline template
• #1574: More API Documentation Conventions
• #1589: Define the rustc bugfix best practices
• #1607: RFC process for formatting style and Rustfmt defaults (results will be captured in a non-reference document)
• #1636: Document All Features (process) (this PR!)
• #1643: Dedicated strike team to resolve unsafe code guidelines (results should be captured in the Reference, but this issue itself not so much)
• #1644: Default and expanded errors for rustc
• #1683: Create a docs subteam
• #1728: North Star (process)
• #1774: Roadmap for 2017
• #1828: Rust bookshelf

5. Non-language features

• #1317: Rust Language Server

---

Note: I've just copied over the original issue as it was—wholesale. Note that some of the links here referencing things as "already documented" will degrade given the new structure of the book.

[mattico]

Also needs documenting: #[cfg(target_feature = "")]. I'll get around to it if I don't forget.

[chriskrycho]

Sorry it took me so long to respond, @mattico—thanks for the note! I'll flag it as something to do when adding the other similar configurable compilation bits with e.g. #0131.

[mrhota]

Would it be useful to have a link in the nightly lang reference to this issue?

[steveklabnik]

@mrhota that's a great idea!

[Eh2406]

Note for anyone viewing this page there is a long list of RFC that still need the documentation status evaluated. I am happy to merge changes from forks of the gist.

[chriskrycho]

Even simpler, let's have interested people fork my new copy of the original (for which a thousand thanks, @Eh2406!) and I can more easily merge them and track them myself!

[chriskrycho]

Update to above comment, @mattico: target_feature will be covered in #1199!

[sunjay]

Could you add something in the description for those of us who want to help but don't know what you want us to do? Right now all I see is a big list of stuff but I'm not sure what you want us to help with and how exactly you want us to go about it. This is a very monolithic issue and it's hard to know what to do if you haven't helped with this kind of thing before.