//! List of the removed feature gates. use super::{to_nonzero, Feature}; use rustc_span::symbol::sym; pub struct RemovedFeature { pub feature: Feature, pub reason: Option<&'static str>, } macro_rules! declare_features { ($( $(#[doc = $doc:tt])* (removed, $feature:ident, $ver:expr, $issue:expr, $reason:expr), )+) => { /// Formerly unstable features that have now been removed. pub const REMOVED_FEATURES: &[RemovedFeature] = &[ $(RemovedFeature { feature: Feature { name: sym::$feature, since: $ver, issue: to_nonzero($issue), }, reason: $reason }),+ ]; }; } #[rustfmt::skip] declare_features! ( // ------------------------------------------------------------------------- // feature-group-start: removed features // ------------------------------------------------------------------------- (removed, advanced_slice_patterns, "1.0.0", Some(62254), Some("merged into `#![feature(slice_patterns)]`")), (removed, allocator, "1.0.0", None, None), /// Allows a test to fail without failing the whole suite. (removed, allow_fail, "1.19.0", Some(46488), Some("removed due to no clear use cases")), (removed, await_macro, "1.38.0", Some(50547), Some("subsumed by `.await` syntax")), /// Allows using the `box $expr` syntax. (removed, box_syntax, "1.70.0", Some(49733), Some("replaced with `#[rustc_box]`")), /// Allows capturing disjoint fields in a closure/coroutine (RFC 2229). (removed, capture_disjoint_fields, "1.49.0", Some(53488), Some("stabilized in Rust 2021")), /// Allows comparing raw pointers during const eval. (removed, const_compare_raw_pointers, "1.46.0", Some(53020), Some("cannot be allowed in const eval in any meaningful way")), /// Allows limiting the evaluation steps of const expressions (removed, const_eval_limit, "1.43.0", Some(67217), Some("removed the limit entirely")), /// Allows non-trivial generic constants which have to be manually propagated upwards. (removed, const_evaluatable_checked, "1.48.0", Some(76560), Some("renamed to `generic_const_exprs`")), /// Allows the definition of `const` functions with some advanced features. (removed, const_fn, "1.54.0", Some(57563), Some("split into finer-grained feature gates")), /// Allows const generic types (e.g. `struct Foo(...);`). (removed, const_generics, "1.34.0", Some(44580), Some("removed in favor of `#![feature(adt_const_params)]` and `#![feature(generic_const_exprs)]`")), /// Allows `[x; N]` where `x` is a constant (RFC 2203). (removed, const_in_array_repeat_expressions, "1.37.0", Some(49147), Some("removed due to causing promotable bugs")), /// Allows casting raw pointers to `usize` during const eval. (removed, const_raw_ptr_to_usize_cast, "1.55.0", Some(51910), Some("at compile-time, pointers do not have an integer value, so these casts cannot be properly supported")), /// Allows `T: ?const Trait` syntax in bounds. (removed, const_trait_bound_opt_out, "1.42.0", Some(67794), Some("Removed in favor of `~const` bound in #![feature(const_trait_impl)]")), /// Allows using `crate` as visibility modifier, synonymous with `pub(crate)`. (removed, crate_visibility_modifier, "1.63.0", Some(53120), Some("removed in favor of `pub(crate)`")), /// Allows using custom attributes (RFC 572). (removed, custom_attribute, "1.0.0", Some(29642), Some("removed in favor of `#![register_tool]` and `#![register_attr]`")), /// Allows the use of `#[derive(Anything)]` as sugar for `#[derive_Anything]`. (removed, custom_derive, "1.32.0", Some(29644), Some("subsumed by `#[proc_macro_derive]`")), /// Allows using `#[doc(keyword = "...")]`. (removed, doc_keyword, "1.28.0", Some(51315), Some("merged into `#![feature(rustdoc_internals)]`")), /// Allows using `doc(primitive)` without a future-incompat warning. (removed, doc_primitive, "1.56.0", Some(88070), Some("merged into `#![feature(rustdoc_internals)]`")), /// Allows `#[doc(spotlight)]`. /// The attribute was renamed to `#[doc(notable_trait)]` /// and the feature to `doc_notable_trait`. (removed, doc_spotlight, "1.22.0", Some(45040), Some("renamed to `doc_notable_trait`")), /// Allows using `#[unsafe_destructor_blind_to_params]` (RFC 1238). (removed, dropck_parametricity, "1.38.0", Some(28498), None), /// Allows defining `existential type`s. (removed, existential_type, "1.38.0", Some(63063), Some("removed in favor of `#![feature(type_alias_impl_trait)]`")), /// Paths of the form: `extern::foo::bar` (removed, extern_in_paths, "1.33.0", Some(55600), Some("subsumed by `::foo::bar` paths")), /// Allows `#[doc(include = "some-file")]`. (removed, external_doc, "1.54.0", Some(44732), Some("use #[doc = include_str!(\"filename\")] instead, which handles macro invocations")), /// Allows generators to be cloned. (removed, generator_clone, "1.65.0", Some(95360), Some("renamed to `coroutine_clone`")), /// Allows defining generators. (removed, generators, "1.21.0", Some(43122), Some("renamed to `coroutines`")), /// Allows `impl Trait` in bindings (`let`, `const`, `static`). (removed, impl_trait_in_bindings, "1.55.0", Some(63065), Some("the implementation was not maintainable, the feature may get reintroduced once the current refactorings are done")), (removed, import_shadowing, "1.0.0", None, None), /// Allows in-band quantification of lifetime bindings (e.g., `fn foo(x: &'a u8) -> &'a u8`). (removed, in_band_lifetimes, "1.23.0", Some(44524), Some("removed due to unsolved ergonomic questions and added lifetime resolution complexity")), /// Allows inferring `'static` outlives requirements (RFC 2093). (removed, infer_static_outlives_requirements, "1.63.0", Some(54185), Some("removed as it caused some confusion and discussion was inactive for years")), /// Lazily evaluate constants. This allows constants to depend on type parameters. (removed, lazy_normalization_consts, "1.46.0", Some(72219), Some("superseded by `generic_const_exprs`")), /// Allows using the `#[link_args]` attribute. (removed, link_args, "1.53.0", Some(29596), Some("removed in favor of using `-C link-arg=ARG` on command line, \ which is available from cargo build scripts with `cargo:rustc-link-arg` now")), (removed, macro_reexport, "1.0.0", Some(29638), Some("subsumed by `pub use`")), /// Allows using `#[main]` to replace the entrypoint `#[lang = "start"]` calls. (removed, main, "1.53.0", Some(29634), None), (removed, managed_boxes, "1.0.0", None, None), /// Allows the use of type alias impl trait in function return positions (removed, min_type_alias_impl_trait, "1.56.0", Some(63063), Some("removed in favor of full type_alias_impl_trait")), (removed, needs_allocator, "1.4.0", Some(27389), Some("subsumed by `#![feature(allocator_internals)]`")), /// Allows use of unary negate on unsigned integers, e.g., -e for e: u8 (removed, negate_unsigned, "1.0.0", Some(29645), None), /// Allows `#[no_coverage]` on functions. /// The feature was renamed to `coverage_attribute` and the attribute to `#[coverage(on|off)]` (removed, no_coverage, "1.74.0", Some(84605), Some("renamed to `coverage_attribute`")), /// Allows `#[no_debug]`. (removed, no_debug, "1.43.0", Some(29721), Some("removed due to lack of demand")), /// Note: this feature was previously recorded in a separate /// `STABLE_REMOVED` list because it, uniquely, was once stable but was /// then removed. But there was no utility storing it separately, so now /// it's in this list. (removed, no_stack_check, "1.0.0", None, None), /// Allows using `#[on_unimplemented(..)]` on traits. /// (Moved to `rustc_attrs`.) (removed, on_unimplemented, "1.40.0", None, None), /// A way to temporarily opt out of opt-in copy. This will *never* be accepted. (removed, opt_out_copy, "1.0.0", None, None), /// Allows features specific to OIBIT (now called auto traits). /// Renamed to `auto_traits`. (removed, optin_builtin_traits, "1.0.0", Some(13231), Some("renamed to `auto_traits`")), /// Allows overlapping impls of marker traits. (removed, overlapping_marker_traits, "1.42.0", Some(29864), Some("removed in favor of `#![feature(marker_trait_attr)]`")), (removed, panic_implementation, "1.28.0", Some(44489), Some("subsumed by `#[panic_handler]`")), /// Allows using `#![plugin(myplugin)]`. (removed, plugin, "1.75.0", Some(29597), Some("plugins are no longer supported")), /// Allows using `#[plugin_registrar]` on functions. (removed, plugin_registrar, "1.54.0", Some(29597), Some("plugins are no longer supported")), /// Allows exhaustive integer pattern matching with `usize::MAX`/`isize::MIN`/`isize::MAX`. (removed, precise_pointer_size_matching, "1.32.0", Some(56354), Some("removed in favor of half-open ranges")), (removed, proc_macro_expr, "1.27.0", Some(54727), Some("subsumed by `#![feature(proc_macro_hygiene)]`")), (removed, proc_macro_gen, "1.27.0", Some(54727), Some("subsumed by `#![feature(proc_macro_hygiene)]`")), (removed, proc_macro_mod, "1.27.0", Some(54727), Some("subsumed by `#![feature(proc_macro_hygiene)]`")), (removed, proc_macro_non_items, "1.27.0", Some(54727), Some("subsumed by `#![feature(proc_macro_hygiene)]`")), (removed, pub_macro_rules, "1.53.0", Some(78855), Some("removed due to being incomplete, in particular it does not work across crates")), (removed, pushpop_unsafe, "1.2.0", None, None), (removed, quad_precision_float, "1.0.0", None, None), (removed, quote, "1.33.0", Some(29601), None), (removed, reflect, "1.0.0", Some(27749), None), /// Allows using the `#[register_attr]` attribute. (removed, register_attr, "1.65.0", Some(66080), Some("removed in favor of `#![register_tool]`")), (removed, rust_2018_preview, "1.76.0", None, Some("2018 Edition preview is no longer relevant")), /// Allows using the macros: /// + `__diagnostic_used` /// + `__register_diagnostic` /// +`__build_diagnostic_array` (removed, rustc_diagnostic_macros, "1.38.0", None, None), /// Allows identifying crates that contain sanitizer runtimes. (removed, sanitizer_runtime, "1.17.0", None, None), (removed, simd, "1.0.0", Some(27731), Some("removed in favor of `#[repr(simd)]`")), /// Allows `#[link(kind = "static-nobundle", ...)]`. (removed, static_nobundle, "1.16.0", Some(37403), Some(r#"subsumed by `#[link(kind = "static", modifiers = "-bundle", ...)]`"#)), (removed, struct_inherit, "1.0.0", None, None), (removed, test_removed_feature, "1.0.0", None, None), /// Allows using items which are missing stability attributes (removed, unmarked_api, "1.0.0", None, None), (removed, unsafe_no_drop_flag, "1.0.0", None, None), /// Allows `union` fields that don't implement `Copy` as long as they don't have any drop glue. (removed, untagged_unions, "1.13.0", Some(55149), Some("unions with `Copy` and `ManuallyDrop` fields are stable; there is no intent to stabilize more")), /// Allows `#[unwind(..)]`. /// /// Permits specifying whether a function should permit unwinding or abort on unwind. (removed, unwind_attributes, "1.56.0", Some(58760), Some("use the C-unwind ABI instead")), (removed, visible_private_types, "1.0.0", None, None), // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way. // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! // ------------------------------------------------------------------------- // feature-group-end: removed features // ------------------------------------------------------------------------- );