| //! List of the removed feature gates. |
| |
| use std::num::{NonZero, NonZeroU32}; |
| |
| use rustc_span::sym; |
| |
| use super::{Feature, to_nonzero}; |
| |
| pub struct RemovedFeature { |
| pub feature: Feature, |
| pub reason: Option<&'static str>, |
| pub pull: Option<NonZero<u32>>, |
| } |
| |
| macro_rules! opt_nonzero_u32 { |
| () => { |
| None |
| }; |
| ($val:expr) => { |
| Some(NonZeroU32::new($val).unwrap()) |
| }; |
| } |
| |
| macro_rules! declare_features { |
| ($( |
| $(#[doc = $doc:tt])* (removed, $feature:ident, $ver:expr, $issue:expr, $reason:expr $(, $pull:expr)?), |
| )+) => { |
| /// Formerly unstable features that have now been removed. |
| pub static REMOVED_LANG_FEATURES: &[RemovedFeature] = &[ |
| $(RemovedFeature { |
| feature: Feature { |
| name: sym::$feature, |
| since: $ver, |
| issue: to_nonzero($issue), |
| }, |
| reason: $reason, |
| pull: opt_nonzero_u32!($($pull)?), |
| }),+ |
| ]; |
| }; |
| } |
| |
| #[rustfmt::skip] |
| declare_features! ( |
| // ------------------------------------------------------------------------- |
| // feature-group-start: removed features |
| // ------------------------------------------------------------------------- |
| |
| // Note that the version indicates when it got *removed*. |
| // When moving an unstable feature here, set the version number to |
| // `CURRENT RUSTC VERSION` with ` ` replaced by `_`. |
| // (But not all features below do this properly; many indicate the |
| // version they got originally added in.) |
| |
| /// Allows using the `amdgpu-kernel` ABI. |
| (removed, abi_amdgpu_kernel, "1.77.0", Some(51575), None, 120495), |
| (removed, advanced_slice_patterns, "1.42.0", Some(62254), |
| Some("merged into `#![feature(slice_patterns)]`"), 67712), |
| (removed, allocator, "1.0.0", None, None), |
| /// Allows a test to fail without failing the whole suite. |
| (removed, allow_fail, "1.60.0", Some(46488), Some("removed due to no clear use cases"), 93416), |
| (removed, await_macro, "1.38.0", Some(50547), |
| Some("subsumed by `.await` syntax"), 62293), |
| /// Allows using the `box $expr` syntax. |
| (removed, box_syntax, "1.70.0", Some(49733), Some("replaced with `#[rustc_box]`"), 108471), |
| /// Allows capturing disjoint fields in a closure/coroutine (RFC 2229). |
| (removed, capture_disjoint_fields, "1.69.0", Some(53488), Some("stabilized in Rust 2021"), 108550), |
| /// 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"), 73398), |
| /// Allows limiting the evaluation steps of const expressions |
| (removed, const_eval_limit, "1.72.0", Some(67217), Some("removed the limit entirely"), 103877), |
| /// Allows non-trivial generic constants which have to be manually propagated upwards. |
| (removed, const_evaluatable_checked, "1.56.0", Some(76560), Some("renamed to `generic_const_exprs`"), 88369), |
| /// 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"), 85109), |
| /// Allows const generic types (e.g. `struct Foo<const N: usize>(...);`). |
| (removed, const_generics, "1.56.0", Some(44580), |
| Some("removed in favor of `#![feature(adt_const_params)]` and `#![feature(generic_const_exprs)]`"), 88369), |
| /// Allows `[x; N]` where `x` is a constant (RFC 2203). |
| (removed, const_in_array_repeat_expressions, "1.51.0", Some(49147), |
| Some("removed due to causing promotable bugs"), 80404), |
| /// 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"), 87020), |
| /// Allows `T: ?const Trait` syntax in bounds. |
| (removed, const_trait_bound_opt_out, "1.56.0", Some(67794), |
| Some("Removed in favor of `~const` bound in #![feature(const_trait_impl)]"), 88328), |
| /// 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)`"), 97254), |
| /// Allows using custom attributes (RFC 572). |
| (removed, custom_attribute, "1.0.0", Some(29642), |
| Some("removed in favor of `#![register_tool]` and `#![register_attr]`"), 66070), |
| /// 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 default type parameters to influence type inference. |
| (removed, default_type_parameter_fallback, "1.82.0", Some(27336), |
| Some("never properly implemented; requires significant design work"), 127655), |
| /// Allows deriving traits as per `SmartPointer` specification |
| (removed, derive_smart_pointer, "1.84.0", Some(123430), Some("replaced by `CoercePointee`"), 131284), |
| /// Allows using `#[doc(keyword = "...")]`. |
| (removed, doc_keyword, "1.58.0", Some(51315), |
| Some("merged into `#![feature(rustdoc_internals)]`"), 90420), |
| /// Allows using `doc(primitive)` without a future-incompat warning. |
| (removed, doc_primitive, "1.58.0", Some(88070), |
| Some("merged into `#![feature(rustdoc_internals)]`"), 90420), |
| /// Allows `#[doc(spotlight)]`. |
| /// The attribute was renamed to `#[doc(notable_trait)]` |
| /// and the feature to `doc_notable_trait`. |
| (removed, doc_spotlight, "1.53.0", Some(45040), |
| Some("renamed to `doc_notable_trait`"), 80965), |
| /// Allows using `#[unsafe_destructor_blind_to_params]` (RFC 1238). |
| (removed, dropck_parametricity, "1.38.0", Some(28498), None), |
| /// Allows making `dyn Trait` well-formed even if `Trait` is not dyn compatible[^1]. |
| /// In that case, `dyn Trait: Trait` does not hold. Moreover, coercions and |
| /// casts in safe Rust to `dyn Trait` for such a `Trait` is also forbidden. |
| /// |
| /// Renamed from `object_safe_for_dispatch`. |
| /// |
| /// [^1]: Formerly known as "object safe". |
| (removed, dyn_compatible_for_dispatch, "1.87.0", Some(43561), |
| Some("removed, not used heavily and represented additional complexity in dyn compatibility"), 136522), |
| /// Uses generic effect parameters for ~const bounds |
| (removed, effects, "1.84.0", Some(102090), |
| Some("removed, redundant with `#![feature(const_trait_impl)]`"), 132479), |
| /// 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"), 57572), |
| /// Allows `#[doc(include = "some-file")]`. |
| (removed, external_doc, "1.54.0", Some(44732), |
| Some("use #[doc = include_str!(\"filename\")] instead, which handles macro invocations"), 85457), |
| /// Allows using `#[ffi_returns_twice]` on foreign functions. |
| (removed, ffi_returns_twice, "1.78.0", Some(58314), |
| Some("being investigated by the ffi-unwind project group"), 120502), |
| /// Allows generators to be cloned. |
| (removed, generator_clone, "1.75.0", Some(95360), Some("renamed to `coroutine_clone`"), 116958), |
| /// Allows defining generators. |
| (removed, generators, "1.75.0", Some(43122), Some("renamed to `coroutines`"), 116958), |
| /// An extension to the `generic_associated_types` feature, allowing incomplete features. |
| (removed, generic_associated_types_extended, "1.85.0", Some(95451), |
| Some( |
| "feature needs overhaul and reimplementation pending \ |
| better implied higher-ranked implied bounds support" |
| ), |
| 133768 |
| ), |
| (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, "1.61.0", Some(44524), |
| Some("removed due to unsolved ergonomic questions and added lifetime resolution complexity"), 93845), |
| /// 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"), 97875), |
| /// Allow anonymous constants from an inline `const` block in pattern position |
| (removed, inline_const_pat, "1.88.0", Some(76001), |
| Some("removed due to implementation concerns as it requires significant refactorings"), 138492), |
| /// Lazily evaluate constants. This allows constants to depend on type parameters. |
| (removed, lazy_normalization_consts, "1.56.0", Some(72219), Some("superseded by `generic_const_exprs`"), 88369), |
| /// Changes `impl Trait` to capture all lifetimes in scope. |
| (removed, lifetime_capture_rules_2024, "1.87.0", None, Some("unnecessary -- use edition 2024 instead"), 136787), |
| /// 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"), 83820), |
| (removed, macro_reexport, "1.0.0", Some(29638), |
| Some("subsumed by `pub use`"), 49982), |
| /// Allows using `#[main]` to replace the entrypoint `#[lang = "start"]` calls. |
| (removed, main, "1.53.0", Some(29634), None, 84217), |
| (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"), 87564), |
| /// Make `mut` not reset the binding mode on edition >= 2024. |
| (removed, mut_preserve_binding_mode_2024, "1.80.0", Some(123076), Some("superseded by `ref_pat_eat_one_layer_2024`"), 125168), |
| (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`"), 114656), |
| /// Allows `#[no_debug]`. |
| (removed, no_debug, "1.43.0", Some(29721), Some("removed due to lack of demand"), 69667), |
| /// 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, 40110), |
| /// Allows making `dyn Trait` well-formed even if `Trait` is not dyn compatible (object safe). |
| /// Renamed to `dyn_compatible_for_dispatch`. |
| (removed, object_safe_for_dispatch, "1.83.0", Some(43561), |
| Some("renamed to `dyn_compatible_for_dispatch`"), 131511), |
| /// Allows using `#[on_unimplemented(..)]` on traits. |
| /// (Moved to `rustc_attrs`.) |
| (removed, on_unimplemented, "1.40.0", None, None, 65794), |
| /// A way to temporarily opt out of opt-in copy. This will *never* be accepted. |
| (removed, opt_out_copy, "1.0.0", None, None, 20740), |
| /// Allows features specific to OIBIT (now called auto traits). |
| /// Renamed to `auto_traits`. |
| (removed, optin_builtin_traits, "1.50.0", Some(13231), |
| Some("renamed to `auto_traits`"), 79336), |
| /// Allows overlapping impls of marker traits. |
| (removed, overlapping_marker_traits, "1.42.0", Some(29864), |
| Some("removed in favor of `#![feature(marker_trait_attr)]`"), 68544), |
| (removed, panic_implementation, "1.28.0", Some(44489), |
| Some("subsumed by `#[panic_handler]`"), 53619), |
| /// Allows `extern "platform-intrinsic" { ... }`. |
| (removed, platform_intrinsics, "1.78.0", Some(27731), |
| Some("SIMD intrinsics use the regular intrinsics ABI now"), 121516), |
| /// Allows using `#![plugin(myplugin)]`. |
| (removed, plugin, "1.75.0", Some(29597), |
| Some("plugins are no longer supported"), 116412), |
| /// Allows using `#[plugin_registrar]` on functions. |
| (removed, plugin_registrar, "1.75.0", Some(29597), |
| Some("plugins are no longer supported"), 116412), |
| /// Allows exhaustive integer pattern matching with `usize::MAX`/`isize::MIN`/`isize::MAX`. |
| (removed, precise_pointer_size_matching, "1.76.0", Some(56354), |
| Some("removed in favor of half-open ranges"), 118598), |
| (removed, pref_align_of, "1.89.0", Some(91971), |
| Some("removed due to marginal use and inducing compiler complications")), |
| (removed, proc_macro_expr, "1.27.0", Some(54727), |
| Some("subsumed by `#![feature(proc_macro_hygiene)]`"), 52121), |
| (removed, proc_macro_gen, "1.27.0", Some(54727), |
| Some("subsumed by `#![feature(proc_macro_hygiene)]`"), 52121), |
| (removed, proc_macro_mod, "1.27.0", Some(54727), |
| Some("subsumed by `#![feature(proc_macro_hygiene)]`"), 52121), |
| (removed, proc_macro_non_items, "1.27.0", Some(54727), |
| Some("subsumed by `#![feature(proc_macro_hygiene)]`"), 52121), |
| (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, ref_pat_everywhere, "1.80.0", Some(123076), Some("superseded by `ref_pat_eat_one_layer_2024"), 125168), |
| (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]`"), 66070), |
| (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, 64139), |
| /// Allows identifying crates that contain sanitizer runtimes. |
| (removed, sanitizer_runtime, "1.17.0", None, None, 65241), |
| (removed, simd, "1.0.0", Some(27731), Some("removed in favor of `#[repr(simd)]`")), |
| /// Allows using `#[start]` on a function indicating that it is the program entrypoint. |
| (removed, start, "1.86.0", Some(29633), Some("not portable enough and never RFC'd"), 134299), |
| /// Allows `#[link(kind = "static-nobundle", ...)]`. |
| (removed, static_nobundle, "1.63.0", Some(37403), |
| Some(r#"subsumed by `#[link(kind = "static", modifiers = "-bundle", ...)]`"#), 95818), |
| (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), |
| /// Allows unnamed fields of struct and union type |
| (removed, unnamed_fields, "1.83.0", Some(49804), Some("feature needs redesign"), 131045), |
| (removed, unsafe_no_drop_flag, "1.0.0", None, None), |
| /// Allows unsized rvalues at arguments and parameters. |
| (removed, unsized_locals, "1.89.0", Some(48055), Some("removed due to implementation concerns; see https://github.com/rust-lang/rust/issues/111942")), |
| (removed, unsized_tuple_coercion, "1.87.0", Some(42877), |
| Some("The feature restricts possible layouts for tuples, and this restriction is not worth it."), 137728), |
| /// Allows `union` fields that don't implement `Copy` as long as they don't have any drop glue. |
| (removed, untagged_unions, "1.64.0", Some(55149), |
| Some("unions with `Copy` and `ManuallyDrop` fields are stable; there is no intent to stabilize more"), 97995), |
| /// 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"), 86155), |
| (removed, visible_private_types, "1.0.0", None, None), |
| /// Allows `extern "wasm" fn` |
| (removed, wasm_abi, "1.81.0", Some(83788), |
| Some("non-standard wasm ABI is no longer supported"), 127605), |
| // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! |
| // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way. |
| // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! |
| |
| // ------------------------------------------------------------------------- |
| // feature-group-end: removed features |
| // ------------------------------------------------------------------------- |
| ); |
