我在哪里可以找到可以激活的夜间可用功能的最新列表？
示例：
#![feature(plugin_registrar, rustc_private)]
答案 0 :(得分：8)
我不知道某个地方是否有官方文件清单，但在这种情况下，没有比查看at the source code（或current master branch）更好的了。主动功能包括：
declare_features! (
(active, asm, "1.0.0", Some(29722), None),
(active, concat_idents, "1.0.0", Some(29599), None),
(active, link_args, "1.0.0", Some(29596), None),
(active, log_syntax, "1.0.0", Some(29598), None),
(active, non_ascii_idents, "1.0.0", Some(55467), None),
(active, plugin_registrar, "1.0.0", Some(29597), None),
(active, thread_local, "1.0.0", Some(29594), None),
(active, trace_macros, "1.0.0", Some(29598), None),
// rustc internal, for now
(active, intrinsics, "1.0.0", None, None),
(active, lang_items, "1.0.0", None, None),
(active, format_args_nl, "1.29.0", None, None),
(active, link_llvm_intrinsics, "1.0.0", Some(29602), None),
(active, linkage, "1.0.0", Some(29603), None),
// rustc internal
(active, rustc_diagnostic_macros, "1.0.0", None, None),
(active, rustc_const_unstable, "1.0.0", None, None),
(active, box_syntax, "1.0.0", Some(49733), None),
(active, unboxed_closures, "1.0.0", Some(29625), None),
(active, fundamental, "1.0.0", Some(29635), None),
(active, main, "1.0.0", Some(29634), None),
(active, needs_allocator, "1.4.0", Some(27389), None),
(active, on_unimplemented, "1.0.0", Some(29628), None),
(active, plugin, "1.0.0", Some(29597), None),
(active, simd_ffi, "1.0.0", Some(27731), None),
(active, start, "1.0.0", Some(29633), None),
(active, structural_match, "1.8.0", Some(31434), None),
(active, panic_runtime, "1.10.0", Some(32837), None),
(active, needs_panic_runtime, "1.10.0", Some(32837), None),
// Features specific to OIBIT (auto traits)
(active, optin_builtin_traits, "1.0.0", Some(13231), None),
// Allows `#[staged_api]`.
//
// rustc internal
(active, staged_api, "1.0.0", None, None),
// Allows `#![no_core]`.
(active, no_core, "1.3.0", Some(29639), None),
// Allows the use of `box` in patterns (RFC 469).
(active, box_patterns, "1.0.0", Some(29641), None),
// Allows the use of the `unsafe_destructor_blind_to_params` attribute (RFC 1238).
(active, dropck_parametricity, "1.3.0", Some(28498), None),
// Allows using the `may_dangle` attribute (RFC 1327).
(active, dropck_eyepatch, "1.10.0", Some(34761), None),
// Allows the use of custom attributes (RFC 572).
(active, custom_attribute, "1.0.0", Some(29642), None),
// Allows the use of `rustc_*` attributes (RFC 572).
(active, rustc_attrs, "1.0.0", Some(29642), None),
// Allows the use of non lexical lifetimes (RFC 2094).
(active, nll, "1.0.0", Some(43234), None),
// Allows the use of `#[allow_internal_unstable]`. This is an
// attribute on `macro_rules!` and can't use the attribute handling
// below (it has to be checked before expansion possibly makes
// macros disappear).
//
// rustc internal
(active, allow_internal_unstable, "1.0.0", None, None),
// Allows the use of `#[allow_internal_unsafe]`. This is an
// attribute on `macro_rules!` and can't use the attribute handling
// below (it has to be checked before expansion possibly makes
// macros disappear).
//
// rustc internal
(active, allow_internal_unsafe, "1.0.0", None, None),
// Allows the use of slice patterns (issue #23121).
(active, slice_patterns, "1.0.0", Some(23121), None),
// Allows the definition of `const` functions with some advanced features.
(active, const_fn, "1.2.0", Some(57563), None),
// Allows accessing fields of unions inside `const` functions.
(active, const_fn_union, "1.27.0", Some(51909), None),
// Allows casting raw pointers to `usize` during const eval.
(active, const_raw_ptr_to_usize_cast, "1.27.0", Some(51910), None),
// Allows dereferencing raw pointers during const eval.
(active, const_raw_ptr_deref, "1.27.0", Some(51911), None),
// Allows reinterpretation of the bits of a value of one type as another type during const eval.
(active, const_transmute, "1.29.0", Some(53605), None),
// Allows comparing raw pointers during const eval.
(active, const_compare_raw_pointers, "1.27.0", Some(53020), None),
// Allows panicking during const eval (producing compile-time errors).
(active, const_panic, "1.30.0", Some(51999), None),
// Allows using `#[prelude_import]` on glob `use` items.
//
// rustc internal
(active, prelude_import, "1.2.0", None, None),
// Allows default type parameters to influence type inference.
(active, default_type_parameter_fallback, "1.3.0", Some(27336), None),
// Allows associated type defaults.
(active, associated_type_defaults, "1.2.0", Some(29661), None),
// Allows `repr(simd)` and importing the various simd intrinsics.
(active, repr_simd, "1.4.0", Some(27731), None),
// Allows `extern "platform-intrinsic" { ... }`.
(active, platform_intrinsics, "1.4.0", Some(27731), None),
// Allows `#[unwind(..)]`.
//
// Permits specifying whether a function should permit unwinding or abort on unwind.
(active, unwind_attributes, "1.4.0", Some(58760), None),
// Allows the use of `#[naked]` on functions.
(active, naked_functions, "1.9.0", Some(32408), None),
// Allows `#[no_debug]`.
(active, no_debug, "1.5.0", Some(29721), None),
// Allows `#[omit_gdb_pretty_printer_section]`.
//
// rustc internal
(active, omit_gdb_pretty_printer_section, "1.5.0", None, None),
// Allows attributes on expressions and non-item statements.
(active, stmt_expr_attributes, "1.6.0", Some(15701), None),
// Allows the use of type ascription in expressions.
(active, type_ascription, "1.6.0", Some(23416), None),
// Allows `cfg(target_thread_local)`.
(active, cfg_target_thread_local, "1.7.0", Some(29594), None),
// rustc internal
(active, abi_vectorcall, "1.7.0", None, None),
// Allows `X..Y` patterns.
(active, exclusive_range_pattern, "1.11.0", Some(37854), None),
// impl specialization (RFC 1210)
(active, specialization, "1.7.0", Some(31844), None),
// Allows `cfg(target_has_atomic = "...")`.
(active, cfg_target_has_atomic, "1.9.0", Some(32976), None),
// The `!` type. Does not imply 'exhaustive_patterns' (below) any more.
(active, never_type, "1.13.0", Some(35121), None),
// Allows exhaustive pattern matching on types that contain uninhabited types.
(active, exhaustive_patterns, "1.13.0", Some(51085), None),
// Allows untagged unions `union U { ... }`.
(active, untagged_unions, "1.13.0", Some(32836), None),
// Used to identify the `compiler_builtins` crate.
//
// rustc internal.
(active, compiler_builtins, "1.13.0", None, None),
// Allows `#[link(..., cfg(..))]`.
(active, link_cfg, "1.14.0", Some(37406), None),
// Allows `extern "ptx-*" fn()`.
(active, abi_ptx, "1.15.0", Some(38788), None),
// The `repr(i128)` annotation for enums.
(active, repr128, "1.16.0", Some(35118), None),
// Allows the use of `#[ffi_returns_twice]` on foreign functions.
(active, ffi_returns_twice, "1.34.0", Some(58314), None),
// The `unadjusted` ABI; perma-unstable.
//
// rustc internal
(active, abi_unadjusted, "1.16.0", None, None),
// Declarative macros 2.0 (`macro`).
(active, decl_macro, "1.17.0", Some(39412), None),
// Allows `#[link(kind="static-nobundle"...)]`.
(active, static_nobundle, "1.16.0", Some(37403), None),
// Allows `extern "msp430-interrupt" fn()`.
(active, abi_msp430_interrupt, "1.16.0", Some(38487), None),
// Used to identify crates that contain sanitizer runtimes.
//
// rustc internal
(active, sanitizer_runtime, "1.17.0", None, None),
// Used to identify crates that contain the profiler runtime.
//
// rustc internal
(active, profiler_runtime, "1.18.0", None, None),
// Allows `extern "x86-interrupt" fn()`.
(active, abi_x86_interrupt, "1.17.0", Some(40180), None),
// Allows the `try {...}` expression.
(active, try_blocks, "1.29.0", Some(31436), None),
// Allows module-level inline assembly by way of `global_asm!()`.
(active, global_asm, "1.18.0", Some(35119), None),
// Allows overlapping impls of marker traits.
(active, overlapping_marker_traits, "1.18.0", Some(29864), None),
// Trait attribute to allow overlapping impls.
(active, marker_trait_attr, "1.30.0", Some(29864), None),
// rustc internal
(active, abi_thiscall, "1.19.0", None, None),
// Allows a test to fail without failing the whole suite.
(active, allow_fail, "1.19.0", Some(46488), None),
// Allows unsized tuple coercion.
(active, unsized_tuple_coercion, "1.20.0", Some(42877), None),
// Generators
(active, generators, "1.21.0", Some(43122), None),
// Trait aliases
(active, trait_alias, "1.24.0", Some(41517), None),
// rustc internal
(active, allocator_internals, "1.20.0", None, None),
// `#[doc(cfg(...))]`
(active, doc_cfg, "1.21.0", Some(43781), None),
// `#[doc(masked)]`
(active, doc_masked, "1.21.0", Some(44027), None),
// `#[doc(spotlight)]`
(active, doc_spotlight, "1.22.0", Some(45040), None),
// `#[doc(include = "some-file")]`
(active, external_doc, "1.22.0", Some(44732), None),
// Future-proofing enums/structs with `#[non_exhaustive]` attribute (RFC 2008).
(active, non_exhaustive, "1.22.0", Some(44109), None),
// Adds `crate` as visibility modifier, synonymous with `pub(crate)`.
(active, crate_visibility_modifier, "1.23.0", Some(53120), None),
// extern types
(active, extern_types, "1.23.0", Some(43467), None),
// Allows trait methods with arbitrary self types.
(active, arbitrary_self_types, "1.23.0", Some(44874), None),
// In-band lifetime bindings (e.g., `fn foo(x: &'a u8) -> &'a u8`).
(active, in_band_lifetimes, "1.23.0", Some(44524), None),
// Generic associated types (RFC 1598)
(active, generic_associated_types, "1.23.0", Some(44265), None),
// Infer static outlives requirements (RFC 2093).
(active, infer_static_outlives_requirements, "1.26.0", Some(54185), None),
// Allows macro invocations in `extern {}` blocks.
(active, macros_in_extern, "1.27.0", Some(49476), None),
// `existential type`
(active, existential_type, "1.28.0", Some(34511), None),
// unstable `#[target_feature]` directives
(active, arm_target_feature, "1.27.0", Some(44839), None),
(active, aarch64_target_feature, "1.27.0", Some(44839), None),
(active, hexagon_target_feature, "1.27.0", Some(44839), None),
(active, powerpc_target_feature, "1.27.0", Some(44839), None),
(active, mips_target_feature, "1.27.0", Some(44839), None),
(active, avx512_target_feature, "1.27.0", Some(44839), None),
(active, mmx_target_feature, "1.27.0", Some(44839), None),
(active, sse4a_target_feature, "1.27.0", Some(44839), None),
(active, tbm_target_feature, "1.27.0", Some(44839), None),
(active, wasm_target_feature, "1.30.0", Some(44839), None),
(active, adx_target_feature, "1.32.0", Some(44839), None),
(active, cmpxchg16b_target_feature, "1.32.0", Some(44839), None),
(active, movbe_target_feature, "1.34.0", Some(44839), None),
// Allows macro invocations on modules expressions and statements and
// procedural macros to expand to non-items.
(active, proc_macro_hygiene, "1.30.0", Some(54727), None),
// `#[doc(alias = "...")]`
(active, doc_alias, "1.27.0", Some(50146), None),
// inconsistent bounds in where clauses
(active, trivial_bounds, "1.28.0", Some(48214), None),
// `'a: { break 'a; }`
(active, label_break_value, "1.28.0", Some(48594), None),
// Exhaustive pattern matching on `usize` and `isize`.
(active, precise_pointer_size_matching, "1.32.0", Some(56354), None),
// `#[doc(keyword = "...")]`
(active, doc_keyword, "1.28.0", Some(51315), None),
// Allows async and await syntax.
(active, async_await, "1.28.0", Some(50547), None),
// `#[alloc_error_handler]`
(active, alloc_error_handler, "1.29.0", Some(51540), None),
(active, abi_amdgpu_kernel, "1.29.0", Some(51575), None),
// Added for testing E0705; perma-unstable.
(active, test_2018_feature, "1.31.0", Some(0), Some(Edition::Edition2018)),
// Allows unsized rvalues at arguments and parameters.
(active, unsized_locals, "1.30.0", Some(48055), None),
// `#![test_runner]`
// `#[test_case]`
(active, custom_test_frameworks, "1.30.0", Some(50297), None),
// non-builtin attributes in inner attribute position
(active, custom_inner_attributes, "1.30.0", Some(54726), None),
// Allow mixing of bind-by-move in patterns and references to
// those identifiers in guards, *if* we are using MIR-borrowck
// (aka NLL). Essentially this means you need to be using the
// 2018 edition or later.
(active, bind_by_move_pattern_guards, "1.30.0", Some(15287), None),
// Allows `impl Trait` in bindings (`let`, `const`, `static`).
(active, impl_trait_in_bindings, "1.30.0", Some(34511), None),
// Allows `const _: TYPE = VALUE`.
(active, underscore_const_names, "1.31.0", Some(54912), None),
// Adds `reason` and `expect` lint attributes.
(active, lint_reasons, "1.31.0", Some(54503), None),
// Allows paths to enum variants on type aliases.
(active, type_alias_enum_variants, "1.31.0", Some(49683), None),
// Re-Rebalance coherence
(active, re_rebalance_coherence, "1.32.0", Some(55437), None),
// Const generic types.
(active, const_generics, "1.34.0", Some(44580), None),
// #[optimize(X)]
(active, optimize_attribute, "1.34.0", Some(54882), None),
// #[repr(align(X))] on enums
(active, repr_align_enum, "1.34.0", Some(57996), None),
// Allows the use of C-variadics
(active, c_variadic, "1.34.0", Some(44930), None),
);
请注意，其中一些内容属于 rustc 并且不打算使用。
答案 1 :(得分：3)
文件src/libsyntax/feature_gate.rs和reference仅列出编译器功能，但不包括api功能。例如，未列出功能rc_counts。
使用此命令：
ack -h --output '$1' 'unstable\(feature = "(\w+)"' $(ls -d * | grep -v -x test) | sort | uniq
在Rust src目录上，我得到了以下列表：
alloc
alloc_jemalloc
alloc_system
arc_counts
as_unsafe_cell
binary_heap_append
binary_heap_extras
borrow_state
box_heap
btree_append
btree_range
btree_split_off
cell_extras
cell_get_mut
coerce_unsized
collection_placement
collections
collections_bound
collections_range
core_char_ext
core_float
core_intrinsics
core_panic
core_private_bignum
core_private_diy_float
core_slice_ext
core_str_ext
c_void_variant
dec2flt
deque_extras
derive_clone_copy
enumset
error_type_id
exit_status_from
filling_drop
fixed_size_array
float_extras
flt2dec
fmt_flags_align
fmt_internals
fnbox
fn_traits
get_type_id
heap_api
inclusive_range
integer_atomics
int_error_internals
io
io_error_internals
ip
ipv6_to_octets
iter_arith
libstd_io_internals
libstd_sys_internals
libstd_thread_internals
linked_list_contains
linked_list_extras
lookup_host
mpsc_select
nonzero
once_poison
oom
panic_abort
panic_unwind
pattern
peekable_is_empty
placement_in
placement_new_protocol
print
process_exec
pthread_t
rand
range_contains
raw
rc_counts
rc_would_unwrap
reflect_marker
rt
rustc_private
rustdoc
set_stdio
shared
slice_concat_ext
static_condvar
static_mutex
static_rwlock
step_by
step_trait
str_char
str_escape
str_internals
test
thread_local_internals
thread_local_state
try_from
unicode
unique
unsize
vec_deque_contains
zero_one
答案 2 :(得分：2)