Sort and categorize #![feature]s in alloc.

library/alloc/src/lib.rs

@@ -80,87 +80,97 @@
 )]
 #![no_std]
 #![needs_allocator]
-#![warn(deprecated_in_future)]
-#![warn(missing_docs)]
-#![warn(missing_debug_implementations)]
-#![allow(explicit_outlives_requirements)]
+//
+// Lints:
 #![deny(unsafe_op_in_unsafe_fn)]
-#![feature(rustc_allow_const_fn_unstable)]
-#![cfg_attr(not(test), feature(generator_trait))]
-#![cfg_attr(test, feature(test))]
-#![cfg_attr(test, feature(new_uninit))]
+#![warn(deprecated_in_future)]
+#![warn(missing_debug_implementations)]
+#![warn(missing_docs)]
+#![allow(explicit_outlives_requirements)]
+//
+// Library features:
+#![feature(alloc_layout_extra)]
 #![feature(allocator_api)]
 #![feature(array_chunks)]
 #![feature(array_methods)]
 #![feature(array_windows)]
+#![feature(async_stream)]
+#![feature(coerce_unsized)]
+#![cfg_attr(not(no_global_oom_handling), feature(const_btree_new))]
+#![feature(const_cow_is_borrowed)]
+#![feature(core_intrinsics)]
+#![feature(cow_is_borrowed)]
+#![feature(dispatch_from_dyn)]
+#![feature(exact_size_is_empty)]
+#![feature(extend_one)]
+#![feature(fmt_internals)]
+#![feature(fn_traits)]
+#![feature(inplace_iteration)]
+#![feature(iter_advance_by)]
+#![feature(iter_zip)]
+#![feature(layout_for_ptr)]
+#![feature(maybe_uninit_extra)]
+#![feature(maybe_uninit_slice)]
+#![feature(maybe_uninit_uninit_array)]
+#![cfg_attr(test, feature(new_uninit))]
+#![feature(nonnull_slice_from_raw_parts)]
+#![feature(option_result_unwrap_unchecked)]
+#![feature(pattern)]
+#![feature(ptr_internals)]
+#![feature(receiver_trait)]
+#![feature(set_ptr_value)]
+#![feature(slice_group_by)]
+#![feature(slice_partition_dedup)]
+#![feature(slice_ptr_get)]
+#![feature(slice_ptr_len)]
+#![feature(slice_range)]
+#![feature(str_internals)]
+#![feature(trusted_len)]
+#![feature(trusted_random_access)]
+#![feature(try_trait_v2)]
+#![feature(unicode_internals)]
+#![feature(unsize)]
+//
+// Language features:
+#![feature(allocator_internals)]
 #![feature(allow_internal_unstable)]
 #![feature(arbitrary_self_types)]
-#![feature(async_stream)]
+#![feature(associated_type_bounds)]
+#![feature(auto_traits)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 #![feature(cfg_sanitize)]
 #![feature(cfg_target_has_atomic)]
-#![feature(coerce_unsized)]
-#![cfg_attr(not(no_global_oom_handling), feature(const_btree_new))]
 #![feature(const_fn_trait_bound)]
-#![feature(cow_is_borrowed)]
-#![feature(const_cow_is_borrowed)]
 #![feature(const_trait_impl)]
+#![feature(decl_macro)]
 #![feature(destructuring_assignment)]
-#![feature(dispatch_from_dyn)]
-#![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
-#![feature(exact_size_is_empty)]
 #![feature(exclusive_range_pattern)]
-#![feature(extend_one)]
-#![feature(fmt_internals)]
-#![feature(fn_traits)]
 #![feature(fundamental)]
-#![feature(inplace_iteration)]
+#![cfg_attr(not(test), feature(generator_trait))]
+#![feature(lang_items)]
+#![feature(min_specialization)]
+#![feature(negative_impls)]
+#![feature(never_type)]
+#![feature(nll)]
+#![feature(rustc_allow_const_fn_unstable)]
+#![feature(rustc_attrs)]
+#![feature(staged_api)]
+#![cfg_attr(test, feature(test))]
+#![feature(unboxed_closures)]
+#![feature(unsized_fn_params)]
+//
+// Rustdoc features:
+#![feature(doc_cfg)]
+#![cfg_attr(not(bootstrap), feature(doc_cfg_hide))]
 // Technically, this is a bug in rustdoc: rustdoc sees the documentation on `#[lang = slice_alloc]`
 // blocks is for `&[T]`, which also has documentation using this feature in `core`, and gets mad
 // that the feature-gate isn't enabled. Ideally, it wouldn't check for the feature gate for docs
 // from other crates, but since this can only appear for lang items, it doesn't seem worth fixing.
 #![feature(intra_doc_pointers)]
-#![feature(iter_advance_by)]
-#![feature(iter_zip)]
-#![feature(lang_items)]
-#![feature(layout_for_ptr)]
-#![feature(negative_impls)]
-#![feature(never_type)]
-#![feature(nll)]
-#![feature(nonnull_slice_from_raw_parts)]
-#![feature(auto_traits)]
-#![feature(option_result_unwrap_unchecked)]
-#![feature(pattern)]
-#![feature(ptr_internals)]
-#![feature(rustc_attrs)]
-#![feature(receiver_trait)]
-#![feature(min_specialization)]
-#![feature(set_ptr_value)]
-#![feature(slice_ptr_get)]
-#![feature(slice_ptr_len)]
-#![feature(slice_range)]
-#![feature(staged_api)]
-#![feature(str_internals)]
-#![feature(trusted_len)]
-#![feature(unboxed_closures)]
-#![feature(unicode_internals)]
-#![feature(unsize)]
-#![feature(unsized_fn_params)]
-#![feature(allocator_internals)]
-#![feature(slice_partition_dedup)]
-#![feature(maybe_uninit_extra, maybe_uninit_slice, maybe_uninit_uninit_array)]
-#![feature(alloc_layout_extra)]
-#![feature(trusted_random_access)]
-#![feature(try_trait_v2)]
-#![feature(associated_type_bounds)]
-#![feature(slice_group_by)]
-#![feature(decl_macro)]
-#![feature(doc_cfg)]
-#![cfg_attr(not(bootstrap), feature(doc_cfg_hide))]
-// Allow testing this library
 
+// Allow testing this library
 #[cfg(test)]
 #[macro_use]
 extern crate std;