gate Alloc, Mem, Ptr, Slice, Str unsafe fns with unsafe··

This way they can be more flexibly used from other modules.

- fix build with just `unsafe_layout`.
- misc. doc updates.

src/sys/env/namespace.rs

@@ -77,6 +77,7 @@ impl Env {
     /// # Safety
     /// See [remove_var].
     #[cfg(all(not(feature = "safe_sys"), feature = "unsafe_thread"))]
+    #[cfg_attr(feature = "nightly_doc", doc(cfg(feature = "unsafe_thread")))]
     pub unsafe fn remove_var<K: AsRef<OsStr>>(key: K) {
         unsafe { remove_var(key) }
     }
@@ -87,6 +88,7 @@ impl Env {
     /// # Safety
     /// See [set_var].
     #[cfg(all(not(feature = "safe_sys"), feature = "unsafe_thread"))]
+    #[cfg_attr(feature = "nightly_doc", doc(cfg(feature = "unsafe_thread")))]
     pub unsafe fn set_var<K: AsRef<OsStr>, V: AsRef<OsStr>>(key: K, value: V) {
         unsafe { set_var(key, value) }
     }

src/sys/mem/alloc/namespace.rs

@@ -29,8 +29,12 @@ impl Alloc {
     }
 }
 
-#[cfg_attr(feature = "nightly_doc", doc(cfg(feature = "unsafe_layout")))]
-#[cfg(all(not(feature = "safe_mem"), feature = "unsafe_layout"))]
+/// # Unsafe methods
+///
+/// ## Features
+/// They depend on enabling any `unsafe*` feature, and not enabling `safe_mem`.
+#[cfg_attr(feature = "nightly_doc", doc(cfg(unsafe··)))]
+#[cfg(all(not(feature = "safe_mem"), unsafe··))]
 #[cfg_attr(feature = "nightly_doc", doc(cfg(feature = "alloc")))]
 #[cfg(feature = "alloc")]
 #[rustfmt::skip]

src/sys/mem/namespace.rs

@@ -126,9 +126,12 @@ impl Mem {
     }
 }
 
-/// # Unsafe methods gated by `unsafe_layout`
-#[cfg_attr(feature = "nightly_doc", doc(cfg(feature = "unsafe_layout")))]
-#[cfg(all(not(feature = "safe_mem"), feature = "unsafe_layout"))]
+/// # Unsafe methods
+///
+/// ## Features
+/// They depend on enabling any `unsafe*` feature, and not enabling `safe_mem`.
+#[cfg_attr(feature = "nightly_doc", doc(cfg(unsafe··)))]
+#[cfg(all(not(feature = "safe_mem"), unsafe··))]
 impl Mem {
     // NOTE: can't compile, errors with: error[E0512]:
     // cannot transmute between types of different sizes, or dependently-sized types

src/sys/mem/ptr/namespace.rs

@@ -230,10 +230,13 @@ impl Ptr {
     }
 }
 
-/// # Unsafe methods gated by `unsafe_ptr`
+/// # Unsafe methods
+///
+/// ## Features
+/// They depend on enabling any `unsafe*` feature, and not enabling `safe_mem`.
 #[rustfmt::skip]
-#[cfg_attr(feature = "nightly_doc", doc(cfg(feature = "unsafe_ptr")))]
-#[cfg(all(not(feature = "safe_mem"), feature = "unsafe_ptr"))]
+#[cfg_attr(feature = "nightly_doc", doc(cfg(unsafe··)))]
+#[cfg(all(not(feature = "safe_mem"), unsafe··))]
 impl Ptr {
     /// Copies `count * size_of::<T>()` bytes from `src` to `dst`. Can overlap.
     ///

src/sys/mem/slice/namespace.rs

@@ -50,8 +50,8 @@ impl<T> Slice<T> {
     /// See `core::slice::`[`from_raw_parts`]
     ///
     /// See also `Ptr::`[`slice_from_raw_parts`][crate::Ptr::slice_from_raw_parts].
-    #[cfg_attr(feature = "nightly_doc", doc(cfg(feature = "unsafe_slice")))]
-    #[cfg(all(not(feature = "safe_mem"), feature = "unsafe_slice"))]
+    #[cfg_attr(feature = "nightly_doc", doc(cfg(unsafe··)))]
+    #[cfg(all(not(feature = "safe_mem"), unsafe··))]
     pub const unsafe fn from_raw_parts<'a>(data: *const T, len: usize) -> &'a [T] {
         // SAFETY: Caller must uphold the safety contract.
         unsafe { from_raw_parts(data, len) }
@@ -63,8 +63,8 @@ impl<T> Slice<T> {
     /// See `core::slice::`[`from_raw_parts_mut`].
     ///
     /// See also `Ptr::`[`slice_from_raw_parts_mut`][crate::Ptr::slice_from_raw_parts_mut].
-    #[cfg_attr(feature = "nightly_doc", doc(cfg(feature = "unsafe_slice")))]
-    #[cfg(all(not(feature = "safe_mem"), feature = "unsafe_slice"))]
+    #[cfg_attr(feature = "nightly_doc", doc(cfg(unsafe··)))]
+    #[cfg(all(not(feature = "safe_mem"), unsafe··))]
     pub const unsafe fn from_raw_parts_mut<'a>(data: *mut T, len: usize) -> &'a mut [T] {
         // SAFETY: Caller must uphold the safety contract.
         unsafe { from_raw_parts_mut(data, len) }

src/text/str/namespace.rs

@@ -9,10 +9,10 @@ use crate::{
     iif, Ascii, InvalidUtf8, Slice,
     _core::str::{from_utf8, from_utf8_mut},
 };
-#[allow(unused_imports, reason = "unsafe_str only")]
+#[allow(unused_imports, reason = "unsafe")]
 #[cfg(feature = "alloc")]
 use crate::{Box, _dep::_alloc::str::from_boxed_utf8_unchecked};
-#[allow(unused_imports, reason = "unsafe_str only")]
+#[allow(unused_imports, reason = "unsafe")]
 use crate::{
     _core::str::{from_utf8_unchecked, from_utf8_unchecked_mut},
     sf, unwrap,
@@ -53,8 +53,8 @@ impl Str {
     /// # Safety
     /// The bytes passed in must be valid UTF-8.
     #[must_use]
-    #[cfg(all(not(feature = "safe_text"), feature = "unsafe_str"))]
-    #[cfg_attr(feature = "nightly_doc", doc(cfg(feature = "unsafe_str")))]
+    #[cfg(all(not(feature = "safe_text"), unsafe··))]
+    #[cfg_attr(feature = "nightly_doc", doc(cfg(unsafe··)))]
     pub const unsafe fn from_utf8_unchecked(v: &[u8]) -> &str {
         // SAFETY: Caller must uphold the safety contract.
         unsafe { from_utf8_unchecked(v) }
@@ -67,8 +67,8 @@ impl Str {
     /// # Safety
     /// The bytes passed in must be valid UTF-8.
     #[must_use]
-    #[cfg(all(not(feature = "safe_text"), feature = "unsafe_str"))]
-    #[cfg_attr(feature = "nightly_doc", doc(cfg(feature = "unsafe_str")))]
+    #[cfg(all(not(feature = "safe_text"), unsafe··))]
+    #[cfg_attr(feature = "nightly_doc", doc(cfg(unsafe··)))]
     pub const unsafe fn from_utf8_unchecked_mut(v: &mut [u8]) -> &mut str {
         // SAFETY: Caller must uphold the safety contract.
         unsafe { from_utf8_unchecked_mut(v) }
@@ -82,8 +82,8 @@ impl Str {
     /// The bytes passed in must be valid UTF-8.
     #[must_use]
     #[cfg(feature = "alloc")]
-    #[cfg(all(not(feature = "safe_text"), feature = "unsafe_str"))]
-    #[cfg_attr(feature = "nightly_doc", doc(cfg(all(feature = "alloc", feature = "unsafe_str"))))]
+    #[cfg(all(not(feature = "safe_text"), unsafe··))]
+    #[cfg_attr(feature = "nightly_doc", doc(cfg(all(feature = "alloc", unsafe··))))]
     pub unsafe fn from_boxed_utf8_unchecked(v: Box<[u8]>) -> Box<str> {
         // SAFETY: Caller must uphold the safety contract.
         unsafe { from_boxed_utf8_unchecked(v) }