Add const to the sys getters; add issue number to #[unstable]

Author: Lucretiel

library/std/src/io/mod.rs

@@ -1509,7 +1509,7 @@ impl<'a> IoSlice<'a> {
     ///
     /// assert_eq!(io_slice.as_bytes(), b"def");
     /// ```
-    #[unstable(feature = "io_slice_as_bytes")]
+    #[unstable(feature = "io_slice_as_bytes", issue = "111277")]
     #[inline]
     #[must_use]
     pub const fn as_bytes(&self) -> &'a [u8] {

library/std/src/sys/pal/solid/io.rs

@@ -33,7 +33,7 @@ impl<'a> IoSlice<'a> {
     }
 
     #[inline]
-    pub fn as_slice(&self) -> &'a [u8] {
+    pub const fn as_slice(&self) -> &'a [u8] {
         unsafe { slice::from_raw_parts(self.vec.iov_base as *mut u8, self.vec.iov_len) }
     }
 }

library/std/src/sys/pal/unix/io.rs

@@ -33,7 +33,7 @@ impl<'a> IoSlice<'a> {
     }
 
     #[inline]
-    pub fn as_slice(&self) -> &'a [u8] {
+    pub const fn as_slice(&self) -> &'a [u8] {
         unsafe { slice::from_raw_parts(self.vec.iov_base as *mut u8, self.vec.iov_len) }
     }
 }

library/std/src/sys/pal/unsupported/io.rs

@@ -15,7 +15,7 @@ impl<'a> IoSlice<'a> {
     }
 
     #[inline]
-    pub fn as_slice(&self) -> &'a [u8] {
+    pub const fn as_slice(&self) -> &'a [u8] {
         self.0
     }
 }

library/std/src/sys/pal/wasi/io.rs

@@ -30,7 +30,7 @@ impl<'a> IoSlice<'a> {
     }
 
     #[inline]
-    pub fn as_slice(&self) -> &'a [u8] {
+    pub const fn as_slice(&self) -> &'a [u8] {
         unsafe { slice::from_raw_parts(self.vec.buf as *const u8, self.vec.buf_len) }
     }
 }