Auto merge of #137571 - tgross35:rollup-i1tcnv1, r=tgross35

Rollup of 8 pull requests

Successful merges:

 - #134655 (Stabilize `hash_extract_if`)
 - #135933 (Explain how Vec::with_capacity is faithful)
 - #136668 (Stabilize `core::str::from_utf8_mut` as `const`)
 - #136775 (Update `String::from_raw_parts` safety requirements)
 - #137109 (stabilize extract_if)
 - #137349 (Implement `read_buf` for zkVM stdin)
 - #137493 (configure.py: don't instruct user to run nonexistent program)
 - #137516 (remove some unnecessary rustc_const_unstable)

r? `@ghost`
`@rustbot` modify labels: rollup

library/std/src/collections/hash/map.rs

@@ -656,7 +656,6 @@ impl<K, V, S> HashMap<K, V, S> {
     /// Splitting a map into even and odd keys, reusing the original map:
     ///
     /// ```
-    /// #![feature(hash_extract_if)]
     /// use std::collections::HashMap;
     ///
     /// let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x)).collect();
@@ -672,7 +671,7 @@ impl<K, V, S> HashMap<K, V, S> {
     /// ```
     #[inline]
     #[rustc_lint_query_instability]
-    #[unstable(feature = "hash_extract_if", issue = "59618")]
+    #[stable(feature = "hash_extract_if", since = "CURRENT_RUSTC_VERSION")]
     pub fn extract_if<F>(&mut self, pred: F) -> ExtractIf<'_, K, V, F>
     where
         F: FnMut(&K, &mut V) -> bool,
@@ -1722,8 +1721,6 @@ impl<'a, K, V> Drain<'a, K, V> {
 /// # Example
 ///
 /// ```
-/// #![feature(hash_extract_if)]
-///
 /// use std::collections::HashMap;
 ///
 /// let mut map = HashMap::from([
@@ -1731,7 +1728,7 @@ impl<'a, K, V> Drain<'a, K, V> {
 /// ]);
 /// let iter = map.extract_if(|_k, v| *v % 2 == 0);
 /// ```
-#[unstable(feature = "hash_extract_if", issue = "59618")]
+#[stable(feature = "hash_extract_if", since = "CURRENT_RUSTC_VERSION")]
 #[must_use = "iterators are lazy and do nothing unless consumed"]
 pub struct ExtractIf<'a, K, V, F>
 where
@@ -2746,7 +2743,7 @@ where
     }
 }
 
-#[unstable(feature = "hash_extract_if", issue = "59618")]
+#[stable(feature = "hash_extract_if", since = "CURRENT_RUSTC_VERSION")]
 impl<K, V, F> Iterator for ExtractIf<'_, K, V, F>
 where
     F: FnMut(&K, &mut V) -> bool,
@@ -2763,10 +2760,10 @@ where
     }
 }
 
-#[unstable(feature = "hash_extract_if", issue = "59618")]
+#[stable(feature = "hash_extract_if", since = "CURRENT_RUSTC_VERSION")]
 impl<K, V, F> FusedIterator for ExtractIf<'_, K, V, F> where F: FnMut(&K, &mut V) -> bool {}
 
-#[unstable(feature = "hash_extract_if", issue = "59618")]
+#[stable(feature = "hash_extract_if", since = "CURRENT_RUSTC_VERSION")]
 impl<'a, K, V, F> fmt::Debug for ExtractIf<'a, K, V, F>
 where
     F: FnMut(&K, &mut V) -> bool,

library/std/src/collections/hash/set.rs

@@ -293,7 +293,6 @@ impl<T, S> HashSet<T, S> {
     /// Splitting a set into even and odd values, reusing the original set:
     ///
     /// ```
-    /// #![feature(hash_extract_if)]
     /// use std::collections::HashSet;
     ///
     /// let mut set: HashSet<i32> = (0..8).collect();
@@ -309,7 +308,7 @@ impl<T, S> HashSet<T, S> {
     /// ```
     #[inline]
     #[rustc_lint_query_instability]
-    #[unstable(feature = "hash_extract_if", issue = "59618")]
+    #[stable(feature = "hash_extract_if", since = "CURRENT_RUSTC_VERSION")]
     pub fn extract_if<F>(&mut self, pred: F) -> ExtractIf<'_, T, F>
     where
         F: FnMut(&T) -> bool,
@@ -1385,15 +1384,13 @@ pub struct Drain<'a, K: 'a> {
 /// # Examples
 ///
 /// ```
-/// #![feature(hash_extract_if)]
-///
 /// use std::collections::HashSet;
 ///
 /// let mut a = HashSet::from([1, 2, 3]);
 ///
 /// let mut extract_ifed = a.extract_if(|v| v % 2 == 0);
 /// ```
-#[unstable(feature = "hash_extract_if", issue = "59618")]
+#[stable(feature = "hash_extract_if", since = "CURRENT_RUSTC_VERSION")]
 pub struct ExtractIf<'a, K, F>
 where
     F: FnMut(&K) -> bool,
@@ -1676,7 +1673,7 @@ impl<K: fmt::Debug> fmt::Debug for Drain<'_, K> {
     }
 }
 
-#[unstable(feature = "hash_extract_if", issue = "59618")]
+#[stable(feature = "hash_extract_if", since = "CURRENT_RUSTC_VERSION")]
 impl<K, F> Iterator for ExtractIf<'_, K, F>
 where
     F: FnMut(&K) -> bool,
@@ -1693,10 +1690,10 @@ where
     }
 }
 
-#[unstable(feature = "hash_extract_if", issue = "59618")]
+#[stable(feature = "hash_extract_if", since = "CURRENT_RUSTC_VERSION")]
 impl<K, F> FusedIterator for ExtractIf<'_, K, F> where F: FnMut(&K) -> bool {}
 
-#[unstable(feature = "hash_extract_if", issue = "59618")]
+#[stable(feature = "hash_extract_if", since = "CURRENT_RUSTC_VERSION")]
 impl<'a, K, F> fmt::Debug for ExtractIf<'a, K, F>
 where
     F: FnMut(&K) -> bool,

library/std/src/sys/pal/zkvm/stdio.rs

@@ -1,6 +1,6 @@
 use super::abi;
 use super::abi::fileno;
-use crate::io;
+use crate::io::{self, BorrowedCursor};
 
 pub struct Stdin;
 pub struct Stdout;
@@ -16,6 +16,14 @@ impl io::Read for Stdin {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
         Ok(unsafe { abi::sys_read(fileno::STDIN, buf.as_mut_ptr(), buf.len()) })
     }
+
+    fn read_buf(&mut self, mut buf: BorrowedCursor<'_>) -> io::Result<()> {
+        unsafe {
+            let n = abi::sys_read(fileno::STDIN, buf.as_mut().as_mut_ptr().cast(), buf.capacity());
+            buf.advance_unchecked(n);
+        }
+        Ok(())
+    }
 }
 
 impl Stdout {