diff --git a/library/std/src/sys/unix/fs.rs b/library/std/src/sys/unix/fs.rs
index acb18e6d064e6..59dfd9f9dc424 100644
--- a/library/std/src/sys/unix/fs.rs
+++ b/library/std/src/sys/unix/fs.rs
@@ -692,6 +692,7 @@ impl OpenOptions {
     }
 }
 
+
 impl File {
     pub fn open(path: &Path, opts: &OpenOptions) -> io::Result<File> {
         let path = cstr(path)?;
@@ -962,6 +963,12 @@ pub fn rename(old: &Path, new: &Path) -> io::Result<()> {
     Ok(())
 }
 
+pub fn get_openopetions_as_cint(from: OpenOptions) -> io::Result<libc::c_int> {
+    let access_mode = from.get_access_mode()?;
+    let creation_mode = from.get_creation_mode()?;
+    Ok(creation_mode | access_mode)
+}
+
 pub fn set_perm(p: &Path, perm: FilePermissions) -> io::Result<()> {
     let p = cstr(p)?;
     cvt_r(|| unsafe { libc::chmod(p.as_ptr(), perm.mode) })?;
diff --git a/src/doc/unstable-book/src/language-features/const-fn.md b/src/doc/unstable-book/src/language-features/const-fn.md
deleted file mode 100644
index 50dbbaf56743c..0000000000000
--- a/src/doc/unstable-book/src/language-features/const-fn.md
+++ /dev/null
@@ -1,29 +0,0 @@
-# `const_fn`
-
-The tracking issue for this feature is: [#57563]
-
-[#57563]: https://github.com/rust-lang/rust/issues/57563
-
-------------------------
-
-The `const_fn` feature allows marking free functions and inherent methods as
-`const`, enabling them to be called in constants contexts, with constant
-arguments.
-
-## Examples
-
-```rust
-#![feature(const_fn)]
-
-const fn double(x: i32) -> i32 {
-    x * 2
-}
-
-const FIVE: i32 = 5;
-const TEN: i32 = double(FIVE);
-
-fn main() {
-    assert_eq!(5, FIVE);
-    assert_eq!(10, TEN);
-}
-```