From 6d7211738d74436a5d36ca68948d86f4809b9001 Mon Sep 17 00:00:00 2001
From: Dan Gohman <dev@sunfishcode.online>
Date: Tue, 27 Jul 2021 17:15:40 -0700
Subject: [PATCH] Add Safety comments to the `As*` for `Owned*`
 implementations.

---
 library/std/src/os/unix/io/fd.rs        | 3 +++
 library/std/src/os/wasi/io/fd.rs        | 3 +++
 library/std/src/os/windows/io/handle.rs | 3 +++
 library/std/src/os/windows/io/socket.rs | 3 +++
 4 files changed, 12 insertions(+)

diff --git a/library/std/src/os/unix/io/fd.rs b/library/std/src/os/unix/io/fd.rs
index 2be6198092f..22b1151b92a 100644
--- a/library/std/src/os/unix/io/fd.rs
+++ b/library/std/src/os/unix/io/fd.rs
@@ -178,6 +178,9 @@ fn as_fd(&self) -> BorrowedFd<'_> {
 impl AsFd for OwnedFd {
     #[inline]
     fn as_fd(&self) -> BorrowedFd<'_> {
+        // Safety: `OwnedFd` and `BorrowedFd` have the same validity
+        // invariants, and the `BorrowdFd` is bounded by the lifetime
+        // of `&self`.
         unsafe { BorrowedFd::borrow_raw_fd(self.as_raw_fd()) }
     }
 }
diff --git a/library/std/src/os/wasi/io/fd.rs b/library/std/src/os/wasi/io/fd.rs
index f77a73abb90..e07c2e12b7d 100644
--- a/library/std/src/os/wasi/io/fd.rs
+++ b/library/std/src/os/wasi/io/fd.rs
@@ -177,6 +177,9 @@ fn as_fd(&self) -> BorrowedFd<'_> {
 impl AsFd for OwnedFd {
     #[inline]
     fn as_fd(&self) -> BorrowedFd<'_> {
+        // Safety: `OwnedFd` and `BorrowedFd` have the same validity
+        // invariants, and the `BorrowdFd` is bounded by the lifetime
+        // of `&self`.
         unsafe { BorrowedFd::borrow_raw_fd(self.as_raw_fd()) }
     }
 }
diff --git a/library/std/src/os/windows/io/handle.rs b/library/std/src/os/windows/io/handle.rs
index 5d250520685..87fbd3e0460 100644
--- a/library/std/src/os/windows/io/handle.rs
+++ b/library/std/src/os/windows/io/handle.rs
@@ -282,6 +282,9 @@ fn as_handle(&self) -> BorrowedHandle<'_> {
 impl AsHandle for OwnedHandle {
     #[inline]
     fn as_handle(&self) -> BorrowedHandle<'_> {
+        // Safety: `OwnedHandle` and `BorrowedHandle` have the same validity
+        // invariants, and the `BorrowdHandle` is bounded by the lifetime
+        // of `&self`.
         unsafe { BorrowedHandle::borrow_raw_handle(self.as_raw_handle()) }
     }
 }
diff --git a/library/std/src/os/windows/io/socket.rs b/library/std/src/os/windows/io/socket.rs
index fd89f4cc60c..23db66df09f 100644
--- a/library/std/src/os/windows/io/socket.rs
+++ b/library/std/src/os/windows/io/socket.rs
@@ -145,6 +145,9 @@ fn as_socket(&self) -> BorrowedSocket<'_> {
 impl AsSocket for OwnedSocket {
     #[inline]
     fn as_socket(&self) -> BorrowedSocket<'_> {
+        // Safety: `OwnedSocket` and `BorrowedSocket` have the same validity
+        // invariants, and the `BorrowdSocket` is bounded by the lifetime
+        // of `&self`.
         unsafe { BorrowedSocket::borrow_raw_socket(self.as_raw_socket()) }
     }
 }