Rollup merge of #127586 - zachs18:more-must-use, r=cuviper

Add `#[must_use]` to some `into_raw*` functions.

cc #121287

r? ``@cuviper``

Adds `#[must_use = "losing the pointer will leak memory"]`[^1] to `Box::into_raw(_with_allocator)`, `Vec::into_raw_parts(_with_alloc)`, `String::into_raw_parts`[^2], and `rc::{Rc, Weak}::into_raw_with_allocator` (Rc's normal `into_raw` and all of `Arc`'s `into_raw*`s are already `must_use`).

Adds `#[must_use = "losing the raw <resource name may leak resources"]` to `IntoRawFd::into_raw_fd`, `IntoRawSocket::into_raw_socket`, and `IntoRawHandle::into_raw_handle`.

[^1]: "*will* leak memory" may be too-strong wording (since `Box`/`Vec`/`String`/`rc::Weak` might not have a backing allocation), but I left it as-is for simplicity and consistency.

[^2]: `String::into_raw_parts`'s `must_use` message is changed from the previous (possibly misleading) "`self` will be dropped if the result is not used".

1 files changed, 2 insertions, 0 deletions

diff --git a/library/std/src/os/windows/io/raw.rs b/library/std/src/os/windows/io/raw.rs
index 4ba07e3d2af..6658248d574 100644
--- a/library/std/src/os/windows/io/raw.rs
+++ b/library/std/src/os/windows/io/raw.rs
@@ -85,6 +85,7 @@ pub trait IntoRawHandle {
     /// However, transferring ownership is not strictly required. Use a
     /// `Into<OwnedHandle>::into` implementation for an API which strictly
     /// transfers ownership.
+    #[must_use = "losing the raw handle may leak resources"]
     #[stable(feature = "into_raw_os", since = "1.4.0")]
     fn into_raw_handle(self) -> RawHandle;
 }
@@ -228,6 +229,7 @@ pub trait IntoRawSocket {
     /// However, transferring ownership is not strictly required. Use a
     /// `Into<OwnedSocket>::into` implementation for an API which strictly
     /// transfers ownership.
+    #[must_use = "losing the raw socket may leak resources"]
     #[stable(feature = "into_raw_os", since = "1.4.0")]
     fn into_raw_socket(self) -> RawSocket;
 }